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Start free with EleplanBlepharophimosis-intellectual disability syndrome, SBBYS type
ORPHA:3047Malformation syndrome
Also called Hypothyroidism-dysmorphism-postaxial polydactyly-intellectual disability syndrome · SBBYS variant of Ohdo syndrome · SBBYSS · Say-Barber-Biesecker-Young-Simpson syndrome
What it is
A rare, genetic, multiple congenital anomalies syndrome characterized by the association of a typical facial phenotype with microcephaly associated with congenital hypothyroidism, skeletal involvement (polydactyly, long thumb(s) and long first toe(s), and patellar hypoplasia/agenesis), and some degree of global developmental delay, hypotonia and intellectual disability. Facial features include an immobile mask-like face, severe blepharophimosis and ptosis, tear duct abnormalities, a broad nasal bridge, bulbous nasal tip, small mouth, thin upper lip, hypoplastic teeth and small, low set ears. Renal and genital anomalies, usually cryptorchidism, are often present in affected males. Congenital heart defects and growth delay are variably present.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Antenatal, Infancy, Neonatal
- Inheritance
- Autosomal dominant
- Classified as
- Malformation syndrome
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Very common80–99%
18- Blepharophimosis
- Bulbous nose
- Cryptorchidism
- Global developmental delay
- Hypothyroidism
- Hypotonia
- Intellectual disability
- Long nose
- Low-set ears
- Micrognathia
- Posteriorly rotated ears
- Prominent nose
- Prominent occiput
- Retrognathia
- Severe short stature
- Short palpebral fissure
- Sloping forehead
- Specific learning disability
Common30–79%
23- Abnormality of the antihelix
- Abnormality of the cheek
- Atrial septal defect
- Atrioventricular canal defect
- Bifid uvula
- Bilateral single transverse palmar creases
- Camptodactyly of finger
- Clinodactyly of the 5th finger
- Ectopic thyroid
- Failure to thrive
- Feeding difficulties
- Growth delay
- Joint hypermobility
- Microcephaly
- Patent ductus arteriosus
- Polyhydramnios
- Recurrent respiratory infections
- Seizure
- Submucous cleft hard palate
- Thyroid agenesis
- Thyroid dysgenesis
- Thyroid hypoplasia
- Ventricular septal defect
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Gene
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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