Familial progressive sinoatrial and atrioventricular conduction disease of adult onset with sudden death, dilated cardiomyopathy, and brachydactyly. A new type of heart-hand syndrome?

We identified a family with 10 affected members in four generations suffering from adult-onset progressive sinoatrial and atrioventricular conduction disease, sudden death due to ventricular tachyarrhythmia, dilated cardiomyopathy, and a unique type of brachydactyly with mild hand involvement (short distal, middle, proximal phalanges and clinodactyly) and more severe foot involvement (short distal, proximal phalanges and metatarsal bones, short or absent middle phalanges, terminal symphalangism, duplication of the bases of the second metatarsals, extra ossicles, and syndactyly). The phenotype differences from other reported genetic abnormalities and linkage exclusion of Holt-Oram syndrome, ulnar-mammary syndrome, brachydactyly type B or Robinow syndrome, and cardiac conduction disease or Brugada syndrome loci suggest that we report on a new hereditary heart-hand syndrome.