Are there ethnic differences in deletions in the dystrophin gene?

Abstract

We studied 160 cases of Duchenne muscular dystrophy (DMD) drawn from all parts of India, using multiplex PCR of 27 exons. Of these, 103 (64.4%) showed intragenic deletions. Most (69.7%) of the deletions involved exons 45-51. The phenotype of cases with deletion of single exons did not differ significantly from those with deletion of multiple exons. The distribution of deletions in studies from different countries was variable, but this was accounted for either by the small number of cases studied, or by fewer exons analyzed. It is concluded that there is likely to be no ethnic difference with respect to deletions in the DMD gene.

Genetic and clinical profile of patients of Duchenne muscular dystrophy: Experience from a tertiary care center in Eastern India

“…Our data clearly shows that DMD deletions are inhomogeneously distributed among our patients. Our observation was similar to other studies like Banerjee, et al [20] and Swaminathan, et al [5] where they could not establish any phenotypic and genotype correlation considering the size of exon deletion and pattern of deletion. Moreover, Baumbach, et al [21] and Lindlof, et al [22] found no significant correlation between clinical phenotype and number of exon deletion.…”

Deletional mutations of dystrophin gene and carrier detection in eastern India

“…However, there is no significant difference in the distribution pattern among the four patient groups studied from India (0.25<p<0.5). [17][18][19] As the breakpoints of the deletions lie in introns which are mostly free from selection pressure, sequence divergence, particularly at poly dAdT repeat regions which have been found in junction fragments, are possible and may explain this variation.…”

Intragenic deletions in thedystrophingene in 211 Pakistani Duchenne muscular dystrophy patients

“…24,25 Variations in the incidence of intragenic dystrophin deletions in Indian DMD/ BMD patients are also reported. 26,27 Mallikarjuna et al proposed that the lower incidence of dystrophin intragenic deletions from South India is suggestive of variations in southern and northern populations. 28 The lower deletion rate (40.75%) in the Pakistani population detected in the present study as compared to that in neighboring India is also indicative of genetic difference between these two populations.…”