Introduction: Muscular dystrophies are diagnosed by genetic studies and muscle biopsy, the former is expensive and sparingly available while the latter is a time consuming and relatively invasive procedure requiring sedation. A fast, easily available, minimally invasive diagnostic test is required which does not require sedation. Common muscle proteins causing muscular dystrophy have been localized to arrector pili, a dermal smooth muscle.¹This study explored punch skin biopsy as a diagnostic tool in muscular dystrophies (particularly dystrophinopathy) in  a tertiary care hospital in north India from October 2010 to September 2013.

Methods: Muscle biopsy and genetic test (only  for dystrophinopathy) were gold standard investigations. Skin biopsies were subjected to immunohistochemical analysis of dystrophin (1,2,3) sarcoglycan( α,β,γ,δ) dysferlin, emerin, merosin and collagen 6.

Results: In 162 patients with muscular dystrophy, skin biopsy diagnosed dystrophinopathywith a sensitivity, specificity, positive and negative predictive value of 97%, 92.3%, 98.5% and 85.7% respectively. Five (5/5) cases each of sarcoglycanopathy and Ullrich muscular dystrophy (5/5) was also diagnosed correctly by skin biopsy. However 1case each of emerin and merosin deficient muscular dystrophy and dysferlinopathy were not correctly diagnosed by skin biopsy and they showed positive immunostaining in arrector pili ?muscle.

Conclusion: Skin biopsy can be used for screening dystrophinopathy and it should be evaluated in other muscular dystrophies in larger samples. It being a simple and minimally invasive procedure, serial monitoring of histopathological and molecular markers of disease progression can be done. Repeated skin biopsy can be done for evaluating protein rescue in novel treatment trials.²