A new mutation in the TBX5 gene in Holt-Oram syndrome: two cases in the same family and prenatal diagnosis.

[holt-oram syndrome]

Holt -Oram Syndrome (HOS ) is a rare autosomal dominant condition characterized by anomalies of the upper extremity and cardiac malformations . Mutations in the TBX 5 gene are what cause HOS . The proband is an 8 -year -old male who presented with upper -extremity abnormalities and a chest deformity . He was born to a nonconsanguineous marriage at full term . He has a history of ventricular septal defect . His mother presented with deformation in both hands and forearms , and was 9 weeks ' pregnant . Mutation analysis for TBX 5 gene revealed heterozygous p .L 65 Qfs *10 in both the patient and his mother . Molecular analysis of the fetus was normal for TBX 5 gene in the 13 th week of pregnancy . In conclusion , our case supports the fact that the HOS presents differently , case by case , even within the same family . The novel mutation reported here and phenotypic findings in the affected members may contribute to the phenotype-genotype correlation .