blepharophimosis - intellectual disability syndrome, SBBYS type
Findings
No curated finding names blepharophimosis - intellectual disability syndrome, SBBYS type yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Blepharophimosis-intellectual disability syndrome, SBBYS type is characterized by the association of congenital hypothyroidism, facial dysmorphism (microcephaly, blepharophimosis, a bulbous nose, thin lip, low-set ears and micrognathia), postaxial polydactyly and severe intellectual deficit. Less than 20 cases have been reported so far. Cryptorchidism is present in affected males. Some patients also have cardiac anomalies (interventricular communication), hypotonia and growth delay. Autosomal recessive inheritance has been suggested.
Definition from the Mondo Disease Ontology (MONDO:0011365), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance
- Onset and course
- Infantile onset
HPO, annotations 2026-09-02
Features
53 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Severe intellectual disabilityHPOHP:0010864
- 19 of 19 reported patients
- Feeding difficultiesHPOHP:0011968
- 18 of 19 reported patients
- Frequent (30% to 79% of cases)
- CryptorchidismHPOHP:0000028
- 8 of 9 reported patients · Male
- Very frequent (80% to 99% of cases)
- HypotoniaHPOHP:0001252
- 16 of 19 reported patients
- Very frequent (80% to 99% of cases)
- BlepharophimosisHPOHP:0000581
- Very frequent (80% to 99% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- KAT6BHGNC:17582
- Definitive · G2P · Autosomal dominant · 2020
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2023
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
Other names
5 names
Resolves to: blepharophimosis - intellectual disability syndrome, SBBYS type
- Also called
- hypothyroidism-dysmorphism-postaxial polydactyly-intellectual disability syndromeOhdo syndrome, SBBYS variantSay-Barber-Biesecker-Young-Simpson syndromeSBBYSSSBBYSS syndrome