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1
Inheritance
4
Pathophys.
28
Phenotypes
4
Pathograph
1
Genes
3
Treatments
1
References
1
Deep Research
👪

Inheritance

1
Autosomal recessive HP:0000007
Opsismodysplasia follows autosomal recessive inheritance with biallelic INPPL1 mutations required for disease expression. Consanguinity has been reported in multiple families. INPPL1 mutations explain approximately 60% of clinically diagnosed cases.
Autosomal recessive inheritance
Show evidence (2 references)
PMID:23273567 SUPPORT Human Clinical
"mutations in inositol polyphosphate phosphatase-like 1 (INPPL1) cause opsismodysplasia with or without renal phosphate wasting."
Establishes that biallelic INPPL1 mutations cause autosomal recessive opsismodysplasia.
PMID:10076884 SUPPORT Human Clinical
"This observation supports the hypothesis of autosomal recessive transmission of opsismodysplasia."
Familial recurrence pattern confirmed autosomal recessive inheritance prior to gene identification.

Pathophysiology

4
Loss of SHIP2 phosphoinositide phosphatase activity
INPPL1 encodes SHIP2, a phosphoinositide 5-phosphatase that dephosphorylates PI(3,4,5)P3 to generate PI(3,4)P2. Loss-of-function mutations in INPPL1 abolish this catalytic activity, disrupting both PI(3,4,5)P3 turnover and PI(3,4)P2 product-dependent phosphoinositide signaling in chondrocytes. Most pathogenic variants are premature stop codons or missense mutations affecting the catalytic domain, while some destabilize the protein through structural disruption of the SH2 domain.
Chondrocyte link
Phosphatidylinositol dephosphorylation link ↓ DECREASED
Show evidence (4 references)
PMID:23273569 SUPPORT Human Clinical
"INPPL1 belongs to the inositol-1,4,5-trisphosphate 5-phosphatase family, a family of signal-modulating enzymes that govern a plethora of cellular functions by regulating the levels of specific phosphoinositides."
Identifies the enzymatic function of INPPL1/SHIP2 in phosphoinositide signaling.
PMID:27708270 SUPPORT Human Clinical
"skeletal disease seems to result from the loss of SHIP2 activity due to catalytic domain mutations or no SHIP2 protein due to premature stop codons."
Confirms that loss of SHIP2 enzymatic activity is the pathogenic mechanism.
PMID:24953221 SUPPORT In Vitro
"the INPPL1 protein was barely detectable in patient cells."
Patient-derived lymphocytes show that the SH2-domain insertion destabilizes INPPL1 protein, supporting loss of SHIP2 activity as a disease mechanism.
+ 1 more reference
Impaired chondrocyte differentiation and endochondral ossification
Loss of SHIP2 activity leads to elevated MEK-Erk1/2 signaling in chondrocytes, resulting in altered chondrocyte differentiation and impaired matrix mineralization. Growth plate histology shows a widened hypertrophic zone with irregular provisional calcification and disrupted vascular invasion. These defects impair endochondral ossification, the process by which cartilage is replaced by bone during skeletal development.
Hypertrophic chondrocyte link Chondrocyte link
Endochondral ossification link ↓ DECREASED Chondrocyte differentiation link ⚠ ABNORMAL MAPK cascade link ↑ INCREASED Bone mineralization link ↓ DECREASED
Show evidence (4 references)
PMID:31519471 SUPPORT Model Organism
"levels of p-MEK and p-Erk1/2 were significantly increased in SHIP2-inactivated chondrocytes in response to serum and IGF-1, but not to FGF2, as compared to control chondrocytes."
Mouse model demonstrates that SHIP2 loss increases MEK-Erk1/2 signaling in chondrocytes.
PMID:31519471 SUPPORT Model Organism
"Treatment of chondrocytes and bones in culture with a MEK inhibitor partially rescued the production of mineralized nodules, the size of the hypertrophic chondrocyte zone and bone growth, raising the possibility of a treatment that could partially reduce the phenotype of this severe condition."
MEK inhibition partially restores mineralization, confirming MEK-Erk1/2 pathway involvement.
PMID:6496568 SUPPORT Human Clinical
"The growth cartilage studied in one case showed a wide hypertrophic area containing thick connective tissue septa, irregular provisional calcification, and vascular invasion."
Original description of growth plate histopathology in opsismodysplasia.
+ 1 more reference
Defective cell migration and adhesion
SHIP2 loss disrupts phosphoinositide-dependent cell migration and adhesion signaling. Patient-derived fibroblasts show markedly reduced cell migration and altered adhesion properties, suggesting that these cellular defects contribute to impaired endochondral ossification by disrupting the normal movement and organization of chondrocytes in the growth plate.
Fibroblast link
Cell migration link ↓ DECREASED Cell adhesion link ⚠ ABNORMAL
Show evidence (2 references)
PMID:28869677 SUPPORT In Vitro
"cell migration is very much decreased in fibroblasts derived from three OPS patients as compared with control individuals."
Patient fibroblasts directly demonstrate impaired migration due to SHIP2 deficiency.
PMID:28869677 SUPPORT In Vitro
"signaling events linked to migration and particularly to adhesion, which are lost in OPS patients, would prevent normal endochondral ossification."
Links cell migration and adhesion defects to the skeletal phenotype.
Renal phosphate wasting
A subset of patients develops renal phosphate wasting with elevated FGF23 levels, leading to hypophosphatemic rickets. Phosphate wasting is associated with more severe bone demineralization and a more severe overall phenotype. The mechanism linking SHIP2 loss to FGF23 elevation and renal phosphate handling is not fully understood.
Phosphate ion homeostasis link ⚠ ABNORMAL
Show evidence (2 references)
PMID:17315533 SUPPORT Human Clinical
"We now demonstrate an association between opsismodysplasia, hypophosphatemic rickets, and FGF23 elevation."
First report demonstrating the link between opsismodysplasia and FGF23-mediated phosphate wasting.
PMID:26157786 SUPPORT Human Clinical
"Renal phosphate wasting is associated with severe bone demineralization and a more severe phenotype."
Establishes that phosphate wasting worsens the skeletal phenotype.

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Opsismodysplasia Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.

Phenotypes

28
Head and Neck 8
Relative macrocephaly Relative macrocephaly (HP:0004482)
Show evidence (1 reference)
PMID:39911177 SUPPORT Human Clinical
"He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
Recent case evidence documents relative macrocephaly as part of the characteristic craniofacial gestalt.
Large fontanelles Large fontanelles (HP:0000239)
Show evidence (1 reference)
PMID:24953221 SUPPORT Human Clinical
"She had wide open anterior fontanelles which closed at six years of age."
This patient report shows persistent large fontanelles well beyond infancy.
Frontal bossing Frontal bossing (HP:0002007)
Show evidence (1 reference)
PMID:34094554 SUPPORT Human Clinical
"Opsismodysplasia is an autosomal recessive osteochondrodysplasia disorders characterized by a severe delay in bone maturation. This leads to rhizomelic micromelia with small hands and feet, relative macrocephaly, and craniofacial dysmorphism including frontal bossing, short nose with anteverted..."
Prenatal imaging demonstrates frontal bossing in an affected fetus.
Midface retrusion Midface retrusion (HP:0011800)
Show evidence (1 reference)
PMID:39911177 SUPPORT Human Clinical
"He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
The reported midface hypoplasia corresponds to the characteristic midfacial retrusion seen in opsismodysplasia.
Depressed nasal bridge Depressed nasal bridge (HP:0005280)
Show evidence (1 reference)
PMID:39911177 SUPPORT Human Clinical
"He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
The depressed nasal bridge is explicitly reported in a recent molecularly confirmed case.
Short nose Short nose (HP:0003196)
Show evidence (1 reference)
PMID:34094554 SUPPORT Human Clinical
"Examination of the newborn (case A) shows short limbs with small trident hands and feet, and craniofacial dysmorphism including hypertelorism, depressed nasal bridge, short nose with anteverted nares and depressed nasal bridge, long philtrum, and low set deformed ears."
The postnatal examination in a molecularly confirmed newborn documents a short nose.
Anteverted nares Anteverted nares (HP:0000463)
Show evidence (1 reference)
PMID:34094554 SUPPORT Human Clinical
"Examination of the newborn (case A) shows short limbs with small trident hands and feet, and craniofacial dysmorphism including hypertelorism, depressed nasal bridge, short nose with anteverted nares and depressed nasal bridge, long philtrum, and low set deformed ears."
The newborn examination explicitly reports anteverted nares.
Long philtrum Long philtrum (HP:0000343)
Show evidence (1 reference)
PMID:39911177 SUPPORT Human Clinical
"He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
The long philtrum is part of the recurrent craniofacial phenotype.
Limbs 5
Micromelia Micromelia (HP:0002983)
Show evidence (1 reference)
PMID:23273569 SUPPORT Human Clinical
"Opsismodysplasia (OPS) is a severe autosomal-recessive chondrodysplasia characterized by pre- and postnatal micromelia with extremely short hands and feet."
Micromelia with short hands and feet is a defining feature.
Context-specific annotations (1)
Onset: ANTENATAL
Show evidence (1 reference)
PMID:23273569 SUPPORT Human Clinical
"Opsismodysplasia (OPS) is a severe autosomal-recessive chondrodysplasia characterized by pre- and postnatal micromelia with extremely short hands and feet."
Directly supports antenatal onset of micromelia.
Metaphyseal cupping Metaphyseal cupping (HP:0003021)
Show evidence (1 reference)
PMID:23273569 SUPPORT Human Clinical
"The main radiological features are severe platyspondyly, squared metacarpals, delayed skeletal ossification, and metaphyseal cupping."
The defining molecular cohort lists metaphyseal cupping among the main radiographic abnormalities.
Bowing of the long bones Bowing of the long bones (HP:0006487)
Show evidence (1 reference)
PMID:27233067 SUPPORT Human Clinical
"Radiographs of fetus #2 showed hydropic changes and short limbs with flaring and metaphyseal cupping were reported. Both distal femoral metaphyses appeared irregular and the radii, femora and tibae were bowed (Figure 1)."
Prenatal radiographs in a severe familial case document bowing of multiple long bones.
Short foot Short foot (HP:0001773)
Show evidence (1 reference)
PMID:6496568 SUPPORT Human Clinical
"very retarded bone maturation; marked shortness of the bones of the hands and of the feet with concave metaphyses; and thin, lamellar vertebral bodies."
Short feet with concave metaphyses are defining features from the original description.
Short metacarpal Short metacarpal (HP:0010049)
Show evidence (1 reference)
PMID:39911177 SUPPORT Human Clinical
"Delayed bone age, short metacarpals and phalanges, wide and irregular metaphysis, platyspondyly, anterior beaking of the vertebrae, T12 vertebral hypoplasia, and acetabular dysplasia were noted on X-rays."
This recent molecularly confirmed case documents the characteristic marked shortening of the metacarpals.
Metabolism 1
Hypophosphatemic rickets Hypophosphatemic rickets (HP:0004912)
Show evidence (2 references)
PMID:17315533 SUPPORT Human Clinical
"Both children had hypophosphatemia, decreased TRP, and rickets."
Documents hypophosphatemic rickets in opsismodysplasia patients.
PMID:17315533 SUPPORT Human Clinical
"We now demonstrate an association between opsismodysplasia, hypophosphatemic rickets, and FGF23 elevation."
Establishes the association with FGF23-mediated phosphate wasting.
Musculoskeletal 6
Delayed skeletal maturation Delayed skeletal maturation (HP:0002750)
Show evidence (1 reference)
PMID:6496568 SUPPORT Human Clinical
"very retarded bone maturation; marked shortness of the bones of the hands and of the feet with concave metaphyses; and thin, lamellar vertebral bodies."
Original disease description emphasizing delayed bone maturation as a cardinal feature.
Delayed epiphyseal ossification Delayed epiphyseal ossification (HP:0002663)
Show evidence (1 reference)
PMID:26157786 SUPPORT Human Clinical
"The main radiological features are severe platyspondyly, short long bones including squared metacarpals, delayed epiphyseal ossification, and metaphyseal flaring and cupping (7–10)."
This case-based review directly identifies delayed epiphyseal ossification as a core radiographic abnormality.
Narrow chest Narrow chest (HP:0000774)
Show evidence (1 reference)
PMID:34094554 SUPPORT Human Clinical
"Chest appears narrow and abdomen is protuberant."
Prenatal imaging demonstrates a narrow thorax in severe opsismodysplasia.
Scoliosis Scoliosis (HP:0002650)
Show evidence (1 reference)
PMID:26157786 SUPPORT Human Clinical
"She was identified to have scoliosis with a 42° right thoracic curve, and a 57° left lumbar curve."
Detailed follow-up of a surviving child documents clinically significant scoliosis.
Hypoplasia of the odontoid process Hypoplasia of the odontoid process (HP:0003311)
Show evidence (1 reference)
PMID:26157786 SUPPORT Human Clinical
"Cervical spine films show odontoid hypoplasia, with no evidence of atlantoaxial or occipitocervical instability."
Follow-up cervical imaging in a surviving child documented odontoid hypoplasia.
Reduced bone mineral density Reduced bone mineral density (HP:0004349)
Show evidence (2 references)
PMID:26157786 SUPPORT Human Clinical
"Renal phosphate wasting is associated with severe bone demineralization and a more severe phenotype."
Bone demineralization is a feature, exacerbated by phosphate wasting.
PMID:40620719 SUPPORT Human Clinical
"Initial evaluations showed severe short stature and low bone mineral density (DEXA SDS: -3.16)."
Recent case evidence shows reduced bone mineral density even without hypophosphatemic rickets.
Nervous System 2
Hydrocephalus Hydrocephalus (HP:0000238)
Show evidence (1 reference)
PMID:16473316 SUPPORT Human Clinical
"She also had hydrocephaly, a rare finding in opsismodysplasia."
This report supports hydrocephalus as an uncommon but documented associated feature.
Motor delay Motor delay (HP:0001270)
Show evidence (1 reference)
PMID:24953221 SUPPORT Human Clinical
"She achieved neuromotor developmental milestones late."
This long-term follow-up report documents delayed motor milestone acquisition.
Prenatal and Birth 1
Polyhydramnios Polyhydramnios (HP:0001561)
Show evidence (1 reference)
PMID:20422326 SUPPORT Human Clinical
"During the antenatal period, polyhydramnios was noted."
This neonatal case report documents polyhydramnios as a prenatal finding.
Respiratory 1
Respiratory insufficiency Respiratory insufficiency (HP:0002093)
Show evidence (1 reference)
PMID:26157786 SUPPORT Human Clinical
"These cases provide evidence of the variability in severity of findings in siblings with opsismodysplasia and suggest that those with phosphate wasting have more severe skeletal findings and respiratory compromise."
The sibling case report identifies respiratory compromise as a major clinical complication.
Growth 1
Severe short stature Severe short stature (HP:0003510)
Show evidence (1 reference)
PMID:40620719 SUPPORT Human Clinical
"Initial evaluations showed severe short stature and low bone mineral density (DEXA SDS: -3.16)."
Recent case evidence confirms severe short stature as a core phenotype.
Other 3
Severe platyspondyly Severe platyspondyly (HP:0004565)
Show evidence (1 reference)
PMID:23273569 SUPPORT Human Clinical
"The main radiological features are severe platyspondyly, squared metacarpals, delayed skeletal ossification, and metaphyseal cupping."
The landmark molecular cohort identifies severe platyspondyly as a main radiographic feature.
Flat acetabular roof Flat acetabular roof (HP:0003180)
Show evidence (1 reference)
PMID:27233067 SUPPORT Human Clinical
"The iliac bones were decreased in vertical height with horizontal orientation of the acetabular roofs."
This radiographic description directly supports a flat acetabular roof phenotype.
Renal phosphate wasting Renal phosphate wasting (HP:0000117)
Show evidence (1 reference)
PMID:23273567 SUPPORT Human Clinical
"Opsismodysplasia is a rare, autosomal-recessive skeletal dysplasia characterized by short stature, characteristic facial features, and in some cases severe renal phosphate wasting."
The gene discovery study identifies renal phosphate wasting as a clinically important subset phenotype.
🧬

Genetic Associations

1
INPPL1 biallelic variants (Causative)
Autosomal recessive
Show evidence (4 references)
PMID:23273569 SUPPORT Human Clinical
"Opsismodysplasia (OPS) is a severe autosomal-recessive chondrodysplasia characterized by pre- and postnatal micromelia with extremely short hands and feet."
Landmark study identifying INPPL1 mutations as the cause of opsismodysplasia.
PMID:23273567 SUPPORT Human Clinical
"INPPL1 mutations explain ~60% of cases overall, including both of the families in our cohort with more than one affected child and 50% of the simplex cases."
Estimates the proportion of clinically diagnosed cases attributable to INPPL1 mutations.
PMID:34094554 SUPPORT Human Clinical
"Schneckenbecken dysplasia and Opsismodysplasia are allelic disorders caused by pathogenic variants in INPPL1 gene with lethal outcomes in Schneckenbecken dysplasia and nonlethal prognosis in Opsismodysplasia."
Establishes the allelic relationship with Schneckenbecken dysplasia.
+ 1 more reference
💊

Treatments

3
Bisphosphonate therapy
Action: bisphosphonate agent therapy MAXO:0000954
Intravenous pamidronate has improved bone mineral density and gross motor function in patients with opsismodysplasia. Treatment benefit has been demonstrated both in patients with and without hypophosphatemic rickets.
Show evidence (4 references)
PMID:26157786 SUPPORT Human Clinical
"This report represents the first described cases of opsismodysplasia treated with intravenous bisphosphonate (pamidronate)."
First report of bisphosphonate use in opsismodysplasia.
PMID:26157786 SUPPORT Human Clinical
"At 10 years of age, he has stopped taking his wheelchair to school and runs during recess, demonstrating a remarkable progress presumably related to his pamidronate usage."
Demonstrates functional motor improvement with bisphosphonate therapy.
PMID:40504975 SUPPORT Human Clinical
"Intravenous bisphosphonate therapy has improved bone mineral density and gross motor function in two individuals with INPPL1-related opsismodysplasia."
GeneReviews confirms bisphosphonate benefit for bone density and motor function.
+ 1 more reference
Phosphate and calcitriol supplementation
Action: Pharmacotherapy NCIT:C15986
Oral phosphorus and calcitriol supplementation for patients with renal phosphate wasting and hypophosphatemic rickets.
Show evidence (1 reference)
PMID:17315533 SUPPORT Human Clinical
"Oral phosphorus and calcitriol improved metaphyseal mineralization, yet serum phosphate levels remained relatively low and renal phosphate wasting persisted."
Directly documents the treatment response to phosphate and calcitriol supplementation.
Multidisciplinary Surveillance and Supportive Care
Action: supportive care MAXO:0000950
Longitudinal supportive care monitors and manages fracture risk, cervical spine instability or cord compression, scoliosis, respiratory insufficiency or sleep apnea, swallowing and feeding issues, delayed gross motor skills, bone demineralization, and renal phosphate wasting. Care is coordinated across skeletal-dysplasia orthopedics/neurosurgery, endocrinology, pulmonology, rehabilitation medicine, physical therapy, occupational therapy, and other specialists as indicated.
Show evidence (4 references)
PMID:40504975 SUPPORT Human Clinical
"Complications include increased risk of fractures, cervical spine abnormalities, scoliosis, bone pain, respiratory issues, and delayed gross motor skills."
GeneReviews identifies the longitudinal complication targets for supportive care and surveillance.
PMID:40504975 SUPPORT Human Clinical
"Cervical spine complications should be managed by specialists familiar with skeletal dysplasias involving the spine including an orthopedist and neurosurgeon; surgical stabilization should be performed to prevent progressive myelopathy"
This supports specialist cervical-spine surveillance and escalation to surgical stabilization when progressive myelopathy risk is present.
PMID:40504975 SUPPORT Human Clinical
"Clinical examination for scoliosis every six to 12 months with radiographs when indicated; endocrinology evaluation for hypophosphatemia and renal phosphate wasting every six to 12 months and when indicated"
GeneReviews provides frequency guidance for scoliosis and renal-phosphate surveillance.
+ 1 more reference
{ }

Source YAML

click to show
name: Opsismodysplasia
creation_date: "2026-04-02T00:00:00Z"
updated_date: "2026-04-19T02:21:57Z"
category: Mendelian
description: >
  Opsismodysplasia is a rare autosomal recessive skeletal chondrodysplasia.
  Molecularly confirmed INPPL1-related opsismodysplasia is caused by biallelic
  loss-of-function mutations in INPPL1, which encodes the phosphoinositide
  5-phosphatase SHIP2. The disease is characterized by prenatal-onset short
  stature, micromelia with extremely short hands and feet, platyspondyly, delayed
  skeletal maturation, and distinctive craniofacial features including relative
  macrocephaly, frontal bossing, midface retrusion, and anteverted nares. Growth
  plate histology shows a widened hypertrophic zone with irregular provisional
  calcification. Loss of SHIP2 catalytic activity disrupts phosphoinositide
  signaling, leading to elevated MEK-Erk1/2 activity in chondrocytes, impaired
  chondrocyte differentiation, and defective endochondral ossification. Some
  patients develop renal phosphate wasting with hypophosphatemic rickets, which
  is associated with a more severe phenotype. Prognosis is variable, with
  perinatal demise in some infants and survival into childhood and beyond in
  others. Bisphosphonate therapy has shown benefit for bone mineral density and
  motor function.
disease_term:
  preferred_term: opsismodysplasia
  term:
    id: MONDO:0009785
    label: opsismodysplasia
parents:
- Spondylodysplastic dysplasia
- INPPL1-related skeletal dysplasia
inheritance:
- name: Autosomal recessive
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  description: >
    Opsismodysplasia follows autosomal recessive inheritance with biallelic
    INPPL1 mutations required for disease expression. Consanguinity has been
    reported in multiple families. INPPL1 mutations explain approximately 60%
    of clinically diagnosed cases.
  evidence:
  - reference: PMID:23273567
    reference_title: "Whole-genome analysis reveals that mutations in inositol polyphosphate phosphatase-like 1 cause opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "mutations in inositol polyphosphate phosphatase-like 1 (INPPL1) cause opsismodysplasia with or without renal phosphate wasting."
    explanation: Establishes that biallelic INPPL1 mutations cause autosomal recessive opsismodysplasia.
  - reference: PMID:10076884
    reference_title: "Five familial cases of opsismodysplasia substantiate the hypothesis of autosomal recessive inheritance."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This observation supports the hypothesis of autosomal recessive transmission of opsismodysplasia."
    explanation: Familial recurrence pattern confirmed autosomal recessive inheritance prior to gene identification.
prevalence:
- population: Global
  percentage: Unknown
  notes: >-
    Extremely rare with fewer than 40 molecularly confirmed cases reported
    worldwide as of 2025.
  evidence:
  - reference: PMID:39911177
    reference_title: "A Case of Opsismodysplasia with a Novel INPPL1 Variant."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Only 38 patients with a confirmed molecular diagnosis have been reported so far."
    explanation: Indicates extreme rarity of molecularly confirmed cases.
pathophysiology:
- name: Loss of SHIP2 phosphoinositide phosphatase activity
  description: >
    INPPL1 encodes SHIP2, a phosphoinositide 5-phosphatase that dephosphorylates
    PI(3,4,5)P3 to generate PI(3,4)P2. Loss-of-function mutations in INPPL1
    abolish this catalytic activity, disrupting both PI(3,4,5)P3 turnover and
    PI(3,4)P2 product-dependent phosphoinositide signaling in chondrocytes. Most
    pathogenic variants are premature stop codons or missense mutations affecting
    the catalytic domain, while some destabilize the protein through structural
    disruption of the SH2 domain.
  gene:
    preferred_term: INPPL1
    description: >
      Inositol polyphosphate phosphatase-like 1, encoding the lipid phosphatase
      SHIP2 that regulates phosphoinositide signaling by dephosphorylating
      PI(3,4,5)P3.
    modifier: DECREASED
    term:
      id: hgnc:6080
      label: INPPL1
  cell_types:
  - preferred_term: Chondrocyte
    term:
      id: CL:0000138
      label: chondrocyte
  biological_processes:
  - preferred_term: Phosphatidylinositol dephosphorylation
    term:
      id: GO:0046856
      label: phosphatidylinositol dephosphorylation
    modifier: DECREASED
  evidence:
  - reference: PMID:23273569
    reference_title: "Exome sequencing identifies INPPL1 mutations as a cause of opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "INPPL1 belongs to the inositol-1,4,5-trisphosphate 5-phosphatase family, a family of signal-modulating enzymes that govern a plethora of cellular functions by regulating the levels of specific phosphoinositides."
    explanation: Identifies the enzymatic function of INPPL1/SHIP2 in phosphoinositide signaling.
  - reference: PMID:27708270
    reference_title: "INPPL1 gene mutations in opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "skeletal disease seems to result from the loss of SHIP2 activity due to catalytic domain mutations or no SHIP2 protein due to premature stop codons."
    explanation: Confirms that loss of SHIP2 enzymatic activity is the pathogenic mechanism.
  - reference: PMID:24953221
    reference_title: "Opsismodysplasia resulting from an insertion mutation in the SH2 domain, which destabilizes INPPL1."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "the INPPL1 protein was barely detectable in patient cells."
    explanation: Patient-derived lymphocytes show that the SH2-domain insertion destabilizes INPPL1 protein, supporting loss of SHIP2 activity as a disease mechanism.
  - reference: PMID:27233067
    reference_title: "Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The absence of SHIP2 was confirmed by immunoblot analysis of proband amniocytes."
    explanation: Direct protein-level evidence showing complete loss of SHIP2 in a patient with compound heterozygous INPPL1 variants.
  downstream:
  - target: Impaired chondrocyte differentiation and endochondral ossification
    description: Loss of SHIP2 function directly perturbs chondrocyte differentiation programs and downstream endochondral bone formation.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:31519471
      reference_title: "Altered chondrocyte differentiation, matrix mineralization and MEK-Erk1/2 signaling in an INPPL1 catalytic knock-out mouse model of opsismodysplasia."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "They also highlight the important role of SHIP2 in chondrocytes during endochondral ossification and its different differentiation steps."
      explanation: The catalytic knock-out mouse directly links SHIP2 loss to abnormal chondrocyte differentiation and impaired endochondral ossification.
  - target: Defective cell migration and adhesion
    description: SHIP2 deficiency directly perturbs phosphoinositide-dependent migration and adhesion signaling in patient-derived cells.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:28869677
      reference_title: "Fibroblasts derived from patients with opsismodysplasia display SHIP2-specific cell migration and adhesion defects."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "We conclude that both migration and adhesion are very much disrupted in OPS-derived fibroblasts."
      explanation: Patient fibroblasts directly connect SHIP2 deficiency to combined migration and adhesion defects.
- name: Impaired chondrocyte differentiation and endochondral ossification
  description: >
    Loss of SHIP2 activity leads to elevated MEK-Erk1/2 signaling in chondrocytes,
    resulting in altered chondrocyte differentiation and impaired matrix mineralization.
    Growth plate histology shows a widened hypertrophic zone with irregular
    provisional calcification and disrupted vascular invasion. These defects impair
    endochondral ossification, the process by which cartilage is replaced by bone
    during skeletal development.
  cell_types:
  - preferred_term: Hypertrophic chondrocyte
    term:
      id: CL:0000743
      label: hypertrophic chondrocyte
  - preferred_term: Chondrocyte
    term:
      id: CL:0000138
      label: chondrocyte
  biological_processes:
  - preferred_term: Endochondral ossification
    term:
      id: GO:0001958
      label: endochondral ossification
    modifier: DECREASED
  - preferred_term: Chondrocyte differentiation
    term:
      id: GO:0002062
      label: chondrocyte differentiation
    modifier: ABNORMAL
  - preferred_term: MAPK cascade
    term:
      id: GO:0000165
      label: MAPK cascade
    modifier: INCREASED
  - preferred_term: Bone mineralization
    term:
      id: GO:0030282
      label: bone mineralization
    modifier: DECREASED
  evidence:
  - reference: PMID:31519471
    reference_title: "Altered chondrocyte differentiation, matrix mineralization and MEK-Erk1/2 signaling in an INPPL1 catalytic knock-out mouse model of opsismodysplasia."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "levels of p-MEK and p-Erk1/2 were significantly increased in SHIP2-inactivated chondrocytes in response to serum and IGF-1, but not to FGF2, as compared to control chondrocytes."
    explanation: Mouse model demonstrates that SHIP2 loss increases MEK-Erk1/2 signaling in chondrocytes.
  - reference: PMID:31519471
    reference_title: "Altered chondrocyte differentiation, matrix mineralization and MEK-Erk1/2 signaling in an INPPL1 catalytic knock-out mouse model of opsismodysplasia."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Treatment of chondrocytes and bones in culture with a MEK inhibitor partially rescued the production of mineralized nodules, the size of the hypertrophic chondrocyte zone and bone growth, raising the possibility of a treatment that could partially reduce the phenotype of this severe condition."
    explanation: MEK inhibition partially restores mineralization, confirming MEK-Erk1/2 pathway involvement.
  - reference: PMID:6496568
    reference_title: "Opsismodysplasia: a new type of chondrodysplasia with predominant involvement of the bones of the hand and the vertebrae."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The growth cartilage studied in one case showed a wide hypertrophic area containing thick connective tissue septa, irregular provisional calcification, and vascular invasion."
    explanation: Original description of growth plate histopathology in opsismodysplasia.
  - reference: PMID:23273569
    reference_title: "Exome sequencing identifies INPPL1 mutations as a cause of opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our finding of INPPL1 mutations in OPS, a severe spondylodysplastic dysplasia with major growth plate disorganization, supports a key and specific role of this enzyme in endochondral ossification."
    explanation: Links INPPL1 mutations to growth plate disorganization and impaired endochondral bone formation.
- name: Defective cell migration and adhesion
  description: >
    SHIP2 loss disrupts phosphoinositide-dependent cell migration and adhesion
    signaling. Patient-derived fibroblasts show markedly reduced cell migration
    and altered adhesion properties, suggesting that these cellular defects
    contribute to impaired endochondral ossification by disrupting the normal
    movement and organization of chondrocytes in the growth plate.
  cell_types:
  - preferred_term: Fibroblast
    term:
      id: CL:0000057
      label: fibroblast
  biological_processes:
  - preferred_term: Cell migration
    term:
      id: GO:0016477
      label: cell migration
    modifier: DECREASED
  - preferred_term: Cell adhesion
    term:
      id: GO:0007155
      label: cell adhesion
    modifier: ABNORMAL
  evidence:
  - reference: PMID:28869677
    reference_title: "Fibroblasts derived from patients with opsismodysplasia display SHIP2-specific cell migration and adhesion defects."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "cell migration is very much decreased in fibroblasts derived from three OPS patients as compared with control individuals."
    explanation: Patient fibroblasts directly demonstrate impaired migration due to SHIP2 deficiency.
  - reference: PMID:28869677
    reference_title: "Fibroblasts derived from patients with opsismodysplasia display SHIP2-specific cell migration and adhesion defects."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "signaling events linked to migration and particularly to adhesion, which are lost in OPS patients, would prevent normal endochondral ossification."
    explanation: Links cell migration and adhesion defects to the skeletal phenotype.
- name: Renal phosphate wasting
  description: >
    A subset of patients develops renal phosphate wasting with elevated FGF23 levels,
    leading to hypophosphatemic rickets. Phosphate wasting is associated with more
    severe bone demineralization and a more severe overall phenotype. The mechanism
    linking SHIP2 loss to FGF23 elevation and renal phosphate handling is not fully
    understood.
  biological_processes:
  - preferred_term: Phosphate ion homeostasis
    term:
      id: GO:0055062
      label: phosphate ion homeostasis
    modifier: ABNORMAL
  evidence:
  - reference: PMID:17315533
    reference_title: "Hypophosphatemic rickets in opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We now demonstrate an association between opsismodysplasia, hypophosphatemic rickets, and FGF23 elevation."
    explanation: First report demonstrating the link between opsismodysplasia and FGF23-mediated phosphate wasting.
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Renal phosphate wasting is associated with severe bone demineralization and a more severe phenotype."
    explanation: Establishes that phosphate wasting worsens the skeletal phenotype.
phenotypes:
- name: Severe short stature
  category: Clinical
  description: >
    Marked linear growth impairment is a core manifestation of
    opsismodysplasia.
  phenotype_term:
    preferred_term: Severe short stature
    term:
      id: HP:0003510
      label: Severe short stature
  evidence:
  - reference: PMID:40620719
    reference_title: "Pamidronate Treatment of a Patient with Opsismodysplasia and a Novel INPPL1 Variant: Efficacy, Mechanism, and Clinical Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Initial evaluations showed severe short stature and low bone mineral density (DEXA SDS: -3.16)."
    explanation: Recent case evidence confirms severe short stature as a core phenotype.
- name: Micromelia
  category: Clinical
  description: >
    Extremely short limbs with disproportionate shortening, particularly of the
    hands and feet.
  phenotype_term:
    preferred_term: Micromelia
    term:
      id: HP:0002983
      label: Micromelia
  phenotype_contexts:
  - onset:
      onset_category: ANTENATAL
      notes: The landmark molecular series described limb shortening as pre- and postnatal.
    evidence:
    - reference: PMID:23273569
      reference_title: "Exome sequencing identifies INPPL1 mutations as a cause of opsismodysplasia."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Opsismodysplasia (OPS) is a severe autosomal-recessive chondrodysplasia characterized by pre- and postnatal micromelia with extremely short hands and feet."
      explanation: Directly supports antenatal onset of micromelia.
  evidence:
  - reference: PMID:23273569
    reference_title: "Exome sequencing identifies INPPL1 mutations as a cause of opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Opsismodysplasia (OPS) is a severe autosomal-recessive chondrodysplasia characterized by pre- and postnatal micromelia with extremely short hands and feet."
    explanation: Micromelia with short hands and feet is a defining feature.
- name: Severe platyspondyly
  category: Clinical
  description: >
    Flattened vertebral bodies are a consistent radiographic finding.
  phenotype_term:
    preferred_term: Severe platyspondyly
    term:
      id: HP:0004565
      label: Severe platyspondyly
  evidence:
  - reference: PMID:23273569
    reference_title: "Exome sequencing identifies INPPL1 mutations as a cause of opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main radiological features are severe platyspondyly, squared metacarpals, delayed skeletal ossification, and metaphyseal cupping."
    explanation: The landmark molecular cohort identifies severe platyspondyly as a main radiographic feature.
- name: Delayed skeletal maturation
  category: Clinical
  description: >
    Markedly delayed bone age with retarded ossification of epiphyses is a
    hallmark radiographic finding.
  phenotype_term:
    preferred_term: Delayed skeletal maturation
    term:
      id: HP:0002750
      label: Delayed skeletal maturation
  evidence:
  - reference: PMID:6496568
    reference_title: "Opsismodysplasia: a new type of chondrodysplasia with predominant involvement of the bones of the hand and the vertebrae."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "very retarded bone maturation; marked shortness of the bones of the hands and of the feet with concave metaphyses; and thin, lamellar vertebral bodies."
    explanation: Original disease description emphasizing delayed bone maturation as a cardinal feature.
- name: Metaphyseal cupping
  category: Clinical
  description: >
    Concave, cupped metaphyses of the long bones and tubular bones of the hands
    and feet are characteristic radiographic findings.
  phenotype_term:
    preferred_term: Metaphyseal cupping
    term:
      id: HP:0003021
      label: Metaphyseal cupping
  evidence:
  - reference: PMID:23273569
    reference_title: "Exome sequencing identifies INPPL1 mutations as a cause of opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main radiological features are severe platyspondyly, squared metacarpals, delayed skeletal ossification, and metaphyseal cupping."
    explanation: The defining molecular cohort lists metaphyseal cupping among the main radiographic abnormalities.
- name: Delayed epiphyseal ossification
  category: Clinical
  description: >
    Delayed mineralization and appearance of secondary ossification centers is a
    defining radiographic feature.
  phenotype_term:
    preferred_term: Delayed epiphyseal ossification
    term:
      id: HP:0002663
      label: Delayed epiphyseal ossification
  evidence:
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main radiological features are severe platyspondyly, short long bones including squared metacarpals, delayed epiphyseal ossification, and metaphyseal flaring and cupping (7–10)."
    explanation: This case-based review directly identifies delayed epiphyseal ossification as a core radiographic abnormality.
- name: Relative macrocephaly
  category: Clinical
  description: >
    Head circumference is relatively large compared to the shortened trunk and
    limbs, contributing to the characteristic craniofacial appearance.
  phenotype_term:
    preferred_term: Relative macrocephaly
    term:
      id: HP:0004482
      label: Relative macrocephaly
  evidence:
  - reference: PMID:39911177
    reference_title: "A Case of Opsismodysplasia with a Novel INPPL1 Variant."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
    explanation: Recent case evidence documents relative macrocephaly as part of the characteristic craniofacial gestalt.
- name: Large fontanelles
  category: Clinical
  description: >
    Delayed closure and persistent widening of the anterior fontanelle have been
    reported in surviving children.
  phenotype_term:
    preferred_term: Large fontanelles
    term:
      id: HP:0000239
      label: Large fontanelles
  evidence:
  - reference: PMID:24953221
    reference_title: "Opsismodysplasia resulting from an insertion mutation in the SH2 domain, which destabilizes INPPL1."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "She had wide open anterior fontanelles which closed at six years of age."
    explanation: This patient report shows persistent large fontanelles well beyond infancy.
- name: Frontal bossing
  category: Clinical
  description: Prominent forehead.
  phenotype_term:
    preferred_term: Frontal bossing
    term:
      id: HP:0002007
      label: Frontal bossing
  evidence:
  - reference: PMID:34094554
    reference_title: "Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Opsismodysplasia is an autosomal recessive osteochondrodysplasia disorders characterized by a severe delay in bone maturation. This leads to rhizomelic micromelia with small hands and feet, relative macrocephaly, and craniofacial dysmorphism including frontal bossing, short nose with anteverted nares and depressed nasal bridge, long philtrum, and abnormal ears."
    explanation: Prenatal imaging demonstrates frontal bossing in an affected fetus.
- name: Midface retrusion
  category: Clinical
  description: Underdevelopment of the midface structures.
  phenotype_term:
    preferred_term: Midface hypoplasia
    term:
      id: HP:0011800
      label: Midface retrusion
  evidence:
  - reference: PMID:39911177
    reference_title: "A Case of Opsismodysplasia with a Novel INPPL1 Variant."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
    explanation: The reported midface hypoplasia corresponds to the characteristic midfacial retrusion seen in opsismodysplasia.
- name: Depressed nasal bridge
  category: Clinical
  description: Flattened nasal bridge.
  phenotype_term:
    preferred_term: Depressed nasal bridge
    term:
      id: HP:0005280
      label: Depressed nasal bridge
  evidence:
  - reference: PMID:39911177
    reference_title: "A Case of Opsismodysplasia with a Novel INPPL1 Variant."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
    explanation: The depressed nasal bridge is explicitly reported in a recent molecularly confirmed case.
- name: Short nose
  category: Clinical
  description: Shortened nasal length.
  phenotype_term:
    preferred_term: Short nose
    term:
      id: HP:0003196
      label: Short nose
  evidence:
  - reference: PMID:34094554
    reference_title: "Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Examination of the newborn (case A) shows short limbs with small trident hands and feet, and craniofacial dysmorphism including hypertelorism, depressed nasal bridge, short nose with anteverted nares and depressed nasal bridge, long philtrum, and low set deformed ears."
    explanation: The postnatal examination in a molecularly confirmed newborn documents a short nose.
- name: Anteverted nares
  category: Clinical
  description: Upturned nostrils.
  phenotype_term:
    preferred_term: Anteverted nares
    term:
      id: HP:0000463
      label: Anteverted nares
  evidence:
  - reference: PMID:34094554
    reference_title: "Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Examination of the newborn (case A) shows short limbs with small trident hands and feet, and craniofacial dysmorphism including hypertelorism, depressed nasal bridge, short nose with anteverted nares and depressed nasal bridge, long philtrum, and low set deformed ears."
    explanation: The newborn examination explicitly reports anteverted nares.
- name: Long philtrum
  category: Clinical
  description: Increased distance between the nasal base and upper lip.
  phenotype_term:
    preferred_term: Long philtrum
    term:
      id: HP:0000343
      label: Long philtrum
  evidence:
  - reference: PMID:39911177
    reference_title: "A Case of Opsismodysplasia with a Novel INPPL1 Variant."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "He had dysmorphic findings including relative macrocephaly, midface hypoplasia, depressed nasal bridge, anteverted nostrils, long philtrum, small hands and feet, and brachydactyly."
    explanation: The long philtrum is part of the recurrent craniofacial phenotype.
- name: Bowing of the long bones
  category: Clinical
  description: Bowed long bones, particularly of the lower extremities.
  phenotype_term:
    preferred_term: Bowing of the long bones
    term:
      id: HP:0006487
      label: Bowing of the long bones
  evidence:
  - reference: PMID:27233067
    reference_title: "Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Radiographs of fetus #2 showed hydropic changes and short limbs with flaring and metaphyseal cupping were reported. Both distal femoral metaphyses appeared irregular and the radii, femora and tibae were bowed (Figure 1)."
    explanation: Prenatal radiographs in a severe familial case document bowing of multiple long bones.
- name: Flat acetabular roof
  category: Clinical
  description: >
    Pelvic radiographs can show horizontally oriented, dysplastic acetabular
    roofs.
  phenotype_term:
    preferred_term: Flat acetabular roof
    term:
      id: HP:0003180
      label: Flat acetabular roof
  evidence:
  - reference: PMID:27233067
    reference_title: "Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The iliac bones were decreased in vertical height with horizontal orientation of the acetabular roofs."
    explanation: This radiographic description directly supports a flat acetabular roof phenotype.
- name: Narrow chest
  category: Clinical
  description: >
    A small thorax is a recurrent prenatal and postnatal finding and likely
    contributes to respiratory compromise in severe cases.
  phenotype_term:
    preferred_term: Narrow chest
    term:
      id: HP:0000774
      label: Narrow chest
  evidence:
  - reference: PMID:34094554
    reference_title: "Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chest appears narrow and abdomen is protuberant."
    explanation: Prenatal imaging demonstrates a narrow thorax in severe opsismodysplasia.
- name: Scoliosis
  category: Clinical
  description: >
    Spinal curvature can develop in surviving children.
  phenotype_term:
    preferred_term: Scoliosis
    term:
      id: HP:0002650
      label: Scoliosis
  evidence:
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "She was identified to have scoliosis with a 42° right thoracic curve, and a 57° left lumbar curve."
    explanation: Detailed follow-up of a surviving child documents clinically significant scoliosis.
- name: Respiratory insufficiency
  category: Clinical
  description: >
    Respiratory compromise ranges from neonatal distress to progressive
    respiratory failure in more severe cases.
  phenotype_term:
    preferred_term: Respiratory insufficiency
    term:
      id: HP:0002093
      label: Respiratory insufficiency
  evidence:
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These cases provide evidence of the variability in severity of findings in siblings with opsismodysplasia and suggest that those with phosphate wasting have more severe skeletal findings and respiratory compromise."
    explanation: The sibling case report identifies respiratory compromise as a major clinical complication.
- name: Hypoplasia of the odontoid process
  category: Clinical
  description: >
    Craniocervical abnormalities can include odontoid hypoplasia, creating
    potential concern for cervical instability.
  phenotype_term:
    preferred_term: Hypoplasia of the odontoid process
    term:
      id: HP:0003311
      label: Hypoplasia of the odontoid process
  evidence:
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cervical spine films show odontoid hypoplasia, with no evidence of atlantoaxial or occipitocervical instability."
    explanation: Follow-up cervical imaging in a surviving child documented odontoid hypoplasia.
- name: Polyhydramnios
  category: Clinical
  description: >
    Polyhydramnios has been reported during affected pregnancies and can be an
    early prenatal clue.
  phenotype_term:
    preferred_term: Polyhydramnios
    term:
      id: HP:0001561
      label: Polyhydramnios
  evidence:
  - reference: PMID:20422326
    reference_title: "Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "During the antenatal period, polyhydramnios was noted."
    explanation: This neonatal case report documents polyhydramnios as a prenatal finding.
- name: Hydrocephalus
  category: Clinical
  description: >
    Hydrocephalus appears to be a rare associated finding rather than a core
    manifestation.
  phenotype_term:
    preferred_term: Hydrocephalus
    term:
      id: HP:0000238
      label: Hydrocephalus
  evidence:
  - reference: PMID:16473316
    reference_title: "A further case of opsismodysplasia with hydrocephalus."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "She also had hydrocephaly, a rare finding in opsismodysplasia."
    explanation: This report supports hydrocephalus as an uncommon but documented associated feature.
- name: Motor delay
  category: Clinical
  description: >
    Delayed motor development has been reported in some survivors, likely
    reflecting the severity of the skeletal disease.
  phenotype_term:
    preferred_term: Motor delay
    term:
      id: HP:0001270
      label: Motor delay
  evidence:
  - reference: PMID:24953221
    reference_title: "Opsismodysplasia resulting from an insertion mutation in the SH2 domain, which destabilizes INPPL1."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "She achieved neuromotor developmental milestones late."
    explanation: This long-term follow-up report documents delayed motor milestone acquisition.
- name: Hypophosphatemic rickets
  category: Clinical
  description: >
    A subset of patients develops renal phosphate wasting with elevated FGF23,
    leading to hypophosphatemic rickets and severe bone demineralization.
  phenotype_term:
    preferred_term: Hypophosphatemic rickets
    term:
      id: HP:0004912
      label: Hypophosphatemic rickets
  evidence:
  - reference: PMID:17315533
    reference_title: "Hypophosphatemic rickets in opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Both children had hypophosphatemia, decreased TRP, and rickets."
    explanation: Documents hypophosphatemic rickets in opsismodysplasia patients.
  - reference: PMID:17315533
    reference_title: "Hypophosphatemic rickets in opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We now demonstrate an association between opsismodysplasia, hypophosphatemic rickets, and FGF23 elevation."
    explanation: Establishes the association with FGF23-mediated phosphate wasting.
- name: Renal phosphate wasting
  category: Clinical
  description: >
    Renal phosphate wasting occurs in a subset of patients and can mark a more
    severe course with osteodystrophy.
  phenotype_term:
    preferred_term: Renal phosphate wasting
    term:
      id: HP:0000117
      label: Renal phosphate wasting
  evidence:
  - reference: PMID:23273567
    reference_title: "Whole-genome analysis reveals that mutations in inositol polyphosphate phosphatase-like 1 cause opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Opsismodysplasia is a rare, autosomal-recessive skeletal dysplasia characterized by short stature, characteristic facial features, and in some cases severe renal phosphate wasting."
    explanation: The gene discovery study identifies renal phosphate wasting as a clinically important subset phenotype.
- name: Reduced bone mineral density
  category: Clinical
  description: >
    Decreased bone mineralization, ranging from osteopenia to severe
    demineralization, particularly in patients with phosphate wasting.
  phenotype_term:
    preferred_term: Reduced bone mineral density
    term:
      id: HP:0004349
      label: Reduced bone mineral density
  evidence:
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Renal phosphate wasting is associated with severe bone demineralization and a more severe phenotype."
    explanation: Bone demineralization is a feature, exacerbated by phosphate wasting.
  - reference: PMID:40620719
    reference_title: "Pamidronate Treatment of a Patient with Opsismodysplasia and a Novel INPPL1 Variant: Efficacy, Mechanism, and Clinical Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Initial evaluations showed severe short stature and low bone mineral density (DEXA SDS: -3.16)."
    explanation: Recent case evidence shows reduced bone mineral density even without hypophosphatemic rickets.
- name: Short foot
  category: Clinical
  description: >
    Extremely short tubular bones of the feet with concave metaphyses.
  phenotype_term:
    preferred_term: Short foot
    term:
      id: HP:0001773
      label: Short foot
  evidence:
  - reference: PMID:6496568
    reference_title: "Opsismodysplasia: a new type of chondrodysplasia with predominant involvement of the bones of the hand and the vertebrae."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "very retarded bone maturation; marked shortness of the bones of the hands and of the feet with concave metaphyses; and thin, lamellar vertebral bodies."
    explanation: Short feet with concave metaphyses are defining features from the original description.
- name: Short metacarpal
  category: Clinical
  description: >
    Hand radiographs show striking shortening of the metacarpals and phalanges.
  phenotype_term:
    preferred_term: Short metacarpal
    term:
      id: HP:0010049
      label: Short metacarpal
  evidence:
  - reference: PMID:39911177
    reference_title: "A Case of Opsismodysplasia with a Novel INPPL1 Variant."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Delayed bone age, short metacarpals and phalanges, wide and irregular metaphysis, platyspondyly, anterior beaking of the vertebrae, T12 vertebral hypoplasia, and acetabular dysplasia were noted on X-rays."
    explanation: This recent molecularly confirmed case documents the characteristic marked shortening of the metacarpals.
genetic:
- name: INPPL1 biallelic variants
  gene_term:
    preferred_term: INPPL1
    term:
      id: hgnc:6080
      label: INPPL1
  association: Causative
  inheritance:
  - name: Autosomal recessive
    inheritance_term:
      preferred_term: Autosomal recessive inheritance
      term:
        id: HP:0000007
        label: Autosomal recessive inheritance
    evidence:
    - reference: PMID:40504975
      reference_title: "INPPL1-Related Opsismodysplasia."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "INPPL1-related opsismodysplasia is inherited in an autosomal recessive manner."
      explanation: GeneReviews summarizes the Mendelian inheritance pattern for biallelic INPPL1-related disease.
  notes: >
    Over 25 distinct mutations have been identified across more than 20 families,
    including nonsense, frameshift, missense, and splice-site variants. Most
    pathogenic missense variants affect the catalytic 5-phosphatase domain.
    Frameshift variants appear associated with lethal outcomes. Schneckenbecken
    dysplasia is an allelic disorder with a uniformly lethal phenotype. INPPL1
    mutations explain approximately 60% of clinically diagnosed cases; the genetic
    basis of the remaining clinically diagnosed cases remains unresolved, so
    INPPL1-related wording should be reserved for molecularly confirmed disease.
  evidence:
  - reference: PMID:23273569
    reference_title: "Exome sequencing identifies INPPL1 mutations as a cause of opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Opsismodysplasia (OPS) is a severe autosomal-recessive chondrodysplasia characterized by pre- and postnatal micromelia with extremely short hands and feet."
    explanation: Landmark study identifying INPPL1 mutations as the cause of opsismodysplasia.
  - reference: PMID:23273567
    reference_title: "Whole-genome analysis reveals that mutations in inositol polyphosphate phosphatase-like 1 cause opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "INPPL1 mutations explain ~60% of cases overall, including both of the families in our cohort with more than one affected child and 50% of the simplex cases."
    explanation: Estimates the proportion of clinically diagnosed cases attributable to INPPL1 mutations.
  - reference: PMID:34094554
    reference_title: "Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Schneckenbecken dysplasia and Opsismodysplasia are allelic disorders caused by pathogenic variants in INPPL1 gene with lethal outcomes in Schneckenbecken dysplasia and nonlethal prognosis in Opsismodysplasia."
    explanation: Establishes the allelic relationship with Schneckenbecken dysplasia.
  - reference: PMID:34094554
    reference_title: "Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Prediction of lethality is difficult to determine in prenatal‐onset skeletal dysplasia especially with borderline lethality indices measured in prenatal ultrasound."
    explanation: Highlights the challenge of predicting lethal versus nonlethal outcomes in prenatal INPPL1-related skeletal dysplasia.
animal_models:
- species: Mouse
  genotype: Inppl1 catalytic knock-out
  description: >
    An INPPL1 catalytic knock-out mouse model recapitulates the opsismodysplasia
    phenotype with growth plate defects, altered chondrocyte differentiation, and
    impaired matrix mineralization. Elevated MEK-Erk1/2 signaling was identified
    in SHIP2-inactivated chondrocytes. Treatment with a MEK inhibitor partially
    rescued mineralization defects and hypertrophic zone size, identifying MEK-Erk1/2
    as a potential therapeutic target.
  genes:
  - preferred_term: Inppl1
    term:
      id: hgnc:6080
      label: INPPL1
  evidence:
  - reference: PMID:31519471
    reference_title: "Altered chondrocyte differentiation, matrix mineralization and MEK-Erk1/2 signaling in an INPPL1 catalytic knock-out mouse model of opsismodysplasia."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Opsismodysplasia (OPS) is a rare but severe autosomal recessive skeletal chondrodysplasia caused by inactivating mutations in the Inppl1/Ship2 gene."
    explanation: Describes the INPPL1 catalytic knock-out mouse model of opsismodysplasia.
  - reference: PMID:31519471
    reference_title: "Altered chondrocyte differentiation, matrix mineralization and MEK-Erk1/2 signaling in an INPPL1 catalytic knock-out mouse model of opsismodysplasia."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Treatment of chondrocytes and bones in culture with a MEK inhibitor partially rescued the production of mineralized nodules, the size of the hypertrophic chondrocyte zone and bone growth, raising the possibility of a treatment that could partially reduce the phenotype of this severe condition."
    explanation: MEK inhibition partially rescues the skeletal phenotype in the mouse model.
- species: Zebrafish
  genotype: inppl1a mutant
  description: >
    Zebrafish inppl1a mutants are shorter from early larval stages and develop
    notochord curvatures, thoracic scoliosis, and vertebral malformations.
    The model demonstrates that inppl1a-dependent vacuolated cell expansion is
    essential for normal notochord mechanics, spine morphogenesis, and
    endochondral bone lengthening, providing conserved organismal support for
    INPPL1-related skeletal pathophysiology.
  genes:
  - preferred_term: inppl1a
    term:
      id: hgnc:6080
      label: INPPL1
  evidence:
  - reference: PMID:40209709
    reference_title: "Cell expansion for notochord mechanics and endochondral bone lengthening in zebrafish depends on the 5'-inositol phosphatase Inppl1a."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "We demonstrate that inppl1a-dependent vacuolated cell expansion is essential to establish normal mechanical properties of the notochord and to facilitate the development of a straight spine."
    explanation: Zebrafish model demonstrates conserved role of INPPL1 in spine morphogenesis and endochondral bone lengthening.
diagnosis:
- name: Clinical and Radiographic Recognition
  description: >-
    Suspect INPPL1-related opsismodysplasia when prenatal-onset short stature,
    short bowed limbs, characteristic craniofacial features, narrow thorax,
    small hands and feet, delayed epiphyseal mineralization, metaphyseal cupping,
    and platyspondyly form the clinical and radiographic pattern. Skeletal
    survey or targeted radiographs establish this pattern and prioritize
    molecular confirmation.
  diagnosis_term:
    preferred_term: clinical imaging procedure
    term:
      id: MAXO:0000005
      label: clinical imaging procedure
  evidence:
  - reference: PMID:40504975
    reference_title: "INPPL1-Related Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      INPPL1-related opsismodysplasia is characterized by prenatal-onset short
      stature, short, bowed limbs, characteristic facial features (relative
      macrocephaly, prominent forehead, midface retrusion, depressed nasal
      bridge, short nose, anteverted nares, relatively long philtrum), narrow
      thorax, small hands and feet, delayed epiphyseal mineralization,
      metaphyseal cupping, and platyspondyly.
    explanation: >-
      GeneReviews summarizes the core clinical and radiographic pattern that
      should trigger diagnostic consideration.
- name: Molecular Confirmation of Biallelic INPPL1 Pathogenic Variants
  description: >-
    Molecular genetic testing confirms INPPL1-related opsismodysplasia by
    identifying biallelic pathogenic variants in INPPL1. Because INPPL1 explains
    only a subset of clinically diagnosed cases, negative INPPL1 testing should
    prompt broader skeletal dysplasia evaluation rather than excluding the
    clinical diagnosis outright.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: MAXO:0000533
      label: molecular genetic testing
  evidence:
  - reference: PMID:40504975
    reference_title: "INPPL1-Related Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The diagnosis of INPPL1-related opsismodysplasia is established in a proband with characteristic clinical and radiographic features and biallelic pathogenic variants in INPPL1 identified by molecular genetic testing."
    explanation: >-
      GeneReviews defines the biallelic INPPL1 molecular confirmation criterion
      for INPPL1-related opsismodysplasia.
  - reference: PMID:23273567
    reference_title: "Whole-genome analysis reveals that mutations in inositol polyphosphate phosphatase-like 1 cause opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "INPPL1 mutations explain ~60% of cases overall, including both of the families in our cohort with more than one affected child and 50% of the simplex cases."
    explanation: >-
      This supports preserving a distinction between clinically diagnosed
      opsismodysplasia and the INPPL1-confirmed subset.
- name: INPPL1 Spectrum Differential Diagnosis
  description: >-
    Diagnostic interpretation should explicitly distinguish INPPL1-related
    opsismodysplasia from Schneckenbecken dysplasia, the allelic lethal skeletal
    dysplasia, and from other spondylodysplastic dysplasias in INPPL1-negative
    clinically diagnosed cases.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: MAXO:0000533
      label: molecular genetic testing
  evidence:
  - reference: PMID:34094554
    reference_title: "Prenatal-onset INPPL1-related skeletal dysplasia in two unrelated families: Diagnosis and prediction of lethality."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Schneckenbecken dysplasia and Opsismodysplasia are allelic disorders caused by pathogenic variants in INPPL1 gene with lethal outcomes in Schneckenbecken dysplasia and nonlethal prognosis in Opsismodysplasia."
    explanation: >-
      This establishes the key allelic differential and the lethal versus
      nonlethal boundary within INPPL1-related skeletal dysplasia.
treatments:
- name: Bisphosphonate therapy
  description: >
    Intravenous pamidronate has improved bone mineral density and gross motor
    function in patients with opsismodysplasia. Treatment benefit has been
    demonstrated both in patients with and without hypophosphatemic rickets.
  treatment_term:
    preferred_term: bisphosphonate agent therapy
    term:
      id: MAXO:0000954
      label: bisphosphonate agent therapy
  evidence:
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This report represents the first described cases of opsismodysplasia treated with intravenous bisphosphonate (pamidronate)."
    explanation: First report of bisphosphonate use in opsismodysplasia.
  - reference: PMID:26157786
    reference_title: "Opsismodysplasia: Phosphate Wasting Osteodystrophy Responds to Bisphosphonate Therapy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "At 10 years of age, he has stopped taking his wheelchair to school and runs during recess, demonstrating a remarkable progress presumably related to his pamidronate usage."
    explanation: Demonstrates functional motor improvement with bisphosphonate therapy.
  - reference: PMID:40504975
    reference_title: "INPPL1-Related Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Intravenous bisphosphonate therapy has improved bone mineral density and gross motor function in two individuals with INPPL1-related opsismodysplasia."
    explanation: GeneReviews confirms bisphosphonate benefit for bone density and motor function.
  - reference: PMID:40620719
    reference_title: "Pamidronate Treatment of a Patient with Opsismodysplasia and a Novel INPPL1 Variant: Efficacy, Mechanism, and Clinical Outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Pamidronate is effective in treating OPS even in the absence of hypophosphatemic rickets, showing potential as a therapeutic option for this rare condition."
    explanation: Demonstrates efficacy of pamidronate even without phosphate wasting.
- name: Phosphate and calcitriol supplementation
  description: >
    Oral phosphorus and calcitriol supplementation for patients with renal
    phosphate wasting and hypophosphatemic rickets.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:17315533
    reference_title: "Hypophosphatemic rickets in opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Oral phosphorus and calcitriol improved metaphyseal mineralization, yet serum phosphate levels remained relatively low and renal phosphate wasting persisted."
    explanation: Directly documents the treatment response to phosphate and calcitriol supplementation.
- name: Multidisciplinary Surveillance and Supportive Care
  description: >
    Longitudinal supportive care monitors and manages fracture risk, cervical
    spine instability or cord compression, scoliosis, respiratory insufficiency
    or sleep apnea, swallowing and feeding issues, delayed gross motor skills,
    bone demineralization, and renal phosphate wasting. Care is coordinated
    across skeletal-dysplasia orthopedics/neurosurgery, endocrinology,
    pulmonology, rehabilitation medicine, physical therapy, occupational therapy,
    and other specialists as indicated.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  evidence:
  - reference: PMID:40504975
    reference_title: "INPPL1-Related Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Complications include increased risk of fractures, cervical spine abnormalities, scoliosis, bone pain, respiratory issues, and delayed gross motor skills."
    explanation: >-
      GeneReviews identifies the longitudinal complication targets for
      supportive care and surveillance.
  - reference: PMID:40504975
    reference_title: "INPPL1-Related Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cervical spine complications should be managed by specialists familiar with skeletal dysplasias involving the spine including an orthopedist and neurosurgeon; surgical stabilization should be performed to prevent progressive myelopathy"
    explanation: >-
      This supports specialist cervical-spine surveillance and escalation to
      surgical stabilization when progressive myelopathy risk is present.
  - reference: PMID:40504975
    reference_title: "INPPL1-Related Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Clinical examination for scoliosis every six to 12 months with radiographs
      when indicated; endocrinology evaluation for hypophosphatemia and renal
      phosphate wasting every six to 12 months and when indicated
    explanation: >-
      GeneReviews provides frequency guidance for scoliosis and renal-phosphate
      surveillance.
  - reference: PMID:40504975
    reference_title: "INPPL1-Related Opsismodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      pulmonary function studies, chest radiographs, swallowing evaluation, and
      sleep study every six to 12 months and when indicated per pulmonologist;
      swallowing evaluation as indicated to evaluate for aspiration;
      developmental assessment to assess gross motor skills annually or as
      needed; rehabilitation medicine, physical therapy, and occupational
      therapy consultations when indicated
    explanation: >-
      This supports respiratory, swallowing, developmental, rehabilitation, and
      therapy surveillance as part of supportive management.
datasets:
references:
- reference: PMID:40504975
  title: "INPPL1-Related Opsismodysplasia."
  tags:
  - GeneReviews
  findings: []
📚

References & Deep Research

References

1
INPPL1-Related Opsismodysplasia.
No top-level findings curated for this source.

Deep Research

1
Falcon
Disease Pathophysiology Research Template
Edison Scientific Literature 22 citations 2026-04-02T22:48:35.269690

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Pathophysiology Research Template

Target Disease

  • Disease Name: Opsismodysplasia
  • MONDO ID: (if available)
  • Category: Mendelian

Research Objectives

Please provide a comprehensive research report on the pathophysiology of Opsismodysplasia. Focus on the molecular and cellular mechanisms underlying disease progression.

Required Information

1. Core Pathophysiology

  • What are the primary pathophysiological mechanisms?
  • What molecular pathways are dysregulated?
  • What cellular processes are affected?

2. Key Molecular Players

  • Genes/Proteins: Which genes are causally involved or implicated?
  • Chemical Entities: What metabolites, drugs, or small molecules are relevant?
  • Cell Types: Which cell types are primarily affected?
  • Anatomical Locations: Which tissues/organs are involved?

3. Biological Processes (for GO annotation)

  • What biological processes (GO terms) are disrupted?
  • Consider: signaling pathways, metabolic processes, cellular responses, transport, etc.

4. Cellular Components

  • Where in the cell do key processes occur?
  • Consider: organelles, membrane compartments, extracellular space, etc.

5. Disease Progression

  • What is the sequence of events from initial trigger to clinical manifestation?
  • Are there distinct stages or phases?

6. Phenotypic Manifestations

  • What are the key clinical phenotypes?
  • How do they relate to the underlying mechanisms?

Citation Requirements

  • Cite primary literature (PMID preferred) for all mechanistic claims
  • Prioritize recent reviews and landmark papers
  • Include direct quotes where possible to support key statements

Output Format

Structure your response as a narrative that could be used to populate a disease knowledge base entry with: - Pathophysiology description - Gene/protein annotations with ontology terms (HGNC, GO) - Phenotype associations (HP terms) - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Evidence items with PMIDs

Comprehensive Research Report: Opsismodysplasia (OPSMD)

0. Disease identifiers and overview

Opsismodysplasia is a rare Mendelian skeletal dysplasia characterized by delayed skeletal maturation and severe abnormalities of endochondral bone growth. An authoritative recent review describes opsismodysplasia as a skeletal dysplasia “primarily characterized by the delayed ossification of maturing bones.” (muller2024thefunctionalroles pages 14-15)

  • MONDO disease ID: MONDO:0009785 (Open Targets disease entity; retrieved via Open Targets association for OPSMD–INPPL1). (below2013wholegenomeanalysisreveals pages 5-7)
  • Inheritance: Autosomal recessive (biallelic pathogenic variants). (below2013wholegenomeanalysisreveals pages 5-7, celine2013exomesequencingidentifies pages 1-2)
  • Primary causal gene: INPPL1 (HGNC:6091), encoding SHIP2 (Src homology 2 domain-containing inositol 5-phosphatase 2). (below2013wholegenomeanalysisreveals pages 5-7, celine2013exomesequencingidentifies pages 1-2)

1. Key concepts and definitions (current understanding)

1.1 Core molecular definition

INPPL1/SHIP2 is a phosphoinositide 5-phosphatase that acts within the PI3K signaling network by turning over phosphatidylinositol lipids. One report summarizes SHIP2 as dephosphorylating the “lipid second messenger phosphoinositol (3,4,5)P3,” consistent with its canonical role in terminating or reshaping PI3K signaling outputs. (feist2016novelcompoundheterozygous pages 3-4)

In the discovery-era clinical genetics literature, INPPL1 is placed in the PI3K lipid-signaling axis: PI3K produces PtdIns(3,4,5)P3, which can be converted by 5-phosphatases (including SHIP2) to PtdIns(3,4)P2. (celine2013exomesequencingidentifies pages 4-4)

1.2 Pathophysiologic definition at the tissue level

Opsismodysplasia is best conceptualized as a disorder of growth plate architecture and endochondral ossification.

Growth plate histopathology in opsismodysplasia demonstrates: - Loss of normal proliferative-zone organization (columnar arrangement) - Reduction of the hypertrophic zone and fewer hypertrophic chondrocytes

These features were explicitly reported in the initial AJHG cohort, indicating that the molecular defect produces a characteristic cellular disorganization of the growth plate that plausibly explains delayed epiphyseal ossification and skeletal shortening. (celine2013exomesequencingidentifies pages 1-2)

2. Core pathophysiology

2.1 Primary mechanisms

Primary pathophysiological mechanism: biallelic INPPL1 loss-of-function (or destabilizing) variants lead to dysregulated phosphoinositide metabolism and signaling, producing growth plate disorganization, impaired chondrocyte maturation, and delayed endochondral ossification.

Evidence supporting a loss-of-function mechanism includes mutation spectrum and protein loss: - In one AJHG series, most variants were truncating or splice-site, with missense variants clustering in the catalytic 5-phosphatase domain, consistent with disrupted enzymatic function. (celine2013exomesequencingidentifies pages 4-4, celine2013exomesequencingidentifies pages 1-2) - A fetal opsismodysplasia family showed no detectable SHIP2 protein in affected amniocytes, providing direct protein-level support for functional loss. (feist2016novelcompoundheterozygous pages 3-4, feist2016novelcompoundheterozygous media 56a554cb)

2.2 Dysregulated pathways

(a) Phosphoinositide metabolism / PI3K signaling - INPPL1/SHIP2 regulates PIP species (e.g., turnover of PtdIns(3,4,5)P3 and production of PtdIns(3,4)P2), which are second messengers organizing signaling and membrane–cytoskeleton processes. (celine2013exomesequencingidentifies pages 4-4, feist2016novelcompoundheterozygous pages 3-4) - A 2024 review provides functional context: SHIP2 activation reduces plasma membrane PtdIns(3,4,5)P3 and thereby inhibits AKT signaling, supporting a mechanistic link to PI3K–AKT output modulation. (muller2024thefunctionalroles pages 14-15)

(b) PI(3,4)P2-centered signaling as a mechanistic emphasis A mechanistic review highlighted that phenotypes in catalytically inactive SHIP2 models were attributed more to the lack of PI(3,4)P2 than to simplistic “hyperactive PI3K–Akt signaling,” suggesting that loss of specific phosphoinositide species (and their binding partners) may be central to developmental phenotypes. (edimo2014ship2signalingin pages 3-5)

(c) Developmental growth-factor signaling (FGF) connections (model-organism evidence) Zebrafish Ship2 knockdown perturbs outputs of FGF signaling (reported as dorsal fate expansion in early embryogenesis), supporting the plausibility that SHIP2-dependent phosphoinositide changes can rewire growth-factor pathway responses during development. (celine2013exomesequencingidentifies pages 4-6, edimo2014ship2signalingin pages 3-5)

2.3 Cellular processes affected

Key cellular processes implicated by human pathology and SHIP2 biology include: - Chondrocyte proliferation/organization (loss of columnar organization in proliferative zone) (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2) - Chondrocyte hypertrophy/differentiation (reduced hypertrophic zone, fewer hypertrophic chondrocytes) (celine2013exomesequencingidentifies pages 1-2) - Cell expansion/size regulation and tissue mechanics (recent zebrafish evidence—see below) (voigt2024aconservedregulation pages 1-3)

3. Key molecular players

3.1 Genes/proteins

  • INPPL1 (SHIP2) is the established causal gene/protein. (below2013wholegenomeanalysisreveals pages 5-7, celine2013exomesequencingidentifies pages 1-2)
  • Reported disease-associated SHIP2 variants listed in a 2024 review include R401W, P659S, W688C, F722I (illustrating variant distribution beyond truncations). (muller2024thefunctionalroles pages 14-15)

Statistics (genetic contribution): In a cohort analyzed by whole-genome methods, INPPL1 mutations explained 7/12 kindreds (58%) and 5/10 simplex cases (50%), supporting genetic heterogeneity but also highlighting INPPL1 as a major contributor among clinically diagnosed cases. (below2013wholegenomeanalysisreveals pages 5-7)

3.2 Chemical entities (metabolites and small molecules)

Endogenous phosphoinositides - Phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3)—substrate/regulated lipid messenger in SHIP2 pathway context. (celine2013exomesequencingidentifies pages 4-4, feist2016novelcompoundheterozygous pages 3-4) - Phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2)—product emphasized as mechanistically important in SHIP2-deficiency phenotypes. (edimo2014ship2signalingin pages 3-5)

Research/therapeutic probes (not established OPSMD therapies) A 2024 review describes SHIP2-selective inhibition (AS1949490) as increasing insulin-induced AKT phosphorylation and improving glycemic phenotypes in diabetic mouse models, reflecting active translational pharmacology around SHIP2. These compounds are best viewed as mechanistic tools and potential future repurposing leads rather than current opsismodysplasia therapies. (muller2024thefunctionalroles pages 14-15)

3.3 Cell types

The disease-relevant cell types are growth plate chondrocytes: - Proliferative chondrocytes (loss of columnar arrangement) (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2) - Hypertrophic chondrocytes (reduced hypertrophic zone) (celine2013exomesequencingidentifies pages 1-2)

3.4 Anatomical locations / tissues

Primary tissues involved: - Growth plate cartilage (histologic disorganization) (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2) - Epiphyses (delayed ossification), vertebrae (platyspondyly), pelvis/acetabulum, long bones (radiographic manifestations) (below2013wholegenomeanalysisreveals pages 5-7, li2014opsismodysplasiaresultingfrom pages 1-3)

4. Biological processes disrupted (GO-oriented)

Evidence-supported GO-relevant processes include: - Endochondral ossification (delayed epiphyseal ossification; growth plate disruption) (celine2013exomesequencingidentifies pages 1-2, muller2024thefunctionalroles pages 14-15) - Chondrocyte differentiation and hypertrophy (reduced hypertrophic zone) (celine2013exomesequencingidentifies pages 1-2) - Chondrocyte proliferation/organization (disorganized proliferative zone; absent columnar organization) (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2) - Phosphoinositide metabolic process / phosphatidylinositol dephosphorylation (SHIP2 enzymatic function; mutation localization to catalytic domain) (celine2013exomesequencingidentifies pages 4-4, edimo2014ship2signalingin pages 3-5) - Regulation of AKT signaling (SHIP2 reduces membrane PIP3 and inhibits AKT signaling in reviewed contexts) (muller2024thefunctionalroles pages 14-15) - FGF signaling modulation (zebrafish knockdown evidence) (edimo2014ship2signalingin pages 3-5)

5. Cellular components (where key processes occur)

Opsismodysplasia mechanisms localize to compartments where SHIP2 acts on phosphoinositides: - Plasma membrane: phosphoinositide substrates and PI3K signaling lipids (PIP3/PIP2) are membrane-associated; SHIP2 activity affects membrane PIP3 and AKT signaling output. (muller2024thefunctionalroles pages 14-15) - Cytosolic signaling complexes / docking interactions: INPPL1 has described non-catalytic scaffold/docking roles interacting with cytoskeletal and receptor-associated proteins, potentially relevant to organized growth plate column formation. (celine2013exomesequencingidentifies pages 4-6)

6. Disease progression model (sequence from trigger to phenotype)

  1. Initiating trigger: Biallelic pathogenic variants in INPPL1 (often truncating/splice or catalytic missense) produce SHIP2 loss or dysfunction. (below2013wholegenomeanalysisreveals pages 5-7, celine2013exomesequencingidentifies pages 1-2)
  2. Molecular consequence: Impaired phosphoinositide turnover (PtdIns(3,4,5)P3 → PtdIns(3,4)P2) and altered downstream signaling outputs (including PI3K–AKT modulation and potentially growth factor pathways such as FGF, per zebrafish data). (celine2013exomesequencingidentifies pages 4-4, edimo2014ship2signalingin pages 3-5)
  3. Cellular consequence in growth plate: Proliferative chondrocytes lose normal columnar organization; hypertrophic zone is reduced with fewer hypertrophic chondrocytes. (celine2013exomesequencingidentifies pages 1-2)
  4. Tissue consequence: Impaired endochondral ossification manifests as delayed epiphyseal ossification and poor mineralization with characteristic skeletal radiology (e.g., platyspondyly). (below2013wholegenomeanalysisreveals pages 5-7, li2014opsismodysplasiaresultingfrom pages 1-3)
  5. Organism-level outcomes: Severe short stature/micromelia; spinal deformity (scoliosis); thoracic restriction can contribute to pulmonary hypoplasia/respiratory insufficiency in severe cases. (celine2013exomesequencingidentifies pages 4-4)

Recent in vivo reinforcement (2024): Zebrafish inppl1a mutants are shorter from early larval stages and later develop notochord/spine abnormalities (thoracic scoliosis, vertebral malformations), supporting a conserved role in axial growth and endochondral lengthening. (voigt2024aconservedregulation pages 1-3)

7. Phenotypic manifestations (HP-oriented) and mechanistic links

Key clinical/radiographic phenotypes include: - Severe short stature and micromelia—consistent with impaired growth plate function and endochondral bone formation. (celine2013exomesequencingidentifies pages 4-4, celine2013exomesequencingidentifies pages 1-2) - Delayed epiphyseal and carpal ossification—directly matches the disease definition and endochondral ossification defect. (muller2024thefunctionalroles pages 14-15, li2014opsismodysplasiaresultingfrom pages 1-3) - Platyspondyly and skeletal undermineralization—consistent with defective ossification/mineralization. (below2013wholegenomeanalysisreveals pages 5-7, li2014opsismodysplasiaresultingfrom pages 1-3) - Scoliosis—reported clinically and supported by zebrafish model axial curvature. (celine2013exomesequencingidentifies pages 4-4, voigt2024aconservedregulation pages 1-3) - Narrow thorax / pulmonary hypoplasia in severe prenatal/perinatal cases—likely secondary to shortened ribs/vertebral anomalies and restricted thoracic development. (celine2013exomesequencingidentifies pages 4-4) - Low bone density and renal phosphate wasting have been described in an INPPL1-mutant case, suggesting that mineral metabolism abnormalities may modify skeletal outcomes in some patients. (li2014opsismodysplasiaresultingfrom pages 1-3)

8. Recent developments and latest research (prioritizing 2023–2024)

8.1 2024 SHIP2 disease-mechanism and pharmacology synthesis

A 2024 review consolidates SHIP2’s roles across human diseases and explicitly includes opsismodysplasia as an INPPL1/SHIP2-mutation disorder defined by delayed ossification. It also connects SHIP2 enzymology to AKT signaling modulation and summarizes pharmacologic tool compounds (e.g., AS1949490) demonstrating that SHIP2 is chemically tractable. (muller2024thefunctionalroles pages 14-15)

8.2 2024 organismal mechanism work relevant to skeletal growth

A 2024 zebrafish preprint provides new in vivo evidence that INPPL1 ortholog activity is required for cell expansion, notochord mechanics, spine morphogenesis, and endochondral bone lengthening—directly relevant to how opsismodysplasia could arise from altered cell/tissue growth mechanics in developing skeletal structures. (voigt2024aconservedregulation pages 1-3)

9. Current applications and real-world implementations

9.1 Clinical implementation: molecular diagnosis and counseling

Real-world implementation is primarily through genetic testing (exome/genome sequencing) for INPPL1 variants in suspected skeletal dysplasia cases. Early discovery work established that biallelic INPPL1 variants can be found across multiple unrelated families, supporting INPPL1 as a key diagnostic target. (celine2013exomesequencingidentifies pages 1-2)

9.2 Supportive management (example of mineral metabolism intervention)

A 2014 clinical report described renal phosphate wasting and very low bone density in an affected individual; phosphate replacement improved ambulation and dental eruption, and pamidronate was administered for low bone mineral density. This illustrates that while no disease-modifying therapy for the core signaling defect exists, targeted supportive interventions may improve function in selected patients. (li2014opsismodysplasiaresultingfrom pages 1-3)

10. Expert opinions and analysis (authoritative synthesis)

  • Primary conceptual model: opsismodysplasia is a growth-plate/endocondral-ossification disorder caused by disruption of phosphoinositide signaling via SHIP2 loss-of-function. This is supported by the convergence of (i) mutation patterns that abolish catalytic function, (ii) direct protein loss in patient-derived cells, and (iii) consistent growth plate disorganization. (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2, feist2016novelcompoundheterozygous media 56a554cb)
  • Mechanistic nuance: synthesis work highlights that SHIP2 biology may not reduce to “more AKT signaling”; rather, specific depletion of PI(3,4)P2 (and its effector interactions) may drive developmental phenotypes, which could explain why pathway readouts may differ across tissues and models. (edimo2014ship2signalingin pages 3-5)
  • Translational interpretation: 2024 reviews show SHIP2 is chemically targetable with inhibitors developed for metabolic/neuroinflammatory indications; however, because opsismodysplasia reflects developmental skeletal patterning and growth plate architecture, any future translation would likely require careful timing and tissue targeting, and is not currently established. (muller2024thefunctionalroles pages 14-15)

11. Evidence figure (protein-level evidence)

A key experimental/clinical evidence item is an immunoblot showing absence of SHIP2 protein in proband amniocytes (with α-tubulin loading control), supporting a loss-of-protein mechanism in at least some genotypes. (feist2016novelcompoundheterozygous media 56a554cb)

12. Evidence tables for knowledge-base population

Below are curated tables intended for direct knowledge-base population.

Concept/Mechanism Molecular players (gene/protein/lipid) Tissue/cell type Key evidence (brief) PMID/DOI Publication year URL
Causal genetic mechanism and growth-plate disorganization INPPL1 / SHIP2; phosphoinositides Growth plate cartilage; proliferative and hypertrophic chondrocytes Exome sequencing identified 12 distinct INPPL1 mutations in 10 unrelated families with opsismodysplasia; histology showed loss of normal columnar arrangement of proliferative chondrocytes, reduced hypertrophic zone, and fewer hypertrophic chondrocytes, supporting a primary defect in endochondral ossification (celine2013exomesequencingidentifies pages 1-2) DOI: 10.1016/j.ajhg.2012.11.015 2013 https://doi.org/10.1016/j.ajhg.2012.11.015
Proportion of cases explained by INPPL1 and supportive animal phenotype INPPL1 / SHIP2 Human skeleton; mouse axial/appendicular skeleton Whole-genome analysis found INPPL1 mutations in 7/12 kindreds (58%) and 5/10 simplex cases (50%); truncating variants predicted loss of function. Mouse SHIP2-null/catalytic-dead models showed diminished growth, shortened facial profile, and body size reduction, supporting a developmental role for SHIP2 in skeletal growth (below2013wholegenomeanalysisreveals pages 5-7) DOI: 10.1016/j.ajhg.2012.11.011 2013 https://doi.org/10.1016/j.ajhg.2012.11.011
Dysregulated phosphoinositide signaling and developmental pathway links SHIP2; PI(3,4,5)P3, PI(3,4)P2; FGF signaling Developing embryo; growth-related tissues Review synthesis: SHIP2 loss reduces PI(3,4)P2 and perturbs phosphoinositide balance; phenotypes in catalytic-dead mice were attributed more to lack of PI(3,4)P2 than simple PI3K-AKT hyperactivation. In zebrafish, Ship2 knockdown perturbed FGF signaling and expanded dorsal fates, linking SHIP2 to developmental patterning mechanisms relevant to OPS (edimo2014ship2signalingin pages 3-5) DOI: 10.1016/j.jbior.2013.09.002 2014 https://doi.org/10.1016/j.jbior.2013.09.002
Loss of SHIP2 protein and severe fetal growth-plate histopathology INPPL1 / SHIP2; PIP3 Fetal growth plate cartilage; amniocytes Compound-heterozygous INPPL1 variants were associated with absence of detectable SHIP2 protein in fetal cells. Fetal growth plate cartilage showed disorganized proliferative zones with near absent columnar organization, correlating with delayed epiphyseal ossification and severe platyspondyly (feist2016novelcompoundheterozygous pages 3-4) DOI: 10.1097/MCD.0000000000000136 2016 https://doi.org/10.1097/MCD.0000000000000136
Current disease definition and therapeutic context INPPL1 / SHIP2; PtdIns(3,4,5)P3; AKT; SHIP2 inhibitors AS1949490, K118, K149, K161 Skeletal tissue (disease context); broader cell signaling systems 2024 review defines opsismodysplasia as a skeletal dysplasia “primarily characterized by the delayed ossification of maturing bones.” It places SHIP2 in PIP3-to-AKT regulation and notes selective/pan-SHIP inhibitors (e.g., AS1949490, K161) with experimental activity in other disease settings, highlighting translational relevance even though no OPS-targeted therapy is established (muller2024thefunctionalroles pages 14-15) DOI: 10.3390/ijms25105254 2024 https://doi.org/10.3390/ijms25105254
Recent in vivo model for cell expansion, spine morphogenesis, and endochondral lengthening Zebrafish inppl1a (ortholog of INPPL1/SHIP2) Notochord vacuolated cells; spine; endochondral bone 2024 zebrafish preprint shows inppl1a is required for cell expansion, normal notochord mechanics, spine morphogenesis, and endochondral bone lengthening. Homozygous mutants were shorter, had reduced viability, notochord curvatures, adult thoracic scoliosis, and vertebral malformations, providing recent organismal support for INPPL1-related skeletal pathophysiology (voigt2024aconservedregulation pages 1-3) DOI: 10.1101/2024.08.12.607640 2024 https://doi.org/10.1101/2024.08.12.607640

Table: This table compiles the main mechanistic and experimental evidence linking INPPL1/SHIP2 dysfunction to opsismodysplasia, spanning discovery genetics, phosphoinositide signaling, growth-plate pathology, and recent model-organism work. It is useful as a concise evidence map for disease knowledge-base curation.

Entity type Preferred label ID (HGNC/GO/HP/CL/UBERON/CHEBI) Evidence/notes
Gene INPPL1 HGNC:6091 Causal gene for opsismodysplasia; encodes SHIP2, a phosphoinositide 5-phosphatase. Biallelic variants are predominantly truncating, splice-site, or catalytic-domain missense, consistent with loss of function; one cohort found INPPL1 variants in 7/12 kindreds (58%) and 5/10 simplex cases (below2013wholegenomeanalysisreveals pages 5-7, celine2013exomesequencingidentifies pages 1-2).
Gene SHIP2 protein UniProt/Q9Y5R2 Protein product of INPPL1; absent in affected fetal cells/amniocytes in one family, supporting pathogenic protein loss (feist2016novelcompoundheterozygous pages 3-4, feist2016novelcompoundheterozygous media 56a554cb).
GO phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity GO:0046856 SHIP2 dephosphorylates PtdIns(3,4,5)P3, placing opsismodysplasia in the phosphoinositide signaling disease spectrum (feist2016novelcompoundheterozygous pages 3-4).
GO phosphatidylinositol dephosphorylation GO:0046854 Core biochemical mechanism inferred from SHIP2 enzymatic function and disease-causing catalytic-domain variants (celine2013exomesequencingidentifies pages 4-4, edimo2014ship2signalingin pages 3-5).
GO phosphoinositide metabolic process GO:0046488 INPPL1 regulates levels of specific phosphoinositides; disease likely reflects disrupted phosphoinositide turnover in skeletal development (celine2013exomesequencingidentifies pages 4-4, celine2013exomesequencingidentifies pages 1-2).
GO phosphatidylinositol 3-kinase signaling GO:0014065 SHIP2 functions within the PI3K pathway by turning over PI3K-generated PtdIns(3,4,5)P3; loss is expected to alter PI3K pathway output (celine2013exomesequencingidentifies pages 4-4, feist2016novelcompoundheterozygous pages 3-4).
GO positive regulation of AKT signaling GO:0051897 SHIP2 normally reduces PtdIns(3,4,5)P3 and can inhibit AKT signaling; thus disease-causing loss likely perturbs AKT pathway regulation, though cartilage-specific AKT readouts remain limited (muller2024thefunctionalroles pages 14-15).
GO endochondral ossification GO:0001958 Most directly implicated developmental process; patient histology and skeletal findings indicate a primary defect in endochondral ossification with delayed epiphyseal ossification (celine2013exomesequencingidentifies pages 1-2, feist2016novelcompoundheterozygous pages 3-4).
GO chondrocyte differentiation GO:0002063 Growth plate histology shows reduced hypertrophic zone and fewer hypertrophic chondrocytes, consistent with impaired chondrocyte maturation/differentiation (celine2013exomesequencingidentifies pages 1-2).
GO chondrocyte proliferation GO:0035988 Near-absence of normal columnar organization in the proliferative zone supports altered proliferative chondrocyte behavior (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2).
GO fibroblast growth factor receptor signaling pathway GO:0008543 Zebrafish Ship2 knockdown perturbs FGF signaling and developmental patterning, suggesting a plausible conserved mechanism relevant to skeletal morphogenesis (celine2013exomesequencingidentifies pages 4-6, edimo2014ship2signalingin pages 3-5).
GO cell growth GO:0016049 Recent zebrafish inppl1a data support a role in cell expansion and endochondral bone lengthening, extending the growth-regulatory disease model (voigt2024aconservedregulation pages 1-3).
GO establishment or maintenance of cell polarity GO:0007163 SHIP2 has non-catalytic roles in polarity/migration pathways, relevant because growth plate organization is disrupted in disease (celine2013exomesequencingidentifies pages 4-6, edimo2014ship2signalingin pages 3-5).
GO cell migration GO:0016477 SHIP2 participates in migration/polarity signaling via phosphoinositides and cytoskeletal interactions; included as a plausible contributing process rather than OPS-specific proven mechanism (celine2013exomesequencingidentifies pages 4-6, edimo2014ship2signalingin pages 3-5).
GO plasma membrane GO:0005886 SHIP2 acts on membrane phosphoinositides such as PtdIns(3,4,5)P3 at the plasma membrane (muller2024thefunctionalroles pages 14-15).
GO cytosol GO:0005829 SHIP2 also functions in intracellular signaling complexes and docking interactions involving cytoskeletal/scaffold proteins (celine2013exomesequencingidentifies pages 4-6, feist2016novelcompoundheterozygous pages 4-7).
HP Short stature HP:0004322 Severe pre- and postnatal growth deficiency is a consistent phenotype in surviving patients (celine2013exomesequencingidentifies pages 4-4, below2013wholegenomeanalysisreveals pages 5-7).
HP Micromelia HP:0002983 Pre- and postnatal micromelia/short long bones are characteristic clinical findings (celine2013exomesequencingidentifies pages 4-4, celine2013exomesequencingidentifies pages 1-2).
HP Delayed ossification of epiphyses HP:0003093 Delayed epiphyseal ossification is repeatedly described and is central to disease definition (muller2024thefunctionalroles pages 14-15, li2014opsismodysplasiaresultingfrom pages 1-3).
HP Platyspondyly HP:0000926 Severe platyspondyly is a hallmark radiographic feature (feist2016novelcompoundheterozygous pages 3-4, li2014opsismodysplasiaresultingfrom pages 1-3).
HP Scoliosis HP:0002650 Severe scoliosis has been reported in survivors; zebrafish inppl1a mutants also develop spinal curvature, supporting mechanistic relevance (celine2013exomesequencingidentifies pages 4-4, voigt2024aconservedregulation pages 1-3).
HP Narrow thorax HP:0000774 Narrow chest/thorax contributes to respiratory compromise in severe neonatal presentations (celine2013exomesequencingidentifies pages 4-4).
HP Pulmonary hypoplasia HP:0002089 Reported in severe prenatal/perinatal cases and likely secondary to restricted thoracic development (celine2013exomesequencingidentifies pages 4-4).
HP Craniofacial abnormality HP:0001999 Craniofacial abnormalities/large neurocranium/shortened facial profile are reported in patients and mouse models (feist2016novelcompoundheterozygous pages 3-4, below2013wholegenomeanalysisreveals pages 5-7).
HP Decreased bone mineral density HP:0004349 Low bone density/undermineralization has been documented clinically (below2013wholegenomeanalysisreveals pages 5-7, li2014opsismodysplasiaresultingfrom pages 1-3).
HP Renal phosphate wasting HP:0000117 Renal phosphate wasting was described in an INPPL1-mutant patient, with phosphate replacement improving some outcomes (li2014opsismodysplasiaresultingfrom pages 1-3).
CL chondrocyte CL:0000138 Principal disease-relevant cell type in growth plate cartilage (celine2013exomesequencingidentifies pages 1-2, feist2016novelcompoundheterozygous pages 3-4).
CL hypertrophic chondrocyte CL:0002333 Reduced hypertrophic zone/fewer hypertrophic chondrocytes on histology implicate this maturation stage (celine2013exomesequencingidentifies pages 1-2).
CL proliferative chondrocyte CL:0002334 Disorganized proliferative zones with near-absent columnar arrangement strongly implicate proliferative chondrocytes (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2).
UBERON growth plate cartilage UBERON:0003429 Primary anatomic site of pathology based on fetal histology and endochondral growth defects (feist2016novelcompoundheterozygous pages 3-4, celine2013exomesequencingidentifies pages 1-2).
UBERON epiphysis UBERON:0004352 Delayed epiphyseal ossification is a defining radiographic/clinical feature (muller2024thefunctionalroles pages 14-15, li2014opsismodysplasiaresultingfrom pages 1-3).
UBERON vertebral column UBERON:0001130 Platyspondyly, vertebral abnormalities, and scoliosis indicate major vertebral involvement (below2013wholegenomeanalysisreveals pages 5-7, voigt2024aconservedregulation pages 1-3).
UBERON long bone UBERON:0002371 Short long bones, bowing, and metaphyseal changes are prominent manifestations (celine2013exomesequencingidentifies pages 4-4, li2014opsismodysplasiaresultingfrom pages 1-3).
UBERON pelvis UBERON:0001270 Poor ossification of pelvic bones and poorly formed acetabula are recurrent imaging findings (below2013wholegenomeanalysisreveals pages 5-7, feist2016novelcompoundheterozygous pages 4-7).
CHEBI phosphatidylinositol 3,4,5-trisphosphate CHEBI:16595 Direct SHIP2 substrate; excess/abnormal handling is central to proposed disease mechanism (feist2016novelcompoundheterozygous pages 3-4, muller2024thefunctionalroles pages 14-15).
CHEBI phosphatidylinositol 3,4-bisphosphate CHEBI:17289 Key SHIP2 product; reduced PI(3,4)P2 has been emphasized as mechanistically important in SHIP2-deficient phenotypes (edimo2014ship2signalingin pages 3-5).
CHEBI AS1949490 not available SHIP2-selective inhibitor discussed in 2024 review; relevant as a mechanistic chemical probe, not an opsismodysplasia therapy (muller2024thefunctionalroles pages 14-15).

Table: This table maps core opsismodysplasia mechanisms, phenotypes, cells, tissues, and chemicals to ontology-style identifiers suitable for knowledge-base curation. It emphasizes the INPPL1/SHIP2-centered phosphoinositide signaling defect and its links to growth plate disorganization and impaired endochondral ossification.

13. Evidence items with PMIDs (primary literature prioritized)

  • Below et al., AJHG (2013) Whole-genome analysis; INPPL1 mutations in 58% of kindreds and 50% of simplex cases; links to mouse developmental growth phenotypes. PMID: 23273569; DOI: 10.1016/j.ajhg.2012.11.011; Published Jan 2013. (below2013wholegenomeanalysisreveals pages 5-7)
  • Huber et al., AJHG (2013) Exome sequencing; 12 INPPL1 mutations in 10 families; growth plate disorganization and reduced hypertrophic zone. DOI: 10.1016/j.ajhg.2012.11.015; Published Jan 2013. (celine2013exomesequencingidentifies pages 1-2)

Limitations of the current evidence base

Opsismodysplasia is ultra-rare; as a result, the most direct growth-plate mechanistic evidence remains concentrated in the 2013 discovery literature and a limited number of follow-up reports. Recent (2023–2024) work strengthens general SHIP2 signaling context and provides new model-organism evidence for skeletal growth roles, but cartilage-specific PI3K–AKT/FGF pathway readouts in human growth plate cells remain sparse in the accessible literature set. (edimo2014ship2signalingin pages 3-5, muller2024thefunctionalroles pages 14-15, voigt2024aconservedregulation pages 1-3)

References

  1. (muller2024thefunctionalroles pages 14-15): Spike Murphy Müller and Manfred Jücker. The functional roles of the src homology 2 domain-containing inositol 5-phosphatases ship1 and ship2 in the pathogenesis of human diseases. International Journal of Molecular Sciences, 25:5254, May 2024. URL: https://doi.org/10.3390/ijms25105254, doi:10.3390/ijms25105254. This article has 16 citations.

  2. (below2013wholegenomeanalysisreveals pages 5-7): Jennifer E. Below, Dawn L. Earl, Kathryn M. Shively, Margaret J. McMillin, Joshua D. Smith, Emily H. Turner, Mark J. Stephan, Lihadh I. Al-Gazali, Jozef L. Hertecant, David Chitayat, Sheila Unger, Daniel H. Cohn, Deborah Krakow, James M. Swanson, Elaine M. Faustman, Jay Shendure, Deborah A. Nickerson, and Michael J. Bamshad. Whole-genome analysis reveals that mutations in inositol polyphosphate phosphatase-like 1 cause opsismodysplasia. American journal of human genetics, 92 1:137-43, Jan 2013. URL: https://doi.org/10.1016/j.ajhg.2012.11.011, doi:10.1016/j.ajhg.2012.11.011. This article has 67 citations and is from a highest quality peer-reviewed journal.

  3. (celine2013exomesequencingidentifies pages 1-2): Céline Huber, Eissa Ali Faqeih, Deborah Bartholdi, Christine Bole-Feysot, Zvi Borochowitz, Denise P Cavalcanti, Amandine Frigo, Patrick Nitschke, Joelle Roume, Heloísa G Santos, Stavit A Shalev, Andrea Superti-Furga, Anne-Lise Delezoide, Martine Le Merrer, Arnold Munnich, and Valérie Cormier-Daire. Exome sequencing identifies inppl1 mutations as a cause of opsismodysplasia. American journal of human genetics, 92 1:144-9, Jan 2013. URL: https://doi.org/10.1016/j.ajhg.2012.11.015, doi:10.1016/j.ajhg.2012.11.015. This article has 62 citations and is from a highest quality peer-reviewed journal.

  4. (feist2016novelcompoundheterozygous pages 3-4): Cori Feist, Paul Holden, and Jamie Fitzgerald. Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia. Clinical Dysmorphology, 25:152–155, Oct 2016. URL: https://doi.org/10.1097/mcd.0000000000000136, doi:10.1097/mcd.0000000000000136. This article has 10 citations and is from a peer-reviewed journal.

  5. (celine2013exomesequencingidentifies pages 4-4): Céline Huber, Eissa Ali Faqeih, Deborah Bartholdi, Christine Bole-Feysot, Zvi Borochowitz, Denise P Cavalcanti, Amandine Frigo, Patrick Nitschke, Joelle Roume, Heloísa G Santos, Stavit A Shalev, Andrea Superti-Furga, Anne-Lise Delezoide, Martine Le Merrer, Arnold Munnich, and Valérie Cormier-Daire. Exome sequencing identifies inppl1 mutations as a cause of opsismodysplasia. American journal of human genetics, 92 1:144-9, Jan 2013. URL: https://doi.org/10.1016/j.ajhg.2012.11.015, doi:10.1016/j.ajhg.2012.11.015. This article has 62 citations and is from a highest quality peer-reviewed journal.

  6. (feist2016novelcompoundheterozygous media 56a554cb): Cori Feist, Paul Holden, and Jamie Fitzgerald. Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia. Clinical Dysmorphology, 25:152–155, Oct 2016. URL: https://doi.org/10.1097/mcd.0000000000000136, doi:10.1097/mcd.0000000000000136. This article has 10 citations and is from a peer-reviewed journal.

  7. (edimo2014ship2signalingin pages 3-5): William's Elong Edimo, Stéphane Schurmans, Pierre P. Roger, and Christophe Erneux. Ship2 signaling in normal and pathological situations: its impact on cell proliferation. Advances in Biological Regulation, 54:142-151, Jan 2014. URL: https://doi.org/10.1016/j.jbior.2013.09.002, doi:10.1016/j.jbior.2013.09.002. This article has 37 citations and is from a peer-reviewed journal.

  8. (celine2013exomesequencingidentifies pages 4-6): Céline Huber, Eissa Ali Faqeih, Deborah Bartholdi, Christine Bole-Feysot, Zvi Borochowitz, Denise P Cavalcanti, Amandine Frigo, Patrick Nitschke, Joelle Roume, Heloísa G Santos, Stavit A Shalev, Andrea Superti-Furga, Anne-Lise Delezoide, Martine Le Merrer, Arnold Munnich, and Valérie Cormier-Daire. Exome sequencing identifies inppl1 mutations as a cause of opsismodysplasia. American journal of human genetics, 92 1:144-9, Jan 2013. URL: https://doi.org/10.1016/j.ajhg.2012.11.015, doi:10.1016/j.ajhg.2012.11.015. This article has 62 citations and is from a highest quality peer-reviewed journal.

  9. (voigt2024aconservedregulation pages 1-3): Brittney Voigt, Katherine Frazier, Donya Yazdi, Paul Gontarz, Bo Zhang, Diane S. Sepich, Lilianna Solnica-Krezel, and Ryan S. Gray. A conserved regulation of cell expansion underlies notochord mechanics, spine morphogenesis, and endochondral bone lengthening. bioRxiv, Aug 2024. URL: https://doi.org/10.1101/2024.08.12.607640, doi:10.1101/2024.08.12.607640. This article has 2 citations.

  10. (li2014opsismodysplasiaresultingfrom pages 1-3): Bing Li, Deborah Krakow, Deborah A. Nickerson, Michael J. Bamshad, Yong Chang, Ralph S. Lachman, Alev Yilmaz, Hülya Kayserili, and Daniel H. Cohn. Opsismodysplasia resulting from an insertion mutation in the sh2 domain, which destabilizes inppl1. American Journal of Medical Genetics Part A, 164:2407-2411, Jun 2014. URL: https://doi.org/10.1002/ajmg.a.36640, doi:10.1002/ajmg.a.36640. This article has 19 citations.

  11. (feist2016novelcompoundheterozygous pages 4-7): Cori Feist, Paul Holden, and Jamie Fitzgerald. Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia. Clinical Dysmorphology, 25:152–155, Oct 2016. URL: https://doi.org/10.1097/mcd.0000000000000136, doi:10.1097/mcd.0000000000000136. This article has 10 citations and is from a peer-reviewed journal.