Cognition and adaptive skills in myotonic dystrophy type 1: a study of 55 individuals with congenital and childhood forms

Abstract

Aims To investigate cognitive abilities and adaptive skills in children and adolescents with myotonic dystrophy type 1 (DM1) and correlate the findings to the cytosine‐thymine‐guanine (CTG) repeat expansion size. Method Cognitive level was assessed in 55 children and adolescents with DM1 (31 males, 24 females; mean age 12y 1mo, SD 5y 1mo; range 2y 7mo–21y 5mo) divided into the following categories: severe congenital DM1 (n=19), mild congenital DM1 (n=18), and childhood DM1 (n=18). The Griffiths Mental Developmental Scale, the Wechsler Scales, and the Vineland Adaptive Behavior Scales (VABS) for adaptive skills were used for this purpose. Results Learning disability was found in 95% of the severe congenital group, 83% of the mild congenital group, and 89% of the childhood DM1 group. The more severe the form of DM1, the lower the full‐scale IQ (FSIQ; rs=0.28, p=0.044). The individuals with severe congenital and childhood DM1 had a significantly higher verbal IQ than performance IQ (severe congenital: mean difference 5.7, SD 5.7, p=0.008; childhood DM1: mean difference 9.8, SD 18.0, p=0.038). CTG repeat expansion correlated negatively with FSIQ (rs=−0.63, p<0.006). Almost all participants showed poor results on the VABS. There was a positive relationship between cognitive level and adaptive skills in the mild congenital (rs=0.95, p<0.01) and childhood DM1 groups (rs=0.92, p<0.01). Interpretation Children and adolescents with DM1 exhibit significant cognitive and adaptive problems.

Disease burden and functional outcomes in congenital myotonic dystrophy

“…While intellectual impairment and oral facial weakness have been previously reported, this study further evaluates the disease burden associated with CDM. 7,8,10 Specifically, we provide evidence of daytime sleepiness and motor delay that have not been previously reported. The outcome measures used in the study were chosen based on past pilot studies by the authors, recent patient-reported disease burden, and relevant literature focusing on CDM and other pediatric neuromuscular disorders.…”

“…Both intellectual impairment and oral facial weakness cause significant burden during childhood. 7,8 In addition to intellectual impairment, there is evidence of autism spectrum disorder and attention-deficit/hyperactivity disorder. 7,9 A prior cross-sectional survey study identified difficulty with communication and problems with hands and fingers as the issues that reduce quality of life in children.…”

“…7,8 In addition to intellectual impairment, there is evidence of autism spectrum disorder and attention-deficit/hyperactivity disorder. 7,9 A prior cross-sectional survey study identified difficulty with communication and problems with hands and fingers as the issues that reduce quality of life in children. 10 While this work has helped to characterize the disease burden in children with CDM, it did not serially evaluate patients using clinical assessments.…”

The effect of lip strengthening exercises in children and adolescents with myotonic dystrophy type 1

“…Other systems commonly affected are the heart, lungs, smooth muscle, endocrine regulation, and brain [1]. Developmental delay and learning disabilities of varying degrees, are common in the congenital and childhood forms of the disease and the prevalence of neuropsychiatric disorders is higher in this group than in the general population [2,3]. DM1 has an autosomal dominant inheritance pattern and is caused by an expansion of a CTG-repeat sequence (trinucleotide expansion) on chromosome 19q13.…”

Muskelsykdommer med debut i barnealder

“…Ved debut senere er det ofte atferdsvansker og laerevansker som først gjør seg gjeldende (16). Selv om en diagnostisk gentest er lett tilgjengelig, kan det gå lang tid før riktig diagnose blir stilt og barna blir forstått på riktig måte.…”