Autism spectrum conditons in myotonic dystrophy type 1: A study on 57 individuals with congenital and childhood forms

Abstract

Myotonic dystrophy type 1 (DM1) is an autosomal dominant disorder, caused by an expansion of a CTG triplet repeat in the DMPK gene. The aims of the present study were to classify a cohort of children with DM1, to describe their neuropsychiatric problems and cognitive level, to estimate the size of the CTG expansion, and to correlate the molecular findings with the neuropsychiatric problems. Fifty-seven children and adolescents (26 females; 31 males) with DM1 (CTG repeats > 40) were included in the study. The following instruments were used: Autism Diagnostic Interview-Revised (ADI-R), 5-15, Griffiths Mental Development Scales, and the Wechsler Scales. Based on age at onset and presenting symptoms, the children were divided into four DM1 groups; severe congenital (n = 19), mild congenital (n = 18), childhood (n = 18), and classical DM1 (n = 2). Forty-nine percent had an autism spectrum disorder (ASD) and autistic disorder was the most common diagnosis present in 35% of the subjects. Eighty-six percent of the individuals with DM1 had mental retardation (MR), most of them moderate or severe MR. ASD was significantly correlated with the DM1 form; the more severe the form of DM1, the higher the frequency of ASD. The frequency of ASD increased with increasing CTG repeat expansions. ASD and/or other neuropsychiatric disorders such as attention deficit hyperactivity disorder, and Tourette's disorder were found in 54% of the total DM1 group. In conclusion, awareness of ASD comorbidity in DM1 is essential. Further studies are warranted to elucidate the molecular etiology causing neurodevelopmental symptoms such as ASD and MR in DM1.

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

“…Ekströ m et al) 19 . Assessment of gross motor function was made using the Hammersmith functional motor scale, 20 which is widely used to assess motor function in neuromuscular disorders, including DM1.…”

“…10 DNA was extracted from peripheral blood lymphocytes and analysed for expansion of the CTG repeat in the DMPK gene. 19 …”

Disease burden and functional outcomes in congenital myotonic dystrophy

“…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.…”

Oral hygiene aspects in a study of children and young adults with the congenital and childhood forms of myotonic dystrophy type 1

“…The earlier the onset of the disease, the more serious the symptoms (Harper 2001). Intellectual disability and neuropsychiatric disorders are common in congenital and childhood subforms of DM1 (Ekström et al 2008). …”