Insights into the pathogenesis and treatment of split hand foot malformation (cleft hand).

Cleft hand or split hand foot malformation is a sequence of phenotypes, from a minor shortening of the central digit to a complete absence of the third ray and in the most severe cases, absence of two, three or four rays. It is a rare but spectacular presentation usually involving both hands and feet. Inheritance is mostly autosomal dominant but sporadic cases without family history are also reported, resulting from a de novo mutation/deletion/duplication. Intra-familial clinical variability is the rule, with incomplete penetrance. X-linked or autosomal recessive inheritance has also been described. To date, seven subgroups of split hand foot malformation have been identified and seven loci are currently known. Anatomical records have enhanced our knowledge of this group of disorders of the hands and feet and allowed us to improve surgical procedures and long-term outcome.