Polydactyly: A study of a four generation Egyptian family

Abstract

Background: Polydactyly is a musculoskeletal anomaly characterized by presence of extra digit or extra digits. It may be isolated, combined or syndromic. According to anatomical site of extra digit polydactyly may be preaxial, postaxial or central. Objective: The aim of the present work is to describe pattern, type and determine the possible mode of inheritance of polydactyly in an affected Egyptian family across different generations and evaluate its variation from other populations. Patient and Methods: The extra digit of the affected members were examined by inspection to determine its site (preaxial or postaxial), laterality, affected limb and presence or absence of polysyndactyly and tested for mobility and sensation. A pedigree was drawn up and photographs were taken. Results: Examination of this family revealed nine affected members; five were males and 4 were females. Two males and one female were presented with bilateral polydactyly on both limbs. Two males were having bilateral polydactyly confined to foot. One male was presented with bilateral polydactyly of hands only. Two females show polysyndactyly. A case with preaxial type I in left foot was noted. Apart of this anomaly all living family members were clinically free. Conclusion: The present study suggests autosomal dominance pattern of polydactyly in this affected Egyptian family with high penetrance and variable gene expressivity. Polydactyly varies between different populations as it's highly heterogeneous