Holt-Oram syndrome (HOS) is an autosomal dominant disorder, characterised by congenital heart and upper limb malformations. It is a rare disorder, however, there are several groups working on this syndrome worldwide since the genes involved in this syndrome are important to study on the cardiogenesis and development of hand.Although genetically heterogeneous, HOS is frequently linked to the TBX5 gene. To review the molecular genetics of HOS, this article has been written to highlight the importance of this syndrome and have more attention of pediatricians, cardiologists, heart surgeons, orthopedists and geneticists