Omodysplasia is an extremely rare short-limb skeletal dysplasia characterized by 1:
- frontal bossing
- depressed nasal bridge
- anteverted nares
- low-set ears
- long philtrum
- rhizomelia
- short Humerus with hypoplastic distal humeri
- elbow dislocation
- radio-ulnar diastasis
- flared metaphyses
- short 1st metacarpal
- cryptorchidism
It is further divided into two subtypes based on genetic mutations. Type 2 omodysplasia, also known as autosomal dominant omodysplasia, is caused by a mutation in the FZD-2 gene and presents with shortened upper extremities and first metacarpal bones along with facial dysmorphism 2. Type 1 omodysplasia, also known as autosomal recessive omodysplasia caused by a mutation in the GPC6 gene, present with lower limb involvement and severe rhizomelic short stature in addition to craniofacial and skeletal abnormalities of the upper arm 3.
Differential diagnosis
- diastrophic dysplasia, atelosteogenesis, and Larsen syndrome for autosomal recessive form
- robinow syndrome for autosomal dominant form