Molecular characterization of a 14q deletion in a boy with features of Holt-Oram syndrome.

[holt-oram syndrome]

Holt-Oram syndrome , the major "heart -hand " syndrome is defined by the association of radial defects or triphalangeal thumbs and septal heart defects . The transmission is autosomal dominant and the causative gene has been shown to be TBX 5 , located on 12 q 24 .1 , which encodes a transcription factor . Genetic heterogeneity has been suggested by several reports . We identified a 14 (q 23 .3 approximately 24 .2 q 31 .1 ) deletion in a boy presenting severe bilateral asymmetrical radial aplasia , congenital heart defects , and developmental delay . This deletion , whose size could be estimated to be 9 .6 -13 .7 Mb , was shown to be inherited via his mother 's interchromosomal insertion . This is the second report of a chromosome 14 interstitial deletion associated with clinical features of Holt-Oram syndrome . These observations suggest the existence of a new "heart -hand " locus on chromosome 14 q .