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1
Mappings
1
Inheritance
9
Pathophys.
9
Phenotypes
10
Pathograph
1
Genes
6
Medical Actions
3
Differentials
1
Datasets
1
Deep Research
🔗

Mappings

MONDO
MONDO:0033664 Kilquist syndrome
skos:exactMatch MONDO
👪

Inheritance

1
Autosomal recessive inheritance HP:0000007
Kilquist syndrome is caused by biallelic loss of function of SLC12A2.
Autosomal recessive inheritance
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Like other SLC12 gene family disorders, Kilquist syndrome is an autosomal recessive condition caused by the loss of function of SLC12A2."
This directly states the mode of inheritance and causal mechanism.

Pathophysiology

9
Biallelic SLC12A2 / NKCC1 deficiency
Kilquist syndrome is caused by biallelic pathogenic variants in SLC12A2, which encodes the NKCC1 cotransporter.
SLC12A2 hgnc:10911
monoatomic ion transmembrane transport GO:0034220 ⚠ ABNORMAL
Show evidence (2 references)
PMID:30740830 SUPPORT Human Clinical
"Next-generation sequencing revealed a uniparental isodisomy in chromosome 5, and a 22 kb homozygous deletion in SLC12A2, which encodes for sodium, potassium, and chloride transporter in the basolateral membrane of secretory epithelia."
This directly anchors the syndrome to a biallelic SLC12A2 lesion affecting the NKCC1 transporter.
PMID:30740830 SUPPORT Other
"Together with the described phenotype of the Slc12a2-knockout mouse model, our results suggest that the absence of functional SLC12A2 causes a new genetic syndrome and is crucial for the development of auditory, neurologic, and gastrointestinal tissues."
This integrates the human proband with model-organism context; tissue-level inferences below are separated into human, model, and in vitro evidence.
Truncated or absent NKCC1 protein
Pathogenic splice variants produce truncated NKCC1 and impair dimerization or eliminate detectable transporter protein.
SLC12A2 hgnc:10911
Show evidence (3 references)
PMID:40678848 SUPPORT In Vitro
"The effect of this mutation was further investigated using exon-walking PCR and Sanger sequencing, which confirmed exon 23 skipping in the patient's mRNA, resulting in a truncated NKCC1 protein."
This directly supports RNA-level and protein-level disruption of NKCC1.
PMID:40678848 SUPPORT Computational
"In silico structural modeling suggested compromised dimerization stability"
This supports a computationally inferred structural mechanism in which mutant NKCC1 has impaired dimerization stability.
PMID:40678848 SUPPORT In Vitro
"immunoblotting analysis, revealing the absence of the dimeric form of NKCC1 in patient-derived peripheral blood mononuclear cells."
This provides cell-based support that the mutant transporter fails to form the normal dimeric state.
Cochlear endolymph secretion failure
NKCC1 deficiency disrupts the inner-ear fluid-secretion program required for normal auditory function and underlies profound hearing loss.
Show evidence (1 reference)
PMID:30740830 SUPPORT Model Organism
"The hallmark feature of the NKCC1 knockout mouse is a “shaker/waltzer” phenotype characteristic of inner ear dysfunction, histologically seen as a complete collapse of the cochlear duct"
The cochlear endolymph branch is primarily supported by mouse knockout inner-ear pathology, with human profound hearing loss as the clinical correlate.
Neuronal ion-homeostasis disruption
NKCC1 deficiency perturbs neuronal chloride transport and brain-development programs, contributing to severe developmental impairment and hypotonia.
Show evidence (1 reference)
PMID:30740830 PARTIAL Model Organism
"In the mouse model, NKCC1 is necessary for maintaining normal neuronal migration, and is implicated in dendritic growth and increasing neuron density through its regulation of GABAergic signaling"
This mechanistic neuronal-development branch is model-supported and plausibly explains human developmental delay, but is not directly assayed in human neural tissue.
Secretory epithelial fluid-secretion failure
Loss of NKCC1 compromises secretory epithelial function, producing marked salivary and other exocrine secretion defects with gastrointestinal and respiratory consequences.
Show evidence (2 references)
PMID:30740830 SUPPORT Human Clinical
"Our case is the first known human presentation of complete loss of NKCC1 and demonstrates the role of SLC12A2 in human secretory systems and disease."
This directly supports a secretory-epithelial branch downstream of NKCC1 loss.
PMID:30740830 SUPPORT Model Organism
"NKCC1 knockout mice show a significant reduction in saliva production due to the inability of the parotid gland to conserve NaCl"
Provides model-organism support for salivary epithelial secretion failure.
Profound sensorineural hearing impairment
Inner-ear dysfunction produces the hallmark profound bilateral sensorineural hearing loss of Kilquist syndrome.
Show evidence (1 reference)
PMID:40678848 SUPPORT Human Clinical
"This study presents the case of a child with multiple congenital anomalies, severe hypotonia, and profound bilateral sensorineural hearing loss."
This supports the phenotype-level auditory outcome downstream of cochlear NKCC1 dysfunction.
Severe neurodevelopmental impairment
Neuronal NKCC1 dysfunction contributes to global developmental delay and hypotonia.
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Herein we describe a child admitted to the NIH Undiagnosed Diseases Program with global developmental delay, sensorineural hearing loss, gastrointestinal abnormalities, and absent salivation."
This directly supports severe neurodevelopmental impairment as a downstream outcome in the human syndrome.
Xerostomia and epithelial secretion defects
Secretory failure produces profound impairment of salivary and other epithelial secretions.
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"This new syndrome is associated with a loss of function mutation in SLC12A2; we now refer to this novel disease as Kilquist syndrome, which is additionally characterized by the absence of saliva, tears, and sweat, mucus plugging and respiratory problems reminiscent of cystic fibrosis, and severe..."
This directly supports epithelial secretion failure as a distinct downstream branch of disease.
Gastrointestinal and respiratory complications
NKCC1-related secretory dysfunction contributes to severe gastrointestinal abnormalities and mucus-related respiratory disease.
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"In summary, we present a novel cause of syndromic hearing loss associated with global developmental delay, failure to thrive, respiratory problems, absent salivation and sweat production, and gastrointestinal abnormalities."
This directly supports downstream gastrointestinal and respiratory complications in the human syndrome.

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Kilquist syndrome 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

9
Cardiovascular 1
Absent tear production with dry eye risk Keratoconjunctivitis sicca HP:0001097
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Schirmer test confirmed absence of tears (<1mm bilaterally)."
Directly documents absent lacrimation; the linked HPO term captures the resulting tear-film deficiency/dry-eye phenotype.
Ear 1
Sensorineural hearing impairment Sensorineural hearing impairment HP:0000407
Show evidence (1 reference)
PMID:40678848 SUPPORT Human Clinical
"This study presents the case of a child with multiple congenital anomalies, severe hypotonia, and profound bilateral sensorineural hearing loss."
This directly supports profound sensorineural hearing loss as a core phenotype.
Head and Neck 1
Xerostomia Xerostomia HP:0000217
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"This new syndrome is associated with a loss of function mutation in SLC12A2; we now refer to this novel disease as Kilquist syndrome, which is additionally characterized by the absence of saliva, tears, and sweat, mucus plugging and respiratory problems reminiscent of cystic fibrosis, and severe..."
This directly supports severe salivary deficiency as a core phenotype.
Musculoskeletal 1
Hypotonia Hypotonia HP:0001252
Show evidence (1 reference)
PMID:40678848 SUPPORT Human Clinical
"This study presents the case of a child with multiple congenital anomalies, severe hypotonia, and profound bilateral sensorineural hearing loss."
This directly supports hypotonia as part of the phenotype.
Nervous System 1
Global developmental delay Global developmental delay HP:0001263
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Herein we describe a child admitted to the NIH Undiagnosed Diseases Program with global developmental delay, sensorineural hearing loss, gastrointestinal abnormalities, and absent salivation."
The original syndrome description directly identifies global developmental delay.
Growth 1
Failure to thrive Failure to thrive HP:0001508
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"In summary, we present a novel cause of syndromic hearing loss associated with global developmental delay, failure to thrive, respiratory problems, absent salivation and sweat production, and gastrointestinal abnormalities."
The syndrome summary explicitly includes failure to thrive.
Other 3
Anhidrosis Anhidrosis HP:0000970
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"No sympathetic postganglionic cholinergic function was observed in either the forearm or ankle by QSWEAT test, demonstrating sympathetic postganglionic sweat dysfunction"
Supports sweat-production failure as a documented Kilquist syndrome phenotype.
Mucus plugging with respiratory problems Airway obstruction HP:0006536
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"mucus plugging and respiratory problems reminiscent of cystic fibrosis"
Supports mucus-related respiratory disease as a human clinical phenotype.
Gastrointestinal dysmotility and malrotation Gastrointestinal dysmotility HP:0002579
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Our patient has a history of significant gastrointestinal problems including malrotation, constipation, and concern for blood in the GI tract based on periodic coffee-ground G-tube aspirations."
Supports severe gastrointestinal involvement with dysmotility-compatible features in the foundational patient.
🧬

Genetic Associations

1
SLC12A2 (Loss-of-function)
Gene: SLC12A2 hgnc:10911
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Like other SLC12 gene family disorders, Kilquist syndrome is an autosomal recessive condition caused by the loss of function of SLC12A2."
This directly supports the causal gene and variant mechanism.
💊

Medical Actions

6
Supportive multidisciplinary management
Action: supportive care MAXO:0000950
Management remains supportive and should be multidisciplinary because the reported biallelic cases involve profound hearing loss, severe developmental impairment, growth failure, gastrointestinal abnormalities, and secretory epithelial complications.
Show evidence (1 reference)
PMID:30740830 PARTIAL Human Clinical
"In summary, we present a novel cause of syndromic hearing loss associated with global developmental delay, failure to thrive, respiratory problems, absent salivation and sweat production, and gastrointestinal abnormalities."
This multisystem case summary supports multidisciplinary supportive management, while not providing interventional efficacy data.
Hearing rehabilitation and cochlear implantation
Action: cochlear device implantation MAXO:0009025
Hearing-directed management may include hearing aids, cochlear implant evaluation, and ongoing audiology support, but published experience is limited and benefit may be incomplete.
Show evidence (1 reference)
PMID:30740830 PARTIAL Human Clinical
"Cochlear implants were placed although the parents not that he has functionally derived no benefit."
The report documents cochlear implantation but also reports absent functional benefit, so this only partially supports hearing-directed intervention.
Gastrostomy and nutrition support
Action: gastrostomy MAXO:0001346
Nutrition support, feeding therapy, and gastrostomy care may be required for severe growth failure and feeding/GI complications.
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Insufficient weight gain following surgery necessitated gastronomy tube placement."
The source documents tube placement for persistent weight-gain failure; the wording preserves the source's typographical error.
Pulmonary mucus and airway support
Action: respiratory tract agent therapy MAXO:0000312
Respiratory management should address mucus plugging, airway obstruction, and cystic-fibrosis-like pulmonary complications when present.
Show evidence (1 reference)
PMID:30740830 PARTIAL Human Clinical
"mucus plugging and respiratory problems reminiscent of cystic fibrosis"
The evidence supports respiratory mucus complications but does not test a specific pulmonary therapy, so treatment support is partial.
Ocular and oral secretion support
Action: supportive care MAXO:0000950
Supportive management should include care for absent tear production, xerostomia, and related oral or ocular surface complications.
Show evidence (1 reference)
PMID:30740830 PARTIAL Human Clinical
"There was severe oral dryness and saliva was not able to be produced by massage of the salivary glands."
The evidence supports the secretion problem targeted by supportive care, but does not evaluate a specific treatment.
Developmental rehabilitation and supportive care
Action: supportive care MAXO:0000950
Children with Kilquist syndrome should receive developmental surveillance and rehabilitation services tailored to profound global developmental impairment and hypotonia.
Show evidence (1 reference)
PMID:30740830 PARTIAL Human Clinical
"Neuropsychological testing demonstrated profound delays in all developmental areas, with skills ranging from 1 to 6 months."
The evidence supports the need for developmental support, but does not provide outcome data for a specific rehabilitation program.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Kilquist syndrome:

Dominant SLC12A2-related cochleovestibular or neurodevelopmental disorder
Overlapping Features Heterozygous or de novo SLC12A2 variants can cause distinct dominant phenotypes, including cochlea-restricted deafness with vestibular areflexia and neurodevelopmental disorders. Those entities overlap genetically but are not the biallelic Kilquist syndrome entity curated here.
Distinguishing Features
  • Biallelic loss-of-function SLC12A2 variants with severe multisystem secretory and gastrointestinal involvement favor Kilquist syndrome.
  • Heterozygous exon 21 or de novo variants with isolated cochleovestibular disease or a dominant neurodevelopmental presentation favor the separate dominant SLC12A2-related spectrum.
Show evidence (4 references)
PMID:40503591 SUPPORT Human Clinical
"Subsequently, several patients with severe developmental delay, sensorineural hearing loss, and bi-allelic loss of function variants were reported; this condition is known as Kilquist syndrome."
This review-style introduction distinguishes the biallelic Kilquist syndrome entity from other SLC12A2-linked phenotypes.
PMID:40503591 SUPPORT Human Clinical
"In 2020, heterozygous variants in SLC12A2 were identified as a cause of non-syndromic deafness associated with vestibular areflexia (DFNA78; MIM 619081)."
This supports a separate heterozygous cochleovestibular SLC12A2 condition that should not be merged into Kilquist syndrome.
PMID:32658972 SUPPORT Human Clinical
"Through trio exome sequencing we identified de novo mutations in SLC12A2 in six children with neurodevelopmental disorders."
This supports a distinct de novo heterozygous neurodevelopmental SLC12A2-related spectrum.
+ 1 more reference
Overlapping Features Kilquist syndrome can resemble cystic fibrosis because of mucus plugging, poor growth, and gastrointestinal symptoms, but it is distinguished by profound congenital hearing loss and biallelic SLC12A2 deficiency.
Distinguishing Features
  • Profound sensorineural hearing loss and absent salivation favor Kilquist syndrome.
  • Positive CFTR-associated testing and classic pancreatic-pulmonary phenotype favor cystic fibrosis.
Usher syndrome Not Yet Curated MONDO:0019501
Overlapping Features Usher syndrome overlaps with Kilquist syndrome through congenital hearing loss, but Kilquist syndrome is distinguished by severe gastrointestinal and secretory epithelial dysfunction rather than retinitis pigmentosa.
Distinguishing Features
  • Global developmental delay and absent epithelial secretions favor Kilquist syndrome.
  • Progressive retinopathy with deafblindness favors Usher syndrome.
📊

Related Datasets

1
Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2. PMID:30740830
Foundational human case-based dataset defining Kilquist syndrome through deep clinical phenotyping, genomic diagnosis, and fibroblast-based functional validation of complete NKCC1 loss.
human n=1
Conditions: Kilquist syndrome homozygous SLC12A2 deletion
PMID:30740830
Show evidence (1 reference)
PMID:30740830 SUPPORT Human Clinical
"Herein we describe a child admitted to the NIH Undiagnosed Diseases Program with global developmental delay, sensorineural hearing loss, gastrointestinal abnormalities, and absent salivation."
This supports the publication as the foundational disease-defining human phenotype dataset for Kilquist syndrome.
{ }

Source YAML

click to show
name: Kilquist syndrome
creation_date: '2026-04-11T19:38:25Z'
updated_date: '2026-05-31T11:05:00Z'
category: Mendelian
description: >-
  Kilquist syndrome is an ultra-rare autosomal recessive multisystem disorder
  caused by biallelic loss-of-function variants in SLC12A2, which encodes the
  NKCC1 sodium-potassium-chloride cotransporter. This entry is scoped to the
  biallelic Kilquist syndrome phenotype rather than the broader dominant
  SLC12A2-related cochleovestibular/neurodevelopmental spectrum. Loss of NKCC1
  disrupts ion transport in the cochlea, neurons, and secretory epithelia,
  producing profound sensorineural hearing loss, severe developmental delay,
  hypotonia, growth failure, gastrointestinal abnormalities, and marked
  impairment of saliva, tears, sweat, and respiratory mucus handling.
disease_term:
  preferred_term: Kilquist syndrome
  term:
    id: MONDO:0033664
    label: Kilquist syndrome
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0033664
      label: Kilquist syndrome
    mapping_predicate: skos:exactMatch
    mapping_source: MONDO
parents:
- hereditary disease
- syndromic hearing loss
inheritance:
- name: Autosomal recessive inheritance
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  description: >-
    Kilquist syndrome is caused by biallelic loss of function of SLC12A2.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Like other SLC12 gene family disorders, Kilquist syndrome is an autosomal recessive condition caused by the loss of function of SLC12A2.
    explanation: >-
      This directly states the mode of inheritance and causal mechanism.
pathophysiology:
- name: Biallelic SLC12A2 / NKCC1 deficiency
  description: >-
    Kilquist syndrome is caused by biallelic pathogenic variants in SLC12A2,
    which encodes the NKCC1 cotransporter.
  genes:
  - preferred_term: SLC12A2
    term:
      id: hgnc:10911
      label: SLC12A2
  biological_processes:
  - preferred_term: monoatomic ion transmembrane transport
    modifier: ABNORMAL
    term:
      id: GO:0034220
      label: monoatomic ion transmembrane transport
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Next-generation sequencing revealed a uniparental isodisomy in chromosome 5, and a 22 kb homozygous deletion in SLC12A2, which encodes for sodium, potassium, and chloride transporter in the basolateral membrane of secretory epithelia.
    explanation: >-
      This directly anchors the syndrome to a biallelic SLC12A2 lesion affecting
      the NKCC1 transporter.
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Together with the described phenotype of the Slc12a2-knockout mouse model, our results suggest that the absence of functional SLC12A2 causes a new genetic syndrome and is crucial for the development of auditory, neurologic, and gastrointestinal tissues.
    explanation: >-
      This integrates the human proband with model-organism context; tissue-level
      inferences below are separated into human, model, and in vitro evidence.
  downstream:
  - target: Truncated or absent NKCC1 protein
    description: Biallelic pathogenic variants abolish normal NKCC1 protein production or stability
- name: Truncated or absent NKCC1 protein
  description: >-
    Pathogenic splice variants produce truncated NKCC1 and impair dimerization or
    eliminate detectable transporter protein.
  genes:
  - preferred_term: SLC12A2
    term:
      id: hgnc:10911
      label: SLC12A2
  evidence:
  - reference: PMID:40678848
    reference_title: "Identification and Characterization of a Novel Biallelic SLC12A2 Variant Associated With Kilquist Syndrome (OMIM #619080)."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      The effect of this mutation was further investigated using exon-walking PCR and Sanger sequencing, which confirmed exon 23 skipping in the patient's mRNA, resulting in a truncated NKCC1 protein.
    explanation: >-
      This directly supports RNA-level and protein-level disruption of NKCC1.
  - reference: PMID:40678848
    reference_title: "Identification and Characterization of a Novel Biallelic SLC12A2 Variant Associated With Kilquist Syndrome (OMIM #619080)."
    supports: SUPPORT
    evidence_source: COMPUTATIONAL
    snippet: In silico structural modeling suggested compromised dimerization stability
    explanation: >-
      This supports a computationally inferred structural mechanism in which
      mutant NKCC1 has impaired dimerization stability.
  - reference: PMID:40678848
    reference_title: "Identification and Characterization of a Novel Biallelic SLC12A2 Variant Associated With Kilquist Syndrome (OMIM #619080)."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      immunoblotting analysis, revealing the absence of the dimeric form of NKCC1 in patient-derived peripheral blood mononuclear cells.
    explanation: >-
      This provides cell-based support that the mutant transporter fails to form
      the normal dimeric state.
  downstream:
  - target: Cochlear endolymph secretion failure
    description: Loss of NKCC1 disrupts the inner-ear ion transport needed for hearing
  - target: Neuronal ion-homeostasis disruption
    description: Loss of NKCC1 perturbs neuronal chloride handling and early brain development
  - target: Secretory epithelial fluid-secretion failure
    description: Loss of NKCC1 compromises epithelial fluid secretion
- name: Cochlear endolymph secretion failure
  description: >-
    NKCC1 deficiency disrupts the inner-ear fluid-secretion program required for
    normal auditory function and underlies profound hearing loss.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      The hallmark feature of the NKCC1 knockout mouse is a “shaker/waltzer”
      phenotype characteristic of inner ear dysfunction, histologically seen as a
      complete collapse of the cochlear duct
    explanation: >-
      The cochlear endolymph branch is primarily supported by mouse knockout
      inner-ear pathology, with human profound hearing loss as the clinical
      correlate.
  downstream:
  - target: Profound sensorineural hearing impairment
    description: Cochlear fluid-homeostasis failure produces the syndrome's hallmark deafness
- name: Neuronal ion-homeostasis disruption
  description: >-
    NKCC1 deficiency perturbs neuronal chloride transport and brain-development
    programs, contributing to severe developmental impairment and hypotonia.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: PARTIAL
    evidence_source: MODEL_ORGANISM
    snippet: >-
      In the mouse model, NKCC1 is necessary for maintaining normal neuronal
      migration, and is implicated in dendritic growth and increasing neuron
      density through its regulation of GABAergic signaling
    explanation: >-
      This mechanistic neuronal-development branch is model-supported and
      plausibly explains human developmental delay, but is not directly assayed
      in human neural tissue.
  downstream:
  - target: Severe neurodevelopmental impairment
    description: Neuronal transport defects contribute to developmental delay and hypotonia
- name: Secretory epithelial fluid-secretion failure
  description: >-
    Loss of NKCC1 compromises secretory epithelial function, producing marked
    salivary and other exocrine secretion defects with gastrointestinal and
    respiratory consequences.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our case is the first known human presentation of complete loss of NKCC1 and demonstrates the role of SLC12A2 in human secretory systems and disease.
    explanation: >-
      This directly supports a secretory-epithelial branch downstream of NKCC1
      loss.
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      NKCC1 knockout mice show a significant reduction in saliva production due
      to the inability of the parotid gland to conserve NaCl
    explanation: >-
      Provides model-organism support for salivary epithelial secretion failure.
  downstream:
  - target: Xerostomia and epithelial secretion defects
    description: Secretory failure causes absent salivation and related epithelial symptoms
  - target: Gastrointestinal and respiratory complications
    description: Secretory failure contributes to severe GI dysfunction and mucus-related respiratory problems
- name: Profound sensorineural hearing impairment
  description: >-
    Inner-ear dysfunction produces the hallmark profound bilateral sensorineural
    hearing loss of Kilquist syndrome.
  evidence:
  - reference: PMID:40678848
    reference_title: "Identification and Characterization of a Novel Biallelic SLC12A2 Variant Associated With Kilquist Syndrome (OMIM #619080)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This study presents the case of a child with multiple congenital anomalies, severe hypotonia, and profound bilateral sensorineural hearing loss.
    explanation: >-
      This supports the phenotype-level auditory outcome downstream of cochlear
      NKCC1 dysfunction.
- name: Severe neurodevelopmental impairment
  description: >-
    Neuronal NKCC1 dysfunction contributes to global developmental delay and
    hypotonia.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Herein we describe a child admitted to the NIH Undiagnosed Diseases Program with global developmental delay, sensorineural hearing loss, gastrointestinal abnormalities, and absent salivation.
    explanation: >-
      This directly supports severe neurodevelopmental impairment as a downstream
      outcome in the human syndrome.
- name: Xerostomia and epithelial secretion defects
  description: >-
    Secretory failure produces profound impairment of salivary and other
    epithelial secretions.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This new syndrome is associated with a loss of function mutation in SLC12A2; we now refer to this novel disease as Kilquist syndrome, which is additionally characterized by the absence of saliva, tears, and sweat, mucus plugging and respiratory problems reminiscent of cystic fibrosis, and severe gastrointestinal problems.
    explanation: >-
      This directly supports epithelial secretion failure as a distinct
      downstream branch of disease.
- name: Gastrointestinal and respiratory complications
  description: >-
    NKCC1-related secretory dysfunction contributes to severe gastrointestinal
    abnormalities and mucus-related respiratory disease.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In summary, we present a novel cause of syndromic hearing loss associated with global developmental delay, failure to thrive, respiratory problems, absent salivation and sweat production, and gastrointestinal abnormalities.
    explanation: >-
      This directly supports downstream gastrointestinal and respiratory
      complications in the human syndrome.
phenotypes:
- name: Sensorineural hearing impairment
  category: Otolaryngologic
  description: >-
    Profound bilateral sensorineural hearing loss is the hallmark phenotype of
    Kilquist syndrome.
  phenotype_term:
    preferred_term: Sensorineural hearing impairment
    term:
      id: HP:0000407
      label: Sensorineural hearing impairment
  evidence:
  - reference: PMID:40678848
    reference_title: "Identification and Characterization of a Novel Biallelic SLC12A2 Variant Associated With Kilquist Syndrome (OMIM #619080)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This study presents the case of a child with multiple congenital anomalies, severe hypotonia, and profound bilateral sensorineural hearing loss.
    explanation: >-
      This directly supports profound sensorineural hearing loss as a core
      phenotype.
- name: Global developmental delay
  category: Neurologic
  description: >-
    Severe developmental impairment is part of the syndromic neurologic
    phenotype.
  phenotype_term:
    preferred_term: Global developmental delay
    term:
      id: HP:0001263
      label: Global developmental delay
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Herein we describe a child admitted to the NIH Undiagnosed Diseases Program with global developmental delay, sensorineural hearing loss, gastrointestinal abnormalities, and absent salivation.
    explanation: >-
      The original syndrome description directly identifies global developmental
      delay.
- name: Hypotonia
  category: Neurologic
  description: >-
    Generalized hypotonia is a recurrent neurologic feature in Kilquist
    syndrome.
  phenotype_term:
    preferred_term: Hypotonia
    term:
      id: HP:0001252
      label: Hypotonia
  evidence:
  - reference: PMID:40678848
    reference_title: "Identification and Characterization of a Novel Biallelic SLC12A2 Variant Associated With Kilquist Syndrome (OMIM #619080)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This study presents the case of a child with multiple congenital anomalies, severe hypotonia, and profound bilateral sensorineural hearing loss.
    explanation: >-
      This directly supports hypotonia as part of the phenotype.
- name: Failure to thrive
  category: Growth
  description: >-
    Poor growth and nutritional failure reflect the syndrome's severe
    gastrointestinal and secretory dysfunction.
  phenotype_term:
    preferred_term: Failure to thrive
    term:
      id: HP:0001508
      label: Failure to thrive
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In summary, we present a novel cause of syndromic hearing loss associated with global developmental delay, failure to thrive, respiratory problems, absent salivation and sweat production, and gastrointestinal abnormalities.
    explanation: >-
      The syndrome summary explicitly includes failure to thrive.
- name: Xerostomia
  category: Gastrointestinal
  description: >-
    Absent or severely reduced salivation is a hallmark secretory manifestation
    of Kilquist syndrome.
  phenotype_term:
    preferred_term: Xerostomia
    term:
      id: HP:0000217
      label: Xerostomia
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This new syndrome is associated with a loss of function mutation in SLC12A2; we now refer to this novel disease as Kilquist syndrome, which is additionally characterized by the absence of saliva, tears, and sweat, mucus plugging and respiratory problems reminiscent of cystic fibrosis, and severe gastrointestinal problems.
    explanation: >-
      This directly supports severe salivary deficiency as a core phenotype.
- name: Absent tear production with dry eye risk
  category: Ophthalmologic
  description: >-
    Absence of tear production reflects the same exocrine secretory failure that
    causes absent salivation and sweat production.
  phenotype_term:
    preferred_term: Absent tear production
    term:
      id: HP:0001097
      label: Keratoconjunctivitis sicca
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Schirmer test confirmed absence of tears (<1mm bilaterally).
    explanation: >-
      Directly documents absent lacrimation; the linked HPO term captures the
      resulting tear-film deficiency/dry-eye phenotype.
- name: Anhidrosis
  category: Dermatologic
  description: >-
    Absent or markedly impaired sweat production is part of the multisystem
    secretory epithelial phenotype.
  phenotype_term:
    preferred_term: Anhidrosis
    term:
      id: HP:0000970
      label: Anhidrosis
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      No sympathetic postganglionic cholinergic function was observed in either
      the forearm or ankle by QSWEAT test, demonstrating sympathetic
      postganglionic sweat dysfunction
    explanation: >-
      Supports sweat-production failure as a documented Kilquist syndrome
      phenotype.
- name: Mucus plugging with respiratory problems
  category: Respiratory
  description: >-
    Secretory epithelial dysfunction can produce mucus plugging and respiratory
    problems reminiscent of cystic fibrosis.
  phenotype_term:
    preferred_term: Mucus plugging with airway obstruction
    term:
      id: HP:0006536
      label: Airway obstruction
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      mucus plugging and respiratory problems reminiscent of cystic fibrosis
    explanation: >-
      Supports mucus-related respiratory disease as a human clinical phenotype.
- name: Gastrointestinal dysmotility and malrotation
  category: Gastrointestinal
  description: >-
    Severe gastrointestinal involvement includes malrotation, reflux,
    constipation, and broader dysmotility or secretion-related complications.
  phenotype_term:
    preferred_term: Gastrointestinal dysmotility
    term:
      id: HP:0002579
      label: Gastrointestinal dysmotility
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our patient has a history of significant gastrointestinal problems
      including malrotation, constipation, and concern for blood in the GI tract
      based on periodic coffee-ground G-tube aspirations.
    explanation: >-
      Supports severe gastrointestinal involvement with dysmotility-compatible
      features in the foundational patient.
genetic:
- name: SLC12A2
  association: Loss-of-function
  gene_term:
    preferred_term: SLC12A2
    term:
      id: hgnc:10911
      label: SLC12A2
  notes: >-
    Kilquist syndrome is caused by biallelic loss of NKCC1 function due to
    deletion or splice-disrupting variants in SLC12A2.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Like other SLC12 gene family disorders, Kilquist syndrome is an autosomal recessive condition caused by the loss of function of SLC12A2.
    explanation: >-
      This directly supports the causal gene and variant mechanism.
diagnosis:
- name: Deletion-sensitive SLC12A2 molecular genetic testing
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: MAXO:0000533
      label: molecular genetic testing
  description: >-
    Diagnosis is established by identifying biallelic pathogenic SLC12A2
    variants. Because reported biallelic disease includes both a homozygous
    deletion and a homozygous splice variant, testing should include sequencing
    plus deletion/duplication- or genome/CNV-sensitive methods.
  results: >-
    Biallelic loss-of-function SLC12A2 variants support the Kilquist syndrome
    diagnosis; isolated heterozygous variants should be interpreted in the
    separate dominant SLC12A2-related spectrum.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Whole genome-sequencing identified a homozygous deletion of 22kb in SLC12A2.
    explanation: >-
      The foundational case demonstrates a deletion-sensitive molecular
      diagnosis of biallelic SLC12A2 loss.
  - reference: PMID:40678848
    reference_title: "Identification and Characterization of a Novel Biallelic SLC12A2 Variant Associated With Kilquist Syndrome (OMIM #619080)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      genetic investigations confirmed the diagnosis by identifying a novel homozygous splice-site variant
    explanation: >-
      The second molecularly confirmed report supports sequence-level testing
      for biallelic SLC12A2 splice variants.
- name: Audiology evaluation with ABR and otoacoustic emissions
  diagnosis_term:
    preferred_term: hearing examination
    term:
      id: MAXO:0000873
      label: hearing examination
  description: >-
    Early audiology evaluation should document the severity and type of hearing
    loss using electrophysiologic testing, including auditory brainstem response
    and otoacoustic emissions when clinically available.
  results: >-
    Profound bilateral sensorineural hearing loss with absent otoacoustic
    emissions supports the auditory component of the Kilquist syndrome
    phenotype.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Auditory- brainstem evoked potentials (ABR) demonstrated profound bilateral sensorineural hearing loss, Distortion Product Otoacoustic Emissions (DPOAE) were absent bilaterally, and he was fitted with hearing aids.
    explanation: >-
      The report documents ABR and DPOAE findings used to characterize the
      profound sensorineural hearing phenotype.
- name: Neurodevelopmental assessment
  diagnosis_term:
    preferred_term: neurodevelopmental assessment
    term:
      id: MAXO:0035041
      label: neurodevelopmental assessment
  description: >-
    Formal developmental evaluation helps characterize the severe neurologic
    involvement, establish support needs, and distinguish biallelic Kilquist
    syndrome from cochlea-restricted dominant SLC12A2 presentations.
  results: >-
    Profound global delays across developmental domains support severe
    neurodevelopmental involvement.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neuropsychological testing demonstrated profound delays in all developmental areas, with skills ranging from 1 to 6 months.
    explanation: >-
      This supports neurodevelopmental testing as a key component of the
      phenotypic assessment.
- name: Nutrition and gastrointestinal assessment
  diagnosis_term:
    preferred_term: nutrition assessment
    term:
      id: MAXO:0000624
      label: nutrition assessment
  description: >-
    Growth, feeding, reflux, malrotation, constipation, and gastrostomy-tube
    complications should be assessed because severe nutritional and
    gastrointestinal problems are part of the reported biallelic syndrome.
  results: >-
    Failure to thrive, malnutrition, reflux, malrotation, constipation, or
    gastrostomy dependence identify major supportive-care needs.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      While his calorie, protein, and water intake exceed his estimated needs (>95% of required daily allowance), he was severely malnourished.
    explanation: >-
      The original case supports nutrition assessment because severe
      malnutrition occurred despite apparently adequate intake.
- name: Secretory epithelial assessment
  diagnosis_term:
    preferred_term: ophthalmic diagnostic procedure
    term:
      id: MAXO:0000967
      label: ophthalmic diagnostic procedure
  description: >-
    Schirmer testing, oral/salivary evaluation, sweat-function assessment, and
    review of mucus-related respiratory problems help document the
    secretory-epithelial arm of the syndrome.
  results: >-
    Absent tears, severe oral dryness, absent salivary production, sweat
    dysfunction, or mucus plugging support multisystem secretory failure.
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      An ophthalmologic exam was normal, although a Schirmer test confirmed absence of tears (<1mm bilaterally).
    explanation: >-
      The cited diagnostic procedure directly documented absent tear production.
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      There was severe oral dryness and saliva was not able to be produced by massage of the salivary glands.
    explanation: >-
      This supports targeted salivary assessment as part of documenting
      secretory epithelial failure.
treatments:
- name: Supportive multidisciplinary management
  description: >-
    Management remains supportive and should be multidisciplinary because the
    reported biallelic cases involve profound hearing loss, severe developmental
    impairment, growth failure, gastrointestinal abnormalities, and secretory
    epithelial complications.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In summary, we present a novel cause of syndromic hearing loss associated with global developmental delay, failure to thrive, respiratory problems, absent salivation and sweat production, and gastrointestinal abnormalities.
    explanation: >-
      This multisystem case summary supports multidisciplinary supportive
      management, while not providing interventional efficacy data.
- name: Hearing rehabilitation and cochlear implantation
  description: >-
    Hearing-directed management may include hearing aids, cochlear implant
    evaluation, and ongoing audiology support, but published experience is
    limited and benefit may be incomplete.
  treatment_term:
    preferred_term: cochlear device implantation
    term:
      id: MAXO:0009025
      label: cochlear device implantation
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Cochlear implants were placed although the parents not that he has functionally derived no benefit.
    explanation: >-
      The report documents cochlear implantation but also reports absent
      functional benefit, so this only partially supports hearing-directed
      intervention.
- name: Gastrostomy and nutrition support
  description: >-
    Nutrition support, feeding therapy, and gastrostomy care may be required for
    severe growth failure and feeding/GI complications.
  treatment_term:
    preferred_term: gastrostomy
    term:
      id: MAXO:0001346
      label: gastrostomy
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Insufficient weight gain following surgery necessitated gastronomy tube placement.
    explanation: >-
      The source documents tube placement for persistent weight-gain failure;
      the wording preserves the source's typographical error.
- name: Pulmonary mucus and airway support
  description: >-
    Respiratory management should address mucus plugging, airway obstruction, and
    cystic-fibrosis-like pulmonary complications when present.
  treatment_term:
    preferred_term: respiratory tract agent therapy
    term:
      id: MAXO:0000312
      label: respiratory tract agent therapy
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      mucus plugging and respiratory problems reminiscent of cystic fibrosis
    explanation: >-
      The evidence supports respiratory mucus complications but does not test a
      specific pulmonary therapy, so treatment support is partial.
- name: Ocular and oral secretion support
  description: >-
    Supportive management should include care for absent tear production,
    xerostomia, and related oral or ocular surface complications.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      There was severe oral dryness and saliva was not able to be produced by massage of the salivary glands.
    explanation: >-
      The evidence supports the secretion problem targeted by supportive care,
      but does not evaluate a specific treatment.
- name: Developmental rehabilitation and supportive care
  description: >-
    Children with Kilquist syndrome should receive developmental surveillance and
    rehabilitation services tailored to profound global developmental
    impairment and hypotonia.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neuropsychological testing demonstrated profound delays in all developmental areas, with skills ranging from 1 to 6 months.
    explanation: >-
      The evidence supports the need for developmental support, but does not
      provide outcome data for a specific rehabilitation program.
differential_diagnoses:
- name: Dominant SLC12A2-related cochleovestibular or neurodevelopmental disorder
  description: >-
    Heterozygous or de novo SLC12A2 variants can cause distinct dominant
    phenotypes, including cochlea-restricted deafness with vestibular areflexia
    and neurodevelopmental disorders. Those entities overlap genetically but are
    not the biallelic Kilquist syndrome entity curated here.
  distinguishing_features:
  - Biallelic loss-of-function SLC12A2 variants with severe multisystem secretory and gastrointestinal involvement favor Kilquist syndrome.
  - Heterozygous exon 21 or de novo variants with isolated cochleovestibular disease or a dominant neurodevelopmental presentation favor the separate dominant SLC12A2-related spectrum.
  evidence:
  - reference: PMID:40503591
    reference_title: De Novo SLC12A2 Variant Presenting as Congenital Hearing Loss With Vestibular Areflexia.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Subsequently, several patients with severe developmental delay, sensorineural hearing loss, and bi-allelic loss of function variants were reported; this condition is known as Kilquist syndrome.
    explanation: >-
      This review-style introduction distinguishes the biallelic Kilquist
      syndrome entity from other SLC12A2-linked phenotypes.
  - reference: PMID:40503591
    reference_title: De Novo SLC12A2 Variant Presenting as Congenital Hearing Loss With Vestibular Areflexia.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In 2020, heterozygous variants in SLC12A2 were identified as a cause of non-syndromic deafness associated with vestibular areflexia (DFNA78; MIM 619081).
    explanation: >-
      This supports a separate heterozygous cochleovestibular SLC12A2 condition
      that should not be merged into Kilquist syndrome.
  - reference: PMID:32658972
    reference_title: SLC12A2 variants cause a neurodevelopmental disorder or cochleovestibular defect.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Through trio exome sequencing we identified de novo mutations in SLC12A2 in six children with neurodevelopmental disorders.
    explanation: >-
      This supports a distinct de novo heterozygous neurodevelopmental
      SLC12A2-related spectrum.
  - reference: PMID:32294086
    reference_title: Variants encoding a restricted carboxy-terminal domain of SLC12A2 cause hereditary hearing loss in humans.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Using whole-exome analysis of three families with congenital, severe-to-profound hearing loss, we identified a missense variant of SLC12A2 in five affected members of one family showing a dominant inheritance mode, along with de novo splice-site and missense variants of SLC12A2 in two sporadic cases, as promising candidates associated with hearing loss.
    explanation: >-
      This supports dominant and de novo SLC12A2 hearing-loss presentations as a
      differential scope issue rather than biallelic Kilquist syndrome.
- name: Cystic fibrosis
  disease_term:
    preferred_term: cystic fibrosis
    term:
      id: MONDO:0009061
      label: cystic fibrosis
  description: >-
    Kilquist syndrome can resemble cystic fibrosis because of mucus plugging,
    poor growth, and gastrointestinal symptoms, but it is distinguished by
    profound congenital hearing loss and biallelic SLC12A2 deficiency.
  distinguishing_features:
  - Profound sensorineural hearing loss and absent salivation favor Kilquist syndrome.
  - Positive CFTR-associated testing and classic pancreatic-pulmonary phenotype favor cystic fibrosis.
- name: Usher syndrome
  disease_term:
    preferred_term: Usher syndrome
    term:
      id: MONDO:0019501
      label: Usher syndrome
  description: >-
    Usher syndrome overlaps with Kilquist syndrome through congenital hearing
    loss, but Kilquist syndrome is distinguished by severe gastrointestinal and
    secretory epithelial dysfunction rather than retinitis pigmentosa.
  distinguishing_features:
  - Global developmental delay and absent epithelial secretions favor Kilquist syndrome.
  - Progressive retinopathy with deafblindness favors Usher syndrome.
clinical_trials: []
datasets:
- accession: PMID:30740830
  title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
  description: >-
    Foundational human case-based dataset defining Kilquist syndrome through
    deep clinical phenotyping, genomic diagnosis, and fibroblast-based
    functional validation of complete NKCC1 loss.
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  sample_count: 1
  conditions:
  - Kilquist syndrome
  - homozygous SLC12A2 deletion
  publication: PMID:30740830
  evidence:
  - reference: PMID:30740830
    reference_title: "Kilquist syndrome: A novel syndromic hearing loss disorder caused by homozygous deletion of SLC12A2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Herein we describe a child admitted to the NIH Undiagnosed Diseases Program with global developmental delay, sensorineural hearing loss, gastrointestinal abnormalities, and absent salivation.
    explanation: >-
      This supports the publication as the foundational disease-defining human
      phenotype dataset for Kilquist syndrome.
notes: >-
  Asta deep research was run as requested, but final curation relied on direct
  review of PubMed references because the retrieval output was noisy and only
  partially disease-specific. The entry is intentionally scoped to biallelic
  Kilquist syndrome / OMIM 619080, with phenotypic claims treated as case-based
  because only a small number of molecularly confirmed biallelic cases have been
  reported. Heterozygous or de novo SLC12A2-related cochleovestibular and
  neurodevelopmental disorders are documented separately as a differential
  scope issue rather than as Kilquist syndrome subtypes.
📚

References & Deep Research

Deep Research

1
Asta
Asta Literature Retrieval: Pathophysiology and clinical mechanisms of Kilquist syndrome. Core disease mechanisms, molecular and cellular pathway...
Asta Scientific Corpus Retrieval 19 citations 2026-04-11T16:00:24.879446

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of Kilquist syndrome. Core disease mechanisms, molecular and cellular pathway...

This report is retrieval-only and is generated directly from Asta results.

  • Papers retrieved: 19
  • Snippets retrieved: 20

Relevant Papers

[1] Precision Therapeutics in Lennox–Gastaut Syndrome: Targeting Molecular Pathophysiology in a Developmental and Epileptic Encephalopathy

  • Authors: Debopam Samanta
  • Year: 2025
  • Venue: Children
  • URL: https://www.semanticscholar.org/paper/455479c1bfbea7b90b73c109228f67c813d13888
  • DOI: 10.3390/children12040481
  • PMID: 40310132
  • PMCID: 12025602
  • Citations: 19
  • Influential citations: 1
  • Summary: A narrative review explores precision therapeutic strategies for LGS based on molecular pathophysiology, including channelopathies, receptor and ligand dysfunction, receptor and ligand dysfunction, cell signaling abnormalities, cell signaling abnormalities, synaptopathies, and the repurposing of existing medications with mechanism-specific effects.
  • Evidence snippets:
  • Snippet 1 (score: 0.400) > Lennox–Gastaut syndrome (LGS) is a severe childhood-onset developmental and epileptic encephalopathy characterized by multiple drug-resistant seizure types, cognitive impairment, and distinctive electroencephalographic patterns. Current treatments primarily focus on symptom management through antiseizure medications (ASMs), dietary therapy, epilepsy surgery, and neuromodulation, but often fail to address the underlying pathophysiology or improve cognitive outcomes. As genetic causes are identified in 30–40% of LGS cases, precision therapeutics targeting specific molecular mechanisms are emerging as promising disease-modifying approaches. This narrative review explores precision therapeutic strategies for LGS based on molecular pathophysiology, including channelopathies (SCN2A, SCN8A, KCNQ2, KCNA2, KCNT1, CACNA1A), receptor and ligand dysfunction (GABA/glutamate systems), cell signaling abnormalities (mTOR pathway), synaptopathies (STXBP1, IQSEC2, DNM1), epigenetic dysregulation (CHD2), and CDKL5 deficiency disorder. Treatment modalities discussed include traditional ASMs, dietary therapy, targeted pharmacotherapy, antisense oligonucleotides, gene therapy, and the repurposing of existing medications with mechanism-specific effects. Early intervention with precision therapeutics may not only improve seizure control but could also potentially prevent progression to LGS in susceptible populations. Future directions include developing computable phenotypes for accurate diagnosis, refining molecular subgrouping, enhancing drug development, advancing gene-based therapies, personalizing neuromodulation, implementing adaptive clinical trial designs, and ensuring equitable access to precision therapeutic approaches. While significant challenges remain, integrating biological insights with innovative clinical strategies offers new hope for transforming LGS treatment from symptomatic management to targeted disease modification.
  • Snippet 2 (score: 0.399) > A key advantage of disease-modifying therapies is their potential to target pathogenic mechanisms early in the disease course, potentially preventing the progression of some infantile epileptic encephalopathies to LGS. > This narrative review explores precision therapeutic strategies based on specific monogenic causes and disease mechanisms relevant to LGS. A comprehensive literature search (PubMed, MEDLINE, ClinicalTrials.gov, conference abstracts from the American Academy of Neurology and American Epilepsy Society, and gray literature) was conducted through 19 February 2025 to identify established ASMs, repurposed and novel drugs, as well as various gene therapy approaches with potential relevance to LGS. Given that over 900 monogenic causes of DEEs have been identified-implicating diverse cellular components such as ion channels, receptors, synaptic proteins, signaling pathways, metabolic processes, and epigenetic regulators-this review discusses current and emerging precision therapeutics based on shared molecular mechanisms and the pathophysiology of select genes associated with LGS [17] (Table 1).

[2] Changes in Serum Proteomic Profiles at Different Stages of Pregnancy Toxemia in Goats

  • Authors: M. Uzti̇mür, C. N. Ünal, Gurler Akpinar
  • Year: 2025
  • Venue: Journal of Veterinary Internal Medicine
  • URL: https://www.semanticscholar.org/paper/4b9c488b5dbd65d7b26fd2ad9aed70e8c4b59942
  • DOI: 10.1111/jvim.70139
  • PMID: 40492724
  • PMCID: 12150350
  • Summary: Understanding the serum proteome profiles of goats with pregnancy toxemia might help identify the proteomes and pathways responsible for the development of this disease and improve diagnosis and treatment.
  • Evidence snippets:
  • Snippet 1 (score: 0.396) > The pathophysiology and progression of this disease are not fully understood. > Traditional biomedical research has focused on the analysis of single genes, proteins, metabolites, or metabolic pathways in diseases. This molecular reductionist approach is based on the assumption that identifying genetic variations and molecular components will lead to new treatments for diseases [13][14][15][16]. However, many diseases are complex and multifactorial, and in order to determine the phenotype of such diseases, it is necessary to understand the changes that occur in more than one gene, pathway, protein, or metabolite at the cellular, tissue, and organismal levels [17][18][19]. Therefore, in recent years, proteomics, as one field of multi-omics technologies, has helped in evaluating the complex pathogenetic mechanisms of different diseases from a broad perspective and has made substantial contributions [20,21]. In veterinary medicine, proteomic analysis of metabolic diseases such as ketosis [16], hypocalcemia [22], and fatty liver [23] in dairy cows has contributed valuable insights for the definition of new pathophysiological pathways and new diagnosis and treatment protocols for these diseases. The proteomic approach can contribute importantly to a broad and detailed understanding of the changes that occur at the organismal level associated with the increase in BHBA concentration in goats with pregnancy toxemia. Our aim was to evaluate the serum protein profiles of goats with SPT or CPT using proteomic techniques to determine the proteomic profiles of these animals and to identify the relevant pathophysiological mechanisms.

[3] Clinical Phenotypes of Cardiovascular and Heart Failure Diseases Can Be Reversed? The Holistic Principle of Systems Biology in Multifaceted Heart Diseases

  • Authors: K. Lourida, G. Louridas
  • Year: 2022
  • Venue: Cardiogenetics
  • URL: https://www.semanticscholar.org/paper/3960806730c4c1115f527e22d6d0a76536570ec5
  • DOI: 10.3390/cardiogenetics12020015
  • Citations: 4
  • Influential citations: 1
  • Summary: Only by understanding the complexity of chronic heart diseases and explaining the interrelationship between different interconnected biological networks can the probability for clinical phenotypes reversal be increased.
  • Evidence snippets:
  • Snippet 1 (score: 0.387) > Treatment with ACEIs, ARBs, and β-blockers impedes deterioration of myocardial function as well as clinical deterioration caused by the deleterious impact of the compensatory systems [58,59]. Therefore, the therapy with ACEIs, ARBs, and β-blockers is the appropriate therapy to block LV remodeling and HF progression and reduce symptoms and/or mortality [55]. > In general, the HF syndrome demonstrates a modular construction with predictable behavior of functional clinical phenotypes having a strong impact on biological networks from epigenetic, cellular to regulatory systems [18]. The importance of individual genes for the pathogenesis and clinical progression of the HF syndrome is restricted to the hypertrophic and dilated cardiomyopathies. It seems that some HF patients have a complex multigenic inheritance, but the importance of individual genes is limited. In contrast, the significant role of epigenetics, proteomics, and metabolomics is increased; but, the complete genetic network system and the interactions between multiomics systems are still uncertain [60]. Multimodal systems that include genetic networks, multiomics, metabolic pathways, environmental factors, and sophisticated disease-related clinical networks are required to be integrated and provide a new holistic and realistic picture. > Significant breakthroughs have been made to understand many of the pathophysiological mechanisms of HFrEF but the natural pathophysiological history and clinical progression of HFpEF still remains inadequately defined [39]. The subclinical progression of pre-clinical diastolic dysfunction (PDD) of LV "to clinical phenotype of HFpEF and the further clinical progression to some more complex clinical models with multi-organ involvement . . . continue to be poorly understood" [40]. Prospective studies are expected to clarify the natural history and clinical progression of HFpEF and define the LV remodeling mechanisms involved. The pathophysiology of LV systolic dysfunction is different to the diastolic dysfunction, as systolic dysfunction is considered a disease of calcium handling and diastolic dysfunction is regarded as a disease of increased myofilament sensitivity to calcium [61][62][63].

[4] Towards Mutation-Specific Precision Medicine in Atypical Clinical Phenotypes of Inherited Arrhythmia Syndromes

  • Authors: T. Nakajima, S. Tamura, M. Kurabayashi, Y. Kaneko
  • Year: 2021
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/3d299f57f344d42eff9d3565d1581dae7fb87a54
  • DOI: 10.3390/ijms22083930
  • PMID: 33920294
  • PMCID: 8069124
  • Citations: 6
  • Influential citations: 1
  • Summary: Since the epileptic phenotype appears to manifest prior to cardiac events in this mutation carrier, identifying KCND3 mutations in patients with epilepsy and providing optimal therapy will help prevent sudden unexpected death in epilepsy.
  • Evidence snippets:
  • Snippet 1 (score: 0.386) > Recent advances in molecular genetics have identified many causal genes for inherited arrhythmia syndromes (IASs) such as long QT syndrome (LQTS) [1], short QT syndrome (SQTS) [2], Brugada syndrome (BrS) [3,4] and early repolarization (ER) syndrome (ERS) [3,5]. Most causal genes for IASs encode cardiac ion channels or their related proteins. Genotype-phenotype studies and functional analyses of mutant genes, using heterologous expression systems and experimental animal models, have revealed the pathophysiology of IASs and enabled the establishment of causal gene-specific precision medicine [6][7][8]. Furthermore, analyses of patient-specific and/or genome-edited induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) have provided further insights into the pathophysiology of IASs and novel promising therapeutic strategies for IASs, although there are still some limitations of using iPSC-CMs, such as immature structure and function and mixed population of atrial, ventricular, and nodal cells, as a standard technology [9]. > The altered function of causal genes that encode cardiac ion channels is caused by multiple mechanisms, including trafficking defects, producing non-functional channels, altered channel gating properties, and a combination thereof. These altered functions of mutant channels underly the clinical phenotypes of IASs [10][11][12]. Particularly, unique electrophysiological properties of mutant channels have been shown to be associated with the atypical clinical phenotypes of IASs [10,13]. Furthermore, the elucidation of the mechanisms underlying the atypical clinical phenotypes of IASs has raised the possibility of mutation-specific precision medicine. > We herein review the current knowledge of genotype-phenotype relationships, underlying molecular and cellular mechanisms, and established pharmacological therapies of IASs, including LQTS, SQTS, and J wave syndrome (BrS and ERS).

[5] New therapeutic targets in rare genetic skeletal diseases

  • Authors: M. Briggs, Peter A. Bell, M. Wright, K. A. Pirog
  • Year: 2015
  • Venue: Expert Opinion on Orphan Drugs
  • URL: https://www.semanticscholar.org/paper/1363107f71ae6d2d60abca471cddf3da5d13644b
  • DOI: 10.1517/21678707.2015.1083853
  • PMID: 26635999
  • PMCID: 4643203
  • Citations: 37
  • Influential citations: 1
  • Summary: An overview of disease mechanisms that are shared amongst groups of different GSDs and potential therapeutic approaches that are under investigation are described to generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.
  • Evidence snippets:
  • Snippet 1 (score: 0.385) > proteins of the cartilage ECM such as type II collagen [50]. However, emerging knowledge suggests that the primary genetic defect may be less important than the cells' response to the expression of the mutant gene product [107]. Moreover, the largely overlooked response of a cell (i.e. chondrocyte) to the abnormal extracellular environment is also important for disease progression as illustrated by several GSDs discussed in this review. > It is important that 'omics'-based approaches and technologies are systematically applied to the study of rare GSDs so that definitive reference profiles and disease signatures are generated for each phenotype. These can then be used in a Systems Biology approach to identify both common and dissimilar pathological signatures and disease mechanisms. This approach is entirely dependent upon relevant in vitro and in vivo models (and also novel 'disease-mechanism phenocopies' [107]) for testing new diagnostic and prognostic tools and for determining the molecular mechanisms that underpin the pathophysiology so that effective therapeutic treatments can be developed and validated. This approach will eventually lead to personalized treatments and care strategies centred on shared disease mechanisms with the use of relevant biomarkers to monitor the efficacy of treatment and disease progression. > It is vital that all relevant stakeholders are involved from the outset in defining the appropriate outcomes of any potential therapeutic regime. The perceptions of a successful therapy can differ widely between the clinical academic community and the relevant patient-support groups and it is vital that there is engagement on all these issues. > In summary, the identification of causative genes and mutations for GSDs over the last 20 years, coupled with the generation and in-depth analysis of a plethora of relevant cell and mouse models, has derived new knowledge on disease mechanisms and suggested potential therapeutic targets. The fast-evolving hypothesis that clinically disparate diseases can share common disease mechanisms is a powerful concept that will generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.

[6] Pharmacogenomic characterization of gemcitabine response – a framework for data integration to enable personalized medicine

  • Authors: Michael Harris, K. Bhuvaneshwar, Thanemozhi Natarajan, L. Sheahan, Difei Wang et al.
  • Year: 2013
  • Venue: Pharmacogenetics and Genomics
  • URL: https://www.semanticscholar.org/paper/1382ddf84b87736a73c2f2f81164ca876c29f4c4
  • DOI: 10.1097/FPC.0000000000000015
  • PMID: 24401833
  • PMCID: 3888473
  • Citations: 16
  • Summary: This in-silico study identified gene variants significantly associated with gemcitabine response that may help to personalize treatment in the clinic and gain insights into drug response mechanisms and to facilitate clinical trial design and regulatory reviews.
  • Evidence snippets:
  • Snippet 1 (score: 0.384) > Understanding the genetic and molecular mechanisms underlying complex diseases such as cancer is extremely challenging. Genome-wide association studies (GWAS) have been extensively used in the past decade to discover important genetic variants. However, the identified SNPs explain only a small proportion of the phenotypic variation, and the predictive power of these SNPs remains low for many complex diseases [10]. To fully elucidate genetic underpinnings of disease a systems biology approach is necessary to characterize variants, mRNA, copy number, proteins, and metabolites, as well as their cellular interactions [11]. Gene set and pathway association analyses are playing an increasingly important role in explaining disease mechanisms through the identification of functional genetic interactions [12]. Many gene-disease association analyses are based on SNP genotype profiling or gene expression studies. However, SNPs can influence many downstream processes including the expression levels of multiple genes and/or protein levels, and variations in expression levels can directly or indirectly impact disease progression and even drug response [13]. An integrative approach combining multiple data types can more accurately capture pathway associations [12] for discovery of clinically actionable variants. > Statistical approaches commonly used to associate variants with disease and/or drug response Fisher's exact test (FET) is commonly used in the association of germline polymorphisms with drug response [14]. The use of probabilistic networks in conjunction with traditional statistical models for mining relationships and associations from genotype-phenotype data is well established [15]. Probabilistic network methods for pharmacogenomics and newer methods such as the Markov Blanket concept may be helpful to better analyze these complex genotype-phenotype associations [16]. Considering the complexity of both cancer prognosis and individual drug response to chemotherapeutics, application of these association methods in conjunction with novel informatics and data integration approaches is necessary to identify clinically relevant variants for validation studies and ultimately testing in the clinic for pharmacogenomics applications.

[7] Human Dermal Fibroblast: A Promising Cellular Model to Study Biological Mechanisms of Major Depression and Antidepressant Drug Response

  • Authors: P. Mesdom, R. Colle, É. Lebigot, S. Trabado, Eric Deflesselle et al.
  • Year: 2020
  • Venue: Current Neuropharmacology
  • URL: https://www.semanticscholar.org/paper/79368e365458486de96794333613c12a6063bf54
  • DOI: 10.2174/1570159X17666191021141057
  • PMID: 31631822
  • PMCID: 7327943
  • Citations: 12
  • Summary: This review highlights the great and still underused potential of HDF, which stands out as a very promising tool in the understanding of MDD and AD mechanisms of action.
  • Evidence snippets:
  • Snippet 1 (score: 0.381) > Background: Human dermal fibroblasts (HDF) can be used as a cellular model relatively easily and without genetic engineering. Therefore, HDF represent an interesting tool to study several human diseases including psychiatric disorders. Despite major depressive disorder (MDD) being the second cause of disability in the world, the efficacy of antidepressant drug (AD) treatment is not sufficient and the underlying mechanisms of MDD and the mechanisms of action of AD are poorly understood. Objective The aim of this review is to highlight the potential of HDF in the study of cellular mechanisms involved in MDD pathophysiology and in the action of AD response. Methods The first part is a systematic review following PRISMA guidelines on the use of HDF in MDD research. The second part reports the mechanisms and molecules both present in HDF and relevant regarding MDD pathophysiology and AD mechanisms of action. Results HDFs from MDD patients have been investigated in a relatively small number of works and most of them focused on the adrenergic pathway and metabolism-related gene expression as compared to HDF from healthy controls. The second part listed an important number of papers demonstrating the presence of many molecular processes in HDF, involved in MDD and AD mechanisms of action. Conclusion The imbalance in the number of papers between the two parts highlights the great and still underused potential of HDF, which stands out as a very promising tool in our understanding of MDD and AD mechanisms of action

[8] Therapies for Mitochondrial Disease: Past, Present, and Future

  • Authors: Megan Ball, Nicole J. Van Bergen, A. Compton, David R Thorburn, S. Rahman et al.
  • Year: 2025
  • Venue: Journal of Inherited Metabolic Disease
  • URL: https://www.semanticscholar.org/paper/196ee50a950f29bc4134cfb8fe6bdfa9a3a1468b
  • DOI: 10.1002/jimd.70065
  • PMID: 40714961
  • PMCID: 12301291
  • Citations: 2
  • Summary: The latest developments in the pursuit to identify effective treatments for mitochondrial disease are examined and the barriers impeding their success in translation to clinical practice are discussed.
  • Evidence snippets:
  • Snippet 1 (score: 0.375) > Mitochondrial disease is a diverse group of clinically and genetically complex disorders caused by pathogenic variants in nuclear or mitochondrial DNA‐encoded genes that disrupt mitochondrial energy production or other important mitochondrial pathways. Mitochondrial disease can present with a wide spectrum of clinical features and can often be difficult to recognize. These conditions can be devastating; however, for the majority, there is no targeted treatment. In the last 60 years, mitochondrial medicine has experienced significant evolution, moving from the pre‐molecular era to the Age of Genomics in which considerable gene discovery and advancement in our understanding of the pathophysiology of mitochondrial disease have been made. In the last decade, in response to the urgent need for effective treatments, a wide range of emerging therapies have been developed, driven by innovative approaches addressing both the genetic and cellular mechanisms underpinning the diseases. Emerging therapies include dietary intervention, small molecule therapies aimed to restore mitochondrial function, stem cell or liver transplantation, and gene or RNA‐based therapies. However, despite these advances, translation to clinical practice is complicated by the sheer genetic and clinical complexity of mitochondrial disease, difficulty in efficient and precise delivery of therapies to affected tissues, rarity of individual genetic conditions, lack of reliable biomarkers and clinically relevant outcome measures, and the dearth of natural history data. This review examines the latest developments in the pursuit to identify effective treatments for mitochondrial disease and discusses the barriers impeding their success in translation to clinical practice. While treatment for mitochondrial disease may be on the horizon, many challenges must be addressed before it can become a reality.

[9] 18O-assisted dynamic metabolomics for individualized diagnostics and treatment of human diseases

  • Authors: E. Nemutlu, Song Zhang, N. Juranic, A. Terzic, S. Macura et al.
  • Year: 2012
  • Venue: Croatian Medical Journal
  • URL: https://www.semanticscholar.org/paper/880f053c7f060db4b990e447d0a22c4b69372ddb
  • DOI: 10.3325/cmj.2012.53.529
  • PMID: 23275318
  • PMCID: 3541579
  • Citations: 28
  • Summary: The potential use of dynamic phosphometabolomic platform for disease diagnostics currently under development at Mayo Clinic is described and discussed briefly.
  • Evidence snippets:
  • Snippet 1 (score: 0.375) > Living cells represent an integrated and interacting network of genes, transcripts, proteins, small signaling molecules, and metabolites that define cellular phenotype and function. Traditionally the focus of biomedical research was on individual genes, single protein targets, single metabolites, and metabolic or signaling pathways. This "molecular reductionist" paradigm was based on the assumption that identifying genetic variations and molecular components would lead to discovery of cures for human diseases. However, most of diseases are complex and multi-factorial and the disease phenotype is determined by the alterations of multiple genes, pathways, proteins and metabolites (at cellular, tissue, and organismal levels). Therefore, an integrated "omics" approach is more viable direction for uncovering alterations in metabolic networks, disease mechanisms, and mechanisms of drug effects. > Recent advent of large-scale metabolomics and fluxomic (metabolite dynamics and metabolic flux analysis) completed the "omics revolution" (Figure 1), where genomics, transcriptomics, proteomics, metabolomics, and fluxomics all together complement phenotype determination of living organism. Such integrated "omics" cascades provide a framework for advances in system and network biology, integrative physiology, and system medicine as well as system pharmacology and regenerative medicine. Noteworthy is the "reverse omic" approach or "metabolomicsinformed pharmacogenomics, " where discovery of specific metabolite changes have led to discovery of genetic alterations (2). Therefore, bringing new "omics" technologies to clinical practice will improve disease diagnostics and treatment by targeting drugs and procedures for each unique transcriptomic and metabolomic profiles.

[10] Modeling psychiatric disorders: from genomic findings to cellular phenotypes

  • Authors: Anna Falk, Vivi M. Heine, A. Harwood, Patrick F. Sullivan, M. Peitz et al.
  • Year: 2016
  • Venue: Molecular Psychiatry
  • URL: https://www.semanticscholar.org/paper/235b41240d78140de7ab06a3ad8a7d0b1bdff1a5
  • DOI: 10.1038/mp.2016.89
  • PMID: 27240529
  • PMCID: 4995546
  • Citations: 77
  • Influential citations: 2
  • Summary: The challenges for modeling of psychiatric disorders, potential solutions and how iPSC technology can be used to develop an analytical framework for the evaluation and therapeutic manipulation of fundamental disease processes are critically reviewed.
  • Evidence snippets:
  • Snippet 1 (score: 0.375) > The key challenge for iPSC-based disease modeling is to identify one or more relevant cellular phenotypes that accurately represent the disease pathophysiology. Increasing numbers of reports have demonstrated that for many diseases specific pathophysiology can be captured in human iPSC-based disease models. These range from cardiovascular disease, 44,45 cancer, 46,47 ocular disease, 48,49 diabetes mellitus 50,51 and neurological disorders of the brain. 52,53 Can the same approach be applied to complex psychiatric disorders? > The problem is that almost all psychiatric disorders are characterized by clinical signs and symptoms, but lack independent verification from objective biomarkers. Thus, how might these clinical phenotypes manifest themselves in terms of cell behavior? The identity of robust cellular 'readouts', which typify any psychiatric disorder, is a crucial unsolved problem and an area of intense study 54 (Table 2). When satisfactorily answered, this will herald a new degree of biological objectivity and quantification for the study of psychiatric disorders. > The aim is to find a single or small number of cell phenotypes or parameters that strongly associate with psychiatric disorders, and establish a cellular profile characteristic of cells derived from the general patient population. Although a consensus set of cellular phenotypes for psychiatric disorder is yet to be established, we can define some of their desired characteristics. First, cellular phenotypes have to relate to the biological pathways identified by genetics. Second, although there are many risk genes in disparate biological pathways, at some level, phenotypes should converge onto a much smaller grouping. Third, phenotypes need to be quantifiable. Finally, to be useful for drug development cellular phenotypes should be reversed by pharmacological treatment, although not necessarily by drugs in current use. > Although human iPSC-based approaches underrepresent the complexity of the human central nervous system, cellular phenotypes are likely to lie more proximal to molecular disease mechanisms than phenotypes seen at the level of a tissue or organism, 55 and thus may bypass compensatory homeostatic (2) Gene expression profiles of SCZ human iPSC neurons identified altered expression of many components of the cyclic AMP and WNT signaling pathways. > (3

[11] Common immunopathogenesis of central nervous system diseases: the protein-homeostasis-system hypothesis

  • Authors: Kyung-Yil Lee
  • Year: 2022
  • Venue: Cell & Bioscience
  • URL: https://www.semanticscholar.org/paper/2984270ae67451b93007040848d9694d19714c9f
  • DOI: 10.1186/s13578-022-00920-5
  • PMID: 36384812
  • PMCID: 9668226
  • Citations: 9
  • Influential citations: 1
  • Summary: This article proposes a common immunopathogenesis of CNS diseases, including prion diseases, Alzheimer’s disease, and genetic diseases, through the PHS hypothesis, which proposes that the immune systems in the host control those substances according to the size and biochemical properties of the substances.
  • Evidence snippets:
  • Snippet 1 (score: 0.366) > There are hundreds of genetic diseases of the CNS. The defective proteins in genetic disorders include structural proteins for neurotransmitter receptors and other receptors or ion channels on CNS cells, and proteins involved in enzymatic process, metabolism (transport), or signal transduction pathways in various communication systems [98]. Because a discussion of each genetic disease is beyond the scope of this review, only crucial points about the pathogenesis of genetic diseases are discussed. Singlegene defect diseases of the CNS can be caused by a defective product from a gene, i.e., a protein deficiency or a malfunctioning protein. In general, autosomal dominant genetic diseases are caused by structural protein defects, and autosomal recessive diseases are caused by defects in enzymatic proteins. However, certain genetic diseases that involve an enzymatic or multifunctional protein defect can induce structural cell injury during the natural course of the illness. > Patients with genetic diseases, including HD, familial JCD, GSS, and the genetic forms of AD and PD, show different clinical manifestations from other affected people in their family, including the time of onset of neurological symptoms, speed of progression of the disease, and prognosis, suggesting that phenotypes can vary even when the genotypes are identical. Likewise, similar phenotypes of CNS symptoms can be found in different genetic diseases. In genetic animal models, the phenotypes of single gene knockout can vary by strain in mice, and the clinical manifestations of a gene defect can differ between mice and humans, and mice null for some genes have also no observable phenotypic abnormalities compared with controls [99]. These findings suggest that default of a protein might be at least partly controlled by individual's control systems and that there might exist a similar immune/repair system against cell injury in genetic diseases. > The pathophysiology of most genetic diseases in the CNS is complex because any affected gene is associated with numerous proteins and their corresponding activations of genes and epigenetic changes that occur during disease processes. Thus, the use of a genetic marker for diagnosing or predicting a prognosis remains impractical in clinical settings [100].

[12] Transcriptional profiling of Hutchinson-Gilford progeria patients identifies primary target pathways of progerin

  • Authors: Sandra Vidak, Sohyoung Kim, Tom Misteli
  • Year: 2026
  • Venue: Nucleus
  • URL: https://www.semanticscholar.org/paper/4bd99b0875508364d8672b6da5a50d024d485a53
  • DOI: 10.1080/19491034.2025.2611484
  • PMID: 41489464
  • PMCID: 12773485
  • Summary: To probe the clinical relevance of previously implicated cellular pathways and to address the extent of gene expression heterogeneity between patients, transcriptomic analysis of a comprehensive set of HGPS patients finds misexpression of several cellular pathways, including multiple signaling pathways, the UPR and mesodermal cell fate specification.
  • Evidence snippets:
  • Snippet 1 (score: 0.362) > Oxidative stress represents another key pathogenic mechanism in HGPS, as impaired NRF2 activity or increased reactive oxygen species (ROS) levels are sufficient to recapitulate HGPSassociated phenotypes [17,32,60]. Collectively, these findings underscore the multifactorial nature of HGPS pathogenesis, implicating interconnected signaling cascades involved in inflammation, oxidative stress, proteostasis, and vascular remodeling. Reassuringly, our findings indicate that many of the major pathways that have been described to contribute to HGPS phenotypes in mouse and cellular disease models are also misregulated in progeria patients, and targeting these pathways may provide therapeutic avenues to mitigate disease severity and improve outcomes in HGPS. > Although individuals with HGPS typically exhibit a characteristic set of clinical features, such as craniofacial abnormalities, growth retardation, and cardiovascular complications, there is notable variability in the age of onset, severity, and progression of symptoms between patients [7,9]. At the cellular level, HGPS is associated with several hallmark abnormalities, including nuclear envelope defects, decreased expression of several nuclear proteins and epigenetic marks, mitochondrial dysfunction, and increased cellular senescence [1,11,30,31,61]. These cellular phenotypes also exhibit considerable variation between patients, possibly contributing to differences in clinical outcomes. Our results indicate that even though some degree of transcriptional heterogeneity between the individual patients exists, the majority of patients exhibit misregulation of a set of shared pathways, suggesting that these pathways are universal driver mechanisms in HGPS. Further work is needed to understand the molecular and genetic factors that underlie inter-individual variability in disease expression and progression. > A limitation of pathway analysis of HGPS patient samples is to distinguish the pathways which are directly targeted by the disease-causing progerin protein and the emergence of adaptive secondary response pathways during progression of the disease in patients during their lifetime. The same caveat applies to the use of cell-based models used in the study of HGPS disease mechanisms.

[13] Molecular genetic basis of epidermolysis bullosa

  • Authors: Y. Kotalevskaya, V. Stepanov
  • Year: 2023
  • Venue: Vavilov Journal of Genetics and Breeding
  • URL: https://www.semanticscholar.org/paper/720cbefbd0435504a6ed670ccf4f491dfbd3f143
  • DOI: 10.18699/VJGB-23-04
  • PMID: 36923479
  • PMCID: 10009482
  • Citations: 8
  • Influential citations: 2
  • Summary: The study of clinical, genetic and ultrastructural changes in EB has significantly expanded the understanding of the natural history of the disease and supplemented the data on genotype-phenotype correlations, promotes the search and study of epigenetic and non-genetic disease modifier factors, and also allows developing approaches to radical treatment of the Disease.
  • Evidence snippets:
  • Snippet 1 (score: 0.362) > Epidermolysis bullosa (EB) is an inherited disorder of skin fragility, caused by mutations in a large number of genes associated with skin integrity and dermal-epidermal adhesion. Skin fragility is manifested by a decrease in resistance to external mechanical influences, the clinical signs of which are the formation of blisters, erosions and wounds on the skin and mucous membranes. EB is a multisystemic disease and characterized by a wide phenotypic spectrum with extracutaneous complications in severe types, besides the skin and mucous membranes, with high mortality. More than 30 clinical subtypes have been identified, which are grouped into four main types: simplex EB, junctional EB, dystrophic EB and Kindler syndrome. To date, pathogenic variants in 16 different genes are associated with EB and encode proteins that are part of the skin anchoring structures or are signaling proteins. Genetic mutations cause dysfunction of cellular structures, differentiation, proliferation and apoptosis of cells, leading to mechanical instability of the skin. The formation of reduced proteins or decrease in their level leads mainly to functional disorders, forming mild or intermediate severe phenotypes. Absent protein expression is a result of null genetic variants and leads to structural abnormalities, causing a severe clinical phenotype. For most of the genes involved in the pathogenesis of EB, certain relationships have been established between the type and position of genetic variant and the severity of the clinical manifestations of the disease. Establishing an accurate diagnosis depends on the correlation of clinical, genealogical and immunohistological data in combination with molecular genetic testing. In general, the study of clinical, genetic and ultrastructural changes in EB has significantly expanded the understanding of the natural history of the disease and supplemented the data on genotype-phenotype correlations, promotes the search and study of epigenetic and non-genetic disease modifier factors, and also allows developing approaches to radical treatment of the disease. New advances of sequencing technologies have made it possible to describe new phenotypes and study their genetic and molecular mechanisms. This article describes the pathogenetic aspects and genes that cause main and rare syndromic subtypes of EB.

[14] Reporter Alleles in hiPSCs: Visual Cues on Development and Disease

  • Authors: Gustavo Caldeira Cotta, Rachel Castro Teixeira dos Santos, Guilherme Mattos Jardim Costa, S. M. S. N. Lacerda
  • Year: 2024
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/97c75ac1cb93f013fe0e49165fb9cc7d8d1b1c30
  • DOI: 10.3390/ijms252011009
  • PMID: 39456792
  • PMCID: 11507014
  • Summary: This study investigates the state-of-the-art gene-editing techniques tailored for generating reporter alleles in hiPSCs, emphasizing their effectiveness in investigating cellular dynamics and disease mechanisms.
  • Evidence snippets:
  • Snippet 1 (score: 0.361) > hiPSCs created by reprogramming adult somatic cells into a pluripotent state provide a valuable platform for investigating the molecular mechanisms involved in disease progression [159]. The emergence of gene-editing tools like CRISPR/Cas9 has further amplified the potential of hiPSCs by enabling precise genetic modifications to establish disease models and develop cell-based therapies [160]. Researchers can introduce mutations or correct genetic defects in hiPSCs to investigate their effects on developmental pathways and disease phenotypes [161], offering unprecedented insights into the molecular mechanisms underlying human development and disease phenotypes [162]. > The establishment of curated repositories of iPSCs associated with specific diseases, such as Alpha-1 Antitrypsin Deficiency, has been crucial in capturing the phenotypic diversity of patient populations and advancing research in disease pathogenesis [163]. The integration of multi-omics approaches in studying iPSC lines has significantly advanced our understanding of the mutational burden in these cells, enabling better selection of iPSC lines for disease modeling and transplantation therapy [164]. Additionally, gene-editing technologies have enabled the correction of disease-causing mutations in patient-derived iPSCs, offering a platform for generating isogenic control cellular models for studying diseases like osteopetrosis and Huntington's disease [165,166]. These advancements have been pivotal in the development of targeted therapies. > On top of this all, reporter allele technology, an application of gene-editing platforms previously discussed, enhances the utility of hiPSCs [167]. With reporter alleles, researchers can monitor the activation of developmental pathways and pinpoint crucial stages in cell lineage specification and differentiation. In disease models, these reporters offer insights into the impact of mutations or pathogenic conditions on cellular functions and the dynamics of gene expression. This method aids in identifying potential therapeutic targets and evaluating drug efficacy under controlled, reproducible conditions. Ultimately, the integration of reporter alleles in hiPSCs facilitates a seamless connection between fundamental research and clinical applications, enriching our comprehension of intricate biological processes and disease mechanisms. To illustrate this, we trace the evolution from the early days of gene targeting in hiPSCs to recent studies.

[15] Nasopharyngeal Carcinoma Signaling Pathway: An Update on Molecular Biomarkers

  • Authors: W. Tulalamba, T. Janvilisri
  • Year: 2012
  • Venue: International Journal of Cell Biology
  • URL: https://www.semanticscholar.org/paper/307cb9186444d9dad6e2e3b53763be0de76de186
  • DOI: 10.1155/2012/594681
  • PMID: 22500174
  • PMCID: 3303613
  • Citations: 93
  • Influential citations: 5
  • Summary: The molecular signaling pathways in the NPC are discussed for the holistic view of NPC development and progression and the important insights toward NPC pathogenesis may offer strategies for identification of novel biomarkers for diagnosis and prognosis.
  • Evidence snippets:
  • Snippet 1 (score: 0.359) > In the pregenomic eras, highly integrated and complex circuitry of molecular signaling in NPC pathogenesis was only partially understood. Over the past decade, the knowledge of the molecular mechanisms in NPC carcinogenesis has been rapidly accumulated. Dysregulation and abnormal protein expression of molecules in certain signaling pathways involved in cellular functions including proliferation, adhesion, survival, and apoptosis has been demonstrated in the NPC cells. Detailed information on the complex network in signaling pathway leading to a coordinated pattern of gene expression and regulation in NPC will undoubtedly provide important clues to develop novel prognostic and therapeutic strategies for this cancer. Refining molecular markers into clinically relevant assays may assist in the detection of NPC in asymptomatic patients, as well as stage classification and monitoring disease progression and treatments. Furthermore, selective regulation of particular proteins targeting cancer cell proliferation, invasion, and apoptosis is a hopeful prospect for future anticancer therapy that slow disease progression and improve survival.

[16] Chemotherapy and Mechanisms of Resistance in Breast Cancer

  • Authors: A. Oliveira, R. E. Santos, F. F. O. Rodrigues
  • Year: 2012
  • Venue: Unknown venue
  • URL: https://www.semanticscholar.org/paper/502a86d8bcd7208be6f539fcceba631f82f25a7d
  • DOI: 10.5772/24629
  • Summary: The addition of adjuvant polychemotherapy in advanced breast cancer showed gain by controlling survival of micrometastases in patients with lymph nodes affected by cancer or not.
  • Evidence snippets:
  • Snippet 1 (score: 0.359) > The main reasons responsible for treatment failure in cancer patients are the mechanisms of drug resistance and emergence of disseminated disease (Terek et al, 2003). We identified two types of resistance most relevant to BC: primary resistance, which corresponds to the clinical situation where the patient showed no response to therapy, and secondary or acquired resistance in which, initially, there is an observed response and a subsequent failure of the treatment regimen (Kroger et al, 1999). Several mechanisms may cause the phenotype of multidrug resistance to chemotherapy drugs and are well characterized in in vitro experiments, including alterations in systemic pharmacology (pharmacokinetics and metabolism), extracellular mechanisms (tumor environment, multicellular drug resistance), and cellular mechanisms (cellular pharmacology, activation and inactivation of drugs, modification of specific targets and regulatory pathways of apoptosis) (Leonessa et al, 2003, Riddick et al, 2005. Identification of factors that affect cell metabolism, which are related to drug resistance, will enable the identification of which patients are at particular risk of treatment failure. Among the biochemical and molecular mechanisms of drug resistance, we stress: changes in the activity of topoisomerase II, alterations in the DNA repair mechanism, overexpression of P-glycoprotein; high intracellular concentrations of enzymes purification of cellular metabolism -among them enzymes the family of glutathione S-transferases (GSTs) and changes in the mechanisms of signaling via c-Jun N-terminal kinase 1 (JNK1) -and "apoptosis signal-regulating kinase (ASK1) required for activation of the" mitogenactivated protein (MAP kinases) in apoptosis and cellular restoration. These pathways are also mediated by proteins encoded by genes of GSTs (O'Brien, Tew, 1996;Burg, Mulder, 2002, L'Ecuyer et al, 2004). Different response rates to particular chemotherapy regimens, as observed in patient groups with the same biological characteristics and stage, suggest the existence of different mechanisms of drug resistance, probably induced by genetic alterations (Hayes, Pulford, 1995;O'Brien , Tew, 1996;Pakunlu et al, 2003). Among the mechanisms of purification of cellular metabolism involved in the

[17] Epigenetic Insights into Tuberous Sclerosis Complex, Von Hippel–Lindau Syndrome, and Ataxia–Telangiectasia

  • Authors: Gavriel Hadjigavriel, Christina Stylianides, Evangelos Axarloglou, M. Manthou, E. Vakirlis et al.
  • Year: 2025
  • Venue: Epigenomes
  • URL: https://www.semanticscholar.org/paper/5643fde916e6d150423d2be7a32508e11fb6b6f8
  • DOI: 10.3390/epigenomes9020020
  • PMID: 40558831
  • PMCID: 12191455
  • Citations: 1
  • Summary: Current evidence on the epigenetic landscape of these syndromes is consolidated, elucidating how modifications may influence disease behavior and contribute to incomplete genotype–phenotype correlations by integrating epigenetic insights with known molecular pathways.
  • Evidence snippets:
  • Snippet 1 (score: 0.358) > Neurocutaneous syndromes represent a clinically and genetically heterogeneous group of disorders, with tuberous sclerosis complex (TSC), von Hippel–Lindau syndrome (VHL), and ataxia–telangiectasia (A-T) exemplifying some of the most complex entities within this category. These syndromes have traditionally been considered monogenic disorders, caused by germline mutations in tumor suppressor or regulatory genes. However, they exhibit a striking degree of phenotypic variability and divergent clinical trajectories that cannot be fully explained by their underlying genetic alterations alone. Increasingly, epigenetic regulatory mechanisms, such as DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA (ncRNA) activity, are recognized as key modulators of gene expression, cellular differentiation, and tissue-specific function. Disruption of these mechanisms has been implicated in disease pathogenesis, tumorigenesis, and neurodegeneration associated with TSC, VHL, and A-T. Aberrant epigenetic profiles may underlie the observed variability in clinical outcomes, even among individuals with identical mutations. This review consolidates current evidence on the epigenetic landscape of these syndromes, elucidating how these modifications may influence disease behavior and contribute to incomplete genotype–phenotype correlations. By integrating epigenetic insights with known molecular pathways, a more nuanced understanding of disease biology emerges, with potential implications for diagnostic stratification, prognostic assessment, and therapeutic innovation.

[18] “Betwixt Mine Eye and Heart a League Is Took”: The Progress of Induced Pluripotent Stem-Cell-Based Models of Dystrophin-Associated Cardiomyopathy

  • Authors: D. Rovina, Elisa Castiglioni, Francesco Niro, Sara Mallia, G. Pompilio et al.
  • Year: 2020
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/9303acc2a5c14adba1c342a87f27f2ae2a57195d
  • DOI: 10.3390/ijms21196997
  • PMID: 32977524
  • PMCID: 7582534
  • Citations: 3
  • Summary: Cardiovascular cells derived from muscular dystrophy patients’ induced pluripotent stem cells are well suited to mimic dystrophin-associated cardiomyopathy and hold great promise for the development of future fully effective therapies.
  • Evidence snippets:
  • Snippet 1 (score: 0.355) > Since inception, iPSC technology has shown enormous potential to model disease, solving many challenges associated with traditional approaches such as animal and primary cell/tissue models. On the basis of their characteristics, patient-specific iPSCs can provide disease-related cells which may have been previously inaccessible, e.g., neurons and cardiomyocytes. Taking advantage of these intrinsic properties, iPSCs carrying patient-specific mutations can be used to model the molecular mechanisms underlying the disease pathophysiology and screen responses to various types of therapeutics. The phenotype ranges that can be investigated by iPSC models involve a broad range of molecular, metabolic, electrophysiological, and cellular analytic techniques. iPSC disease models have been widely applied to study monogenic disorders that are caused by a single gene mutation [130] and sporadic complex disorders involving multiple or unknown genes [131]. The use of iPSC-based models for the latter disease type is more problematic with respect to monogenic diseases, since the phenotype is often the result of multiple small-effect genetic variants in combination with environmental factors. However, this approach was used to model many different complex diseases including Alzheimer's disease, Parkinson's disease, schizophrenia, and cardiac arrhythmias [132][133][134][135]. Without knowing the detailed underlying genetics, differentiated patient-specific iPSCs could provide disease-relevant cells that carry all the genetic elements implicated in the development of the disease and can be useful to analyze the common mechanisms of disease development. Indeed, patient-specific iPSCs obtained from multiple affected individuals that show similar phenotypes could be comparatively investigated in order to find common altered mechanistic pathways or functional activities. > One of the major issues concerning disease modeling using iPSCs is the relative immaturity of the cells differentiated from iPSCs. On the basis of this observation, iPSC-based models are considered more suitable for disorders with an early onset rather than late onset, for which cellular aging could play a role in the disease phenotype. However, despite their fetal phenotype, iPSC-derived cells have highlighted different phenotypes, suggesting that the pathology starts before the appearance of clinical symptoms, potentially allowing the discovery of novel mechanisms involved in the development of pathology [52,136]. > Recently, in

[19] The contribution of genetic determinants of blood gene expression and splicing to molecular phenotypes and health outcomes

  • Authors: A. Tokolyi, E. Persyn, A. Nath, K. Burnham, J. Marten et al.
  • Year: 2025
  • Venue: Nature Genetics
  • URL: https://www.semanticscholar.org/paper/5435e12fd796fca6db2c0ce1844b6fc252d2d73e
  • DOI: 10.1038/s41588-025-02096-3
  • PMID: 40038547
  • PMCID: 11906350
  • Citations: 11
  • Summary: This study mapped blood gene expression and splicing quantitative trait loci and uncovered gene-regulatory mechanisms at disease loci with therapeutic implications, such as WARS1 in hypertension, IL7R in dermatitis and IFNAR2 in COVID-19.
  • Evidence snippets:
  • Snippet 1 (score: 0.354) > The biological mechanisms through which most nonprotein-coding genetic variants affect disease risk are unknown. To investigate gene-regulatory mechanisms, we mapped blood gene expression and splicing quantitative trait loci (QTLs) through bulk RNA sequencing in 4,732 participants and integrated protein, metabolite and lipid data from the same individuals. We identified cis-QTLs for the expression of 17,233 genes and 29,514 splicing events (in 6,853 genes). Colocalization analyses revealed 3,430 proteomic and metabolomic traits with a shared association signal with either gene expression or splicing. We quantified the relative contribution of the genetic effects at loci with shared etiology, observing 222 molecular phenotypes significantly mediated by gene expression or splicing. We uncovered gene-regulatory mechanisms at disease loci with therapeutic implications, such as WARS1 in hypertension, IL7R in dermatitis and IFNAR2 in COVID-19. Our study provides an open-access resource on the shared genetic etiology across transcriptional phenotypes, molecular traits and health outcomes in humans (https://IntervalRNA.org.uk). > The majority of genetic variants associated with common diseases and other complex traits identified through genome-wide association studies (GWAS) lie in nonprotein-coding sequences 1 . Consequently, the molecular mechanisms that underpin many of these genotype-phenotype associations are unclear. Molecular quantitative trait locus (QTL) mapping studies, which identify genetic determinants of transcript, protein or metabolite abundance, can address this knowledge gap by identifying the molecular intermediaries that mediate genetically driven disease risk. These studies can provide specific hypotheses for functional validation experiments 2,3 . > Molecular QTL data can be used for a range of biomedical applications. For example, they have the potential to identify and validate new therapeutic targets and pathways, inform about the biological mechanisms of drug action and safety, highlight new therapeutic indications and reveal clinically relevant biomarkers [4][5][6] . > Many previous studies have carried out QTL mapping within a single molecular domain such as gene or protein expression [7][8][9][10][11][12] .

Notes

  • This provider combines search_papers_by_relevance with snippet_search.
  • No synthesis or second-stage model call is performed.