Developmental delay has been reported in males with Xp21 deletion when the deletion extends proximally to include <i>DMD</i> or when larger deletions extend distally to include <i>IL1RAPL1</i> and <i>DMD.</i>
We report here five cases of CNVs involving the dystrophin gene detected by aCGH in girls referred for developmental delay, without any family history of dystrophinopathy.
Given the familial and therapeutic implications for accurate diagnosis of DMD mutations, this case raises the possible need for screening boys with global developmental delay/intellectual disability even in the absence of any overt muscle weakness and further shows the utility of comparative genomic hybridization (CGH) analysis in the evaluation of patients with nonsyndromic mental retardation.
We speculate that the developmental delay in the expression of dystrophin is a characteristic finding in regenerating fibers from asymptomatic and young BMD patients, such as the siblings in this report.