IEMbase 0385: CHSY1-related Chondroitin sulfate synthase 1 deficiency (CDG)
Scope
| Field | Value |
|---|---|
| IEMbase ID | 385 |
| Nosology | 18.2.09.01 |
| Gene | CHSY1 |
| External IDs | OMIM:605282; ORPHA:363417 |
| Generated mapping | MAPPED; Temtamy_Preaxial_Brachydactyly_Syndrome.yaml |
| Candidate DisMech targets | Temtamy_Preaxial_Brachydactyly_Syndrome.yaml |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents autosomal recessive CHSY1-related chondroitin sulfate synthase 1 deficiency, also listed as CHSY1-CDG and Tentamy preaxial brachydactyly syndrome. The source spelling "Tentamy" appears to be a source label variant for Temtamy.
Clinical rows include abducted thumbs, clinodactyly, hyperphalangism, medial deviation of fingers and toes, preaxial brachydactyly, symphalangism, syndactyly, sensorineural deafness, delta-shaped phalanges, developmental delay, kyphoscoliosis, optic atrophy, pectus excavatum, radioulnar synostosis, tarsal-carpal fusions, and cerebellar vermis agenesis/hypoplasia. There are no biochemical or treatment rows.
DisMech phenotype coverage
The generated mapping to Temtamy_Preaxial_Brachydactyly_Syndrome.yaml is
correct. Local DisMech models biallelic CHSY1 loss of function, impaired
chondroitin sulfate biosynthesis, excess JAG1/NOTCH signaling, BMP and
inner-ear patterning effects, and the preaxial brachydactyly, hyperphalangism,
symphalangism, carpal/tarsal fusion, radioulnar synostosis, hearing loss, short
stature, and developmental-delay phenotype cluster.
Local DisMech is stronger for mechanism and for the distinction between CHSY1-related Temtamy preaxial brachydactyly syndrome and C12orf57-related Temtamy syndrome.
Concordance and completeness
Judgement: correct mapping with high concordance.
The resources agree on CHSY1 identity, autosomal recessive inheritance, preaxial brachydactyly, hyperphalangism, symphalangism, carpal/tarsal and radioulnar fusion findings, hearing loss, and developmental involvement. IEMbase adds a CDG framing and several granular skeletal/ocular/brain prompts.
Curation actions
- Keep the generated mapping to
Temtamy_Preaxial_Brachydactyly_Syndrome.yaml. - Treat "Tentamy" as source metadata/spelling, not as a new disease label.
- Consider future enrichment with abducted thumbs, clinodactyly, medial deviations, kyphoscoliosis, optic atrophy, pectus excavatum, cerebellar vermis agenesis/hypoplasia, and tarsal-carpal fusions after source verification.