ABSTRACT
Pure distal monosomy of the long arm of chromosome 10 is a rare cytogenetic abnormality. The location and size of the deletions described in this region are variable. Nevertheless, the patients share characteristic facial appearance, variable cognitive impairment and neurobehavioral manifestations. A Minimal Critical Region corresponding to a 600 kb Smallest Region of deletion Overlap (SRO) has been proposed. In this report, we describe four patients with a distal 10q26 deletion, who displayed attention-deficit/hyperactivity disorders (ADHD). One of them had a marked behavioral profile and relatively preserved cognitive functions. Interestingly, the SRO was not included in the deleted segment of this patient suggesting that this deletion could contain candidate genes involved in the control of neurobehavioral functions. One of these candidates was the CALY gene, known for its association with ADHD patients and whose expression level was shown to be correlated with neurobehavioral disturbances in varying animal models. This report emphasizes the importance of the behavioral problems as a cardinal feature of the 10q microdeletion syndrome. Haploinsufficiency of CALY could play a crucial role in the development of the behavioral troubles within these patients.
Subject(s)
Chromosome Deletion , Disruptive, Impulse Control, and Conduct Disorders/diagnosis , Intellectual Disability/diagnosis , Adolescent , Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit Disorder with Hyperactivity/genetics , Child , Chromosomes, Human, Pair 10 , Comparative Genomic Hybridization , Disruptive, Impulse Control, and Conduct Disorders/genetics , Female , Genetic Association Studies , Humans , Intellectual Disability/geneticsABSTRACT
Developmental dyslexia is a heterogeneous syndrome with a phonological core deficit and frequent association with other developmental disorders. Controversies exist about the influence of motor difficulties frequently encountered in dyslexia. According to different theoretical approaches, these motor impairments would reflect either a frequent co-morbid entity or a cerebellar dysfunction that could constitute the causal factor of reading disabilities. The principal aim of this study was to determine the frequency of motor impairments in a population of children with phonological dyslexia and specify possible links with attention deficit. We analysed retrospectively motor and attention abilities of 58 children with phonological dyslexia. An important sub-group of children with dyslexia (40-57% depending on the severity of motor difficulties) presented a motor impairment affecting co-ordination, balance and manual dexterity suggesting a cerebellar dysfunction. There was a significant association between attention deficit and motor impairments, with a specific impact on balance and co-ordination deficits. The comparison of performance in four groups defined according to the presence versus absence of attention deficit and motor impairment, respectively, were not in favour of a unequivocal causal link between reading disabilities and motor or attention disorders.
