A contiguous gene deletion syndrome at 7q21-q22 and implications for a relationship between isolated ectrodactyly and syndromic ectrodactyly.

Ectrodactyly is a genetically heterogeneous human limb developmental malformation with an autosomal locus at 7q21 designated SHFD1. We report a patient with ectrodactyly and a small interstitial deletion of 7q21, detected by high resolution karyotype, which provides additional evidence for the existence of an ectrodactyly gene in this region and further restricts the size of the critical region containing SHFD1. A review of previously published patients with ectrodactyly and similar deletions suggests a contiguous gene deletion syndrome at 7q21-q22 which consists of ectrodactyly, growth retardation, developmental delay, hypertelorism, ear malformation, components of the Robin sequence, and GU abnormalities. Moreover, the clinical, genetic, and cytogenetic similarities of a number of multiple congenital anomaly syndromes which include ectrodactyly as just one component lead us to propose that a common genetic basis may underlie many of these syndromes. Thus, evaluation for related physical anomalies and high resolution cytogenetic studies are indicated in patients with ectrodactyly.