Editors' note: A large multicenter study of pediatric myotonic dystrophy type 1 for evidence-based management

Abstract

In the largest cross-sectional study of children born to parents with myotonic dystrophy type 1 (DM1) to date, Dr. Lagrue et al. reported on the various genetic and clinical features of 314 children to better characterize the disease epidemiology. Among their findings, the investigators observed a higher than expected rate of paternal transmission (12.7% in the congenital form, 42% in the infantile form, and 68.4% in the juvenile form), whereas previous estimates reported a 0%–20% rate of paternal transmission. In keeping with previous studies, however, the investigators observed a high rate of cognitive impairment, with cognitive slowing seen in 83% of children, ADHD in 64%, and two-thirds of patients having deficits in written or spoken language. Arrhythmias were also not uncommon—occurring in 13% of patients—with 1 in 25 children requiring a pacemaker. Drs. Brignol and Bremond-Gignac commented on the important and heterogeneous ocular manifestations as well. They emphasized the value of multidisciplinary care of these patients, particularly given the prevalence of cataracts and other ocular abnormalities. Although the study by Dr. Lagrue et al. is limited to patients evaluated at French neuromuscular centers, their results are likely generalizable to all pediatric patients with DM1, and they may be useful in the clinical care and prognostication of these patients and family planning. In the largest cross-sectional study of children born to parents with myotonic dystrophy type 1 (DM1) to date, Dr. Lagrue et al. reported on the various genetic and clinical features of 314 children to better characterize the disease epidemiology. Among their findings, the investigators observed a higher than expected rate of paternal transmission (12.7% in the congenital form, 42% in the infantile form, and 68.4% in the juvenile form), whereas previous estimates reported a 0%–20% rate of paternal transmission. In keeping with previous studies, however, the investigators observed a high rate of cognitive impairment, with cognitive slowing seen in 83% of children, ADHD in 64%, and two-thirds of patients having deficits in written or spoken language. Arrhythmias were also not uncommon—occurring in 13% of patients—with 1 in 25 children requiring a pacemaker. Drs. Brignol and Bremond-Gignac commented on the important and heterogeneous ocular manifestations as well. They emphasized the value of multidisciplinary care of these patients, particularly given the prevalence of cataracts and other ocular abnormalities. Although the study by Dr. Lagrue et al. is limited to patients evaluated at French neuromuscular centers, their results are likely generalizable to all pediatric patients with DM1, and they may be useful in the clinical care and prognostication of these patients and family planning.