| domain | established finding | evidence type/strength | ontology/database annotation |
|---|---|---|---|
| Disease identity | Ultra-rare Mendelian syndrome characterized by autism/neurodevelopmental impairment, epilepsy/seizures, and congenital arthrogryposis with skeletal abnormalities; represented in Orphanet as Autism spectrum disorder-epilepsy-arthrogryposis syndrome (Orphanet 370943) and linked to SLC35A3 (pqac-00000000, pqac-00000001, pqac-00000007) | Curated disease database association plus review synthesis of primary case reports; moderate | Orphanet: 370943; disease label: SLC35A3-CDG / autism spectrum disorder-epilepsy-arthrogryposis syndrome |
| Causal gene | Causal gene is SLC35A3, encoding a Golgi nucleotide-sugar transporter with UDP-GlcNAc transport activity (pqac-00000000, pqac-00000003) | Strong molecular and disease-association evidence; human disease and transporter biology | Gene: SLC35A3; protein class: solute carrier family 35; pathway theme: Golgi glycosylation |
| Inheritance | Reported human disease is autosomal recessive due to biallelic pathogenic variants in SLC35A3 (pqac-00000001, pqac-00000007) | Human case-based evidence summarized in reviews; moderate | Inheritance: autosomal recessive |
| Epidemiology | Twelve patients have been reported, including a large kindred with eight patients and two siblings; no reliable population prevalence or incidence estimate is available (pqac-00000007) | Review summary of published human cases; moderate for case count, weak for epidemiology | Evidence note: ultra-rare disorder; no population registry estimate |
| Core congenital musculoskeletal phenotype | Predominant problems involve skeleton and joints, especially congenital arthrogryposis mainly affecting hands and feet, short long bones, and broader skeletal defects including vertebral anomalies/CMV-like changes (pqac-00000001, pqac-00000007) | Human clinical evidence with supportive animal/model concordance; moderate-strong | HPO suggestions: Arthrogryposis multiplex congenita; Congenital joint contractures; Short long bones; Vertebral anomaly |
| Craniofacial and growth phenotype | Reported associated features include microcephaly and facial dysmorphism, including retromicrognathy and cleft palate (pqac-00000007) | Human clinical evidence; moderate | HPO suggestions: Microcephaly; Facial dysmorphism; Retrognathia/micrognathia; Cleft palate |
| Neurodevelopmental phenotype | Patients show impaired intellectual/neurodevelopmental development; syndrome name and original disease entity include autism spectrum disorder (pqac-00000001, pqac-00000000) | Human disease reports summarized in reviews and curated database label; moderate | HPO suggestions: Global developmental delay; Intellectual disability; Autism spectrum disorder / autistic behavior |
| Seizure phenotype | Seizures/epilepsy are a recurring core feature; disease severity ranges from mild to profound (pqac-00000001, pqac-00000007) | Human case evidence; moderate | HPO suggestions: Seizure; Epilepsy |
| Natural history / prognosis | Clinical severity ranges from mild to profound; 2 reported deaths occurred at 21 days and 9 years, indicating that severe early-life and childhood mortality can occur (pqac-00000007) | Small-case natural history evidence; limited-moderate | Outcome annotation: variable severity; possible early mortality |
| Molecular mechanism | SLC35A3 is a Golgi UDP-GlcNAc transporter; disease mechanism is impaired Golgi UDP-GlcNAc transport causing abnormal glycosylation, including reduced highly branched N-glycans and likely broader effects on proteoglycans/GAG-related development (pqac-00000003, pqac-00000001) | Strong mechanistic evidence from transporter biology, patient cells, and models | GO/pathway suggestions: UDP-N-acetylglucosamine transport; Golgi apparatus; protein glycosylation; glycosaminoglycan biosynthesis |
| Patient-cell functional evidence | Golgi vesicles isolated from patient fibroblasts showed significantly reduced UDP-GlcNAc transport activity; patient fibroblasts supported a glycosylation defect with reduced highly branched N-glycans on the cell surface (pqac-00000001) | Direct human functional evidence; strong | Cell type: fibroblast; assay class: Golgi vesicle transport / glycosylation profiling |
| Comparative / animal evidence | Bovine SLC35A3 missense variation causes complex vertebral malformation with vertebral defects, arthrogryposis, craniofacial anomalies, and perinatal lethality; Slc35a3-null mice show chondrodysplasia, CMV-like vertebral anomalies, reduced cartilage ECM/proteoglycans, and perinatal lethality (pqac-00000003) | Strong comparative/model support for skeletal-development mechanism | Species/model annotation: cattle natural disease; mouse knockout; phenotype theme: vertebral malformation / chondrodysplasia |
| Cellular models | CRISPR SLC35A3-knockout mammalian cell lines show context-dependent glycosylation effects, supporting a role in Golgi UDP-GlcNAc handling while also suggesting compensatory/alternative transport mechanisms (pqac-00000004, pqac-00000005) | In vitro mechanistic evidence; moderate | Model annotation: CRISPR knockout cell lines (CHO, HEK293T, HepG2) |
| Diagnosis | Recommended diagnosis is direct gene or exome sequencing demonstrating biallelic SLC35A3 variants in a compatible phenotype; functional studies in fibroblasts can support pathogenicity where available (pqac-00000007, pqac-00000001) | Review/guideline-style recommendation supported by human functional evidence; moderate | Diagnostic annotation: exome sequencing; genome/gene sequencing; functional fibroblast testing |
| Treatment | No disease-specific therapy is established; treatment is reported as purely symptomatic/supportive (pqac-00000007) | Review summary; moderate | MAXO-style suggestions: symptomatic treatment; seizure management; orthopedic management; developmental therapies |
| Major evidence gaps | Very small number of published patients, sparse variant-level public detail in available sources, no validated biomarkers or disease-specific therapy, no clinical trials found, and no robust prevalence, penetrance, QoL, or longitudinal natural-history datasets (pqac-00000007, pqac-00000001) | High-confidence gap assessment based on absence/scarcity of evidence; strong for gap statement | Knowledge-base flags: evidence sparse; ultra-rare; natural history unknown; no interventional trials identified |


*Table: This table summarizes the most actionable disease facts for Autism spectrum disorder-epilepsy-arthrogryposis syndrome, focusing on established human findings, mechanism, diagnosis, models, and current evidence gaps. It is designed as a compact knowledge-base artifact with ontology and database mapping cues.*