Epidemiology of dystrophinopathies in North‐West Tuscany: a molecular genetics‐based revisitation

A molecular genetics‐based epidemiological investigation was carried out in 1997 in the territory of North‐West Tuscany, central Italy, to calculate incidence and prevalence rates of Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). Results were compared with a previous epidemiological study conducted in the same area in 1981, in the pre‐dystrophin era. Routine adoption of methods of molecular diagnosis determined an increase in prevalence of BMD from 1.06×10−5 to 2.42×10−5 inhabitants, while cumulative incidence of DMD was markedly decreased from 23.12×10−5 during the period 1965–1976 to 10.71×10−5 male live births during the period 1977–1994. The combined reduction of DMD/BMD diagnostic error rate and familial recurrence could explain these results, providing the bases for a consistent redefinition of dystrophinopathy carrier frequency in the area considered.