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The majority of cases are due to a common deletion in chromosome 17p In children with SMS, autistic-like behaviors and symptoms start to emerge around 18 months of age. This study included 26 individuals 15 females and 11 maleswith a confirmed deletion del 17p The SCQ scores are consistent to show that a majority of individuals may meet criteria for autism spectrum disorders at some point in their lifetime.
These results suggest that SMS needs to be considered in the differential diagnosis of autism spectrum disorders but also that therapeutic interventions for autism are likely to benefit individuals with SMS.
The mechanisms by which the deletion of RAI1 and contiguous genes cause psychopathology remain unknown but they provide a solid starting point for further studies of gene-brain-behavior interactions in SMS and autism spectrum disorders.
Smith-Magenis syndrome SMS; OMIM is a neurodevelopmental disorder characterized by a well-defined pattern of anomalies including a distinct craniofacial dysmorphic phenotype, abnormalities of sleep-wake circadian rhythm, and cognitive impairment with behavioral and psychiatric symptoms [ Smith et al.
A number of genes have been mapped and isolated to the critical region, but except for RAI1, their participation in the pathogenesis of the syndrome remains unclear. Virtually all cases occur de novo, suggesting a low recurrence risk.
SMS is probably under diagnosed due to mild facial abnormalities and the behavioral problems that are not prominent until the affected child is older [ Gropman et al. Variable levels of cognitive impairment, most frequently in the moderate range of intellectual disability, are universal in individuals with Smith-Magenis syndrome.
Speech and language delays are present in most cases, with receptive skills generally better than expressive language skills.
Distractibility is characteristic of the syndrome. Learning abilities are characterized by strength in visual reasoning tasks and weakness in sequential processing counting, mathematical, and multi-step tasks. Short-term memory is poor, but long-term memory is considered a relative strength [ Dykens et al.
The striking neurobehavioral phenotype that characterizes the syndrome emerges over time, beginning between months of age, when head-banging and autistic-like behaviors are seen [ Gropman et al.
Parents generally do not report issues with sleep until after 18 months of age; however, sleep actigraphy data suggests sleep dysfunction as early as 9 months of age [ Duncan et al. With increasing age, psychomotor delays and the emerging neurobehavioral and sleep difficulties often lead to referral and pursuit of diagnostic workup.
Previous studies suggest that age, degree of cognitive delay and levels of sleep disturbance are associated with maladaptive behavior [ Dykens and Smith, ; Finucane et al.
Maladaptive behaviors include hyperactivity, impulsivity, temper tantrums mainly in response to changes in routineand aggression. The latter, could be so severe that in some cases, parents have been reported to social services for suspicion of child abuse [ Smith et al.
Two types of self-hugging are described: These movements appear as an expression of happiness or excitement and are involuntary, with a tic-like quality. Mild to moderate generalized hypotonia impacts early motor development and a fine motor tremor may be observed [ Gropman et al.
Individuals with SMS also have been described to have stereotypies, sensory integration difficulties and social communication problems consistent with select features of autism spectrum disorders ASD.
This study expands our previous work to describe co-morbid autism spectrum disorders ASD in individuals diagnosed with Smith-Magenis Syndrome.
Materials and Methods Participants The study includes 26 individuals 15 females and 11 maleswith a confirmed deletion del 17p Full-scale intelligence quotients IQ for 21of the 26 subjects enrolled in the natural history study of SMS were available for inclusion in the data analysis.
The IQ scores in this population ranged from 40 to 80, with a mean and standard deviation of 56, and 10 respectively.
Instruments Social Responsiveness Scale SRSdeveloped by Constantino and Bruber is a well validated item questionnaire used to evaluate the current behavioral and developmental history for children and adolescents between years of age. Both versions of the SCQ yield a single total score. For the SCQ-Lifetime, a cutoff score of 15 or greater is used as indicator of possible ASD and reason for referral for more comprehensive assessment.
Descriptive statistics were derived and the total scores and subscores obtained from the SRS and the SCQ were analyzed as continuous dependent variables using t-tests.Smith-Magenis Syndrome (SMS) is a rare neurobehavioral disorder characterized by a recognizable pattern of physical, behavioral, and developmental features.
It is caused by particular genetic changes on chromosomal region 17p, which contains the gene RAI1. Smith-Magenis syndrome was first reported in the medical literature in by Ann Smith, a genetic counselor, and colleagues.
In , Smith and Dr. R. Ellen Magenis identified nine patients with the disorder further delineating the syndrome. Monosomy is a form of aneuploidy with the presence of only one chromosome from a pair.
Partial monosomy occurs when only a portion of the chromosome has one copy, while the rest has two copies. Human monosomy. Human conditions due to monosomy. Analysis of the Sensory Pro!le in Children with Smith–Magenis Syndrome Hanna L. Hildenbrand1 &ashio-midori.com2 1Department of Rehabilitation Medicine, National Institutes of Health, Bethesda, Maryland, 2Of!ce of the Clinical Director, Human Genome Research Institute.
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Aug 28, · Smith-Magenis syndrome (SMS) is a developmental disorder that affects many parts of the body. The major features of this condition include mild to moderate intellectual disability, delayed speech and language skills, distinctive facial features, sleep disturbances, and behavioral problems.