Advances in understanding the genetics of syndromes involving congenital upper limb anomalies

Congenital upper limb anomalies (CULA) are a common birth defect and a significant portion of complicated syndromic anomalies have upper limb involvement. Mostly the mortality of babies with CULA can be attributed to associated anomalies. The cause of the majority of syndromic CULA was unknown until recently. Advances in genetic and genomic technologies have unraveled the genetic basis of many syndromes-associated CULA, while at the same time highlighting the extreme heterogeneity in CULA genetics. Discoveries regarding biological pathways and syndromic CULA provide insights into the limb development and bring a better understanding of the pathogenesis of CULA. The aim of this review is to provide an overview of the genetic basis of syndromic CULA and discuss the role of biological pathways in syndromic CULA.