Holt-Oram syndrome also called as
[A] Williams syndrome
[B] Noonan syndrome
[C] Heart-hand syndrome
[D] Shone’s Syndrome
- Congenital heart malformations are present in 75% of individuals with Holt-Oram syndrome
- Most commonly – ostium secundum atrial septal defect (ASD) and ventricular septal defect (VSD).
- Autosomal dominant disorder
- Characterized by upper limb abnormalities in association with congenital heart lesions
- Heterozygous mutation in the TBX5 gene on chromosome 12q24.1 causes Holt-Oram syndrome
- Upper-limb malformations can involve – carpal bones, thenar bones, and radial bones.
- Abnormalities may be unilateral or bilateral and symmetric or asymmetric.
- Most cases are unilateral and affect the left side.
- Thumb may be completely absent, grossly underdeveloped, or triphalangeal.