Ectrodactyly and tetralogy of Fallot in a fetus with del(6)(q21q23).

We report a fetus with del(6)(q21q23) who had tetralogy of Fallot and ectrodactyly of the right hand. Analysis of the literature showed that both these defects were reported in several patients with similar deletions. The minimal segment responsible for ectrodactyly may be limited to 7.35 Mb (106.650.000-114.600.000). However 1) significant number of patients with this deletion but without ectrodactyly or other defects of extremities, and 2) wide range of unusual birth defects in some persons with deletions of the critical segment allow to propose involvement of regulatory element(s) necessary for the occurrence of ectrodactyly in patients with del 6q21.