Cognitive profile in childhood myotonic dystrophy type 1: Is there a global impairment?

• Published in: Neuromuscular disorders : NMD Vol. 17; no. 6; pp. 451 - 458
• Main Authors: Angeard, Nathalie, Gargiulo, Marcela, Jacquette, Aurélia, Radvanyi, Hélène, Eymard, Bruno, Héron, Delphine
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.06.2007
• Subjects: (CTG) n; Adolescent; Age of Onset; Child; Childhood-onset form; Cognition; Cognition Disorders - genetics; Cognitive impairment; Female; Genes, X-Linked - genetics; Genes, Y-Linked - genetics; Humans; Intelligence - genetics; Learning Disorders - genetics; Male; Myotonic dystrophy; Myotonic Dystrophy - genetics; Myotonic Dystrophy - physiopathology; Myotonin-Protein Kinase; Neurology; Protein-Serine-Threonine Kinases - genetics; Transmitting parent’s sex; Trinucleotide Repeat Expansion - genetics; Trinucleotide Repeats - genetics; Myotonic dystrophy; Childhood-onset form; Transmitting parent’s sex; (CTG) n; Cognitive impairment
• ISSN: 0960-8966; 1873-2364
• DOI: 10.1016/j.nmd.2007.02.012

The objective of this study was to assess the cognitive profile in the childhood-onset form of myotonic dystrophy (DM1). We carried out a general cognitive abilities study on 36 patients (6–18 years). Results of Full Scale IQ , VIQ (Verbal IQ) and PIQ (Performance IQ) measures are discussed in terms of global cognitive impairment depending on the (CTG) n repeat size and the transmitting parent’s sex. The results highlighted a negative correlation between the CTG repeat size and cognitive function : (1) 55% of the subjects (20/34) presented large CTG expansion (mean = 761) correlated with significant extensive cognitive deficits (mean Full Scale IQ = 56) in both intelligence scales (verbal and non-verbal) ; most of them exhibited DM1 maternal transmission. (2) In the case of smaller expansion (mean = 527), 38% of the subjects exhibited a subnormal intelligence (mean Full Scale IQ = 86) but performed poorly on subtests evaluating attention/memory function and presented a severe deficit in visuospatial and/or visuo-constructive skills. Most of these children had paternal transmission but a few had an affected mother.