Mental retardation disorders به نام خدا Mental retardation disorders دکتر اريانه صدرنبوي متخصص ژنتيک انساني

Mental retardation disorders Mental retardation (MR) is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors. It has historically been defined as an Intelligence Quotient score under 70.

Mental retardation IQ –MR Learning Disability 70-85 Milder MR 50-70 Middle MR 35-50 Grave MR <35

Mental retardation 1.)Syndromic mental retardation is intellectual deficits associated with other medical and behavioral signs and symptoms . 2.) Non-syndromic mental retardation refers to intellectual deficits that appear without other abnormalities

Idiopathic mental retardation and Telomere Deletions, other micro deletions Autosomal gens and idiopathic MR X chromosomal non syndromic mental Retardations

Idiopathic mental retardation and Telomere Deletions, other micro deletions

Telomere Analysis and mental retardation IQ –MR Learning Disability 70-85 Milder MR 50-70 Middle MR 35-50 Grave MR <35

1.) familial mental retardation 2.) prenatal growth retardation 3.) postnatal growth retardation 4.) facial signs of dysmorphism 5.) non facial dysmorphism and organic malformations. J Med Genet. 2001 Mar;38(3):145-50. Clinical studies on submicroscopic subtelomeric rearrangements: a checklist. de Vries BB, White SM, Knight SJ, Regan R, Homfray T, Young ID, Super M, McKeown C, Splitt M, Quarrell OW, Trainer AH, Niermeijer MF, Malcolm S, Flint J, Hurst JA, Winter RM. Clinical and Molecular Genetics Unit, Institute of Child Health and Great Ormond Street Hospital, London, UK. Comment in: J Med Genet. 2002 Oct;39(10):E60.

Ish subtel(41x2)

gen3240

46,XY.ish del(8) (p23.3) (D8S2333-)

Phelan-McDermid Syndrome 22q13 Deletion Syndrome (spoken as twenty two q one three), also known as Phelan-McDermid Syndrome, is a genetic disorder caused by a microdeletion on chromosome 22. The deletion occurs at the terminal end of the chromosome at the location designated q13.3. This microdeletion is rarely uncovered by typical genetic screening, therefore a fluorescence in situ hybridization, or FISH, test is recommended to confirm the diagnosis. Recent work indicates Phelan-McDermid Syndrome may also be caused by errors in a single gene (SHANK3/PROSAP2) in the q13.3 region. Errors on the same gene have been associated with Autism Spectrum Disorder (ASD). This genetic disorder is characterized by general hypotonia, absent to delayed speech, and global developmental delays. There are approximately 600 reported cases of Phelan-McDermid Syndrome worldwide. Physical Absent to severely delayed speech: 99% Hypotonia (poor muscle tone): 97% Normal to accelerated growth: 95% Increased tolerance to pain: 86% Thin, flaky toenails: 78% Large, fleshy hands: 68% Prominent, poorly formed ears: 65% Pointed chin: 62% Dolichocephaly (elongated head): 57% Ptosis (eyelid) (droopy eyelids): 57% Poor thermoregulation: 51% Behavioral Chewing on non food items (clothing, bedding, toys):70% Teeth grinding: (percent undetermined) Autistic behaviors: (percent undetermined) Tongue thrusting: (percent undetermined) Hair pulling: (percent undetermined) Aversion to clothes: (percent undetermined

Phelan-McDermid Syndrome

Autosomal gens and idiopathic MR

Rubinstein-Taybi syndrome Mutations in the CREBBP gene Some cases of severe Rubinstein-Taybi syndrome have resulted from a deletion of genetic material from the short (p) arm of chromosome 16. Several genes, including the CREBBP gene, are missing as a result of this deletion. 1 in 100,000 to 125,000 newborns . Additional features of the disorder can include eye abnormalities, heart and kidney defects, dental problems, and obesity. These signs and symptoms vary among affected individuals. People with this condition have an increased risk of developing noncancerous and cancerous tumors, including certain kinds of brain tumors. Cancer of blood-forming tissue (leukemia) also occurs more frequently in people with Rubinstein-Taybi syndrome. Rarely, Rubinstein-Taybi syndrome can involve serious complications such as a failure to gain weight and grow at the expected rate (failure to thrive) and life-threatening infections. Infants born with this severe form of the disorder usually survive only into early childhood.

Rubinstein-Taybi syndrome

Miller Dieker Syndrome del17 p13.3

Miller Dieker Syndrome

Miller Dieker Syndrome

3 p Syndrome

3 p Syndrome Clinical features: developmental delay; growth retardation; dysmorphic features

Non-syndromic mental retardation X-Linked Mental retardation Male 1.2/1.8 x more MR 5 % of all MR is XLMR Prevalence of 1. 600

X-Linked Mental retardation MRX families More than 50 genes found on the human X chromosome have been reported to cause MR with another 150 loci being associated with linked syndromes, non syndrome families and unlinked syndromes

X-Linked Mental retardation FRAXE, OPHN1, IL1RAPL1, TM4SF2, ARHGEF6,GD11, PAK3,RPS6KA3

‍CGH

NXG and MR

خسته نباشيد.