Prevalence of Duchenne muscular dystrophy in Italy: a nationwide survey.

Purpose: The availability of care recommendations has improved survival and delayed the progression of clinical signs in Duchenne muscular dystrophy. The aim of the study was to perform a nationwide survey investigating the prevalence, age distribution, and functional status of Duchenne muscular dystrophyin Italy.

Methods: The survey was performed by collecting data from all 31 reference centers for Duchenne muscular dystrophy in Italy using a structured form. We assessed age distribution, motor function, and the need for respiratory and nutritional support to evaluate their prevalence in different age and functional subgroups.

Results: The estimated prevalence was 1.65/100,000 (3.4/100,000 males). There were 972 boys and adults with a confirmed diagnosis of Duchenne, of age ranging between 6 months and 48 years (mean = 16.5). Over 59% were below the age of 18 years and the remaining 41% were adults. Over 43% were ambulant and 57% non-ambulant; 14.7% were steroids naive (mean 20.6 years), 75% are currently on steroids (mean 14.6 years) with 604 on the daily regime, 126 intermittent. Nearly 73% did not require any ventilatory support, 16% had NIV ≤ 12 h, 9% > 12 h, and 1.4% had a tracheostomy. More than 82% did not require any nutritional support, 13% required food modification/semisolid and 4.4% had a G-tube.

Conclusions: Our findings provide information to be used not only for epidemiological purposes but also for possible trial design to include older non-ambulant patients who until recently have been excluded and for whom clinical information is limited. What is Known • Duchenne muscular dystrophy is a progressive disorder associated with reduced survival. • As part of the disorder there is also a progressive loss of important milestones, including loss of ambulation, and increased need for respiratory and nutritional support. What is New • Our nationwide survey provides prevalence, age distribution, and functional status for Duchenne muscular dystrophyin Italy including both boys and adults. • Our findings can be used for epidemiological purposes and for possible trial design.