Genetics of split hand and split foot. A case study

Split hand and split foot is an autosomal dominant disorder that displays several genetic phenomena. These include variable expressivity, reduced penetrance, and segregation distortion. Although not fully understood at the molecular level, all are important in determining transmission of the gene thought to be mapped to the long arm of chromosome 7 (7q21.3-q22.1). These phenomena, therefore, have significant implications for inheritance of split hand and split foot and for proper referral for genetic counseling.