Preferred Label : Ohdo syndrome, sbbys variant;
Symbol : SBBYSS;
CISMeF acronym : SBBYSS; YSS;
Type : Phenotype, molecular basis known;
Alternative titles and symbols : Say-barber-biesecker-young-simpson syndrome; Young-simpson syndrome; YSS;
Description : Say-Barber-Biesecker-Young-Simpson syndrome, a variant of Ohdo syndrome (249620),
is characterized by distinctive facial appearance with severe blepharophimosis, an
immobile mask-like face, a bulbous nasal tip, and a small mouth with a thin upper
lip. The condition presents in infancy with severe hypotonia and feeding problems.
Associated skeletal problems include joint laxity, abnormally long thumbs and great
toes, and dislocated or hypoplastic patellae. Structural cardiac defects are present
in around 50% of cases, and dental anomalies, including small and pointed teeth, are
common. Many affected individuals have abnormalities of thyroid structure or function.
YSS is usually associated with severe mental retardation, delayed motor milestones,
and significantly impaired speech (summary by Clayton-Smith et al., 2011). Genitopatellar
syndrome (606170) is an allelic disorder with overlapping features.;
Inheritance : Autosomal dominant;
Molecular basis : Caused by mutation in the lysine acetyltransferase 6B gene (KAT6B, 605880.0001);
Prefixed ID : #603736;
Origin ID : 603736;
UMLS CUI : C1863557;
Currated CISMeF NLP mapping
DO Cross reference
Genes related to phenotype
HPO term(s)
ORDO concept(s)
Semantic type(s)
UMLS correspondences (same concept)