OBJECTIVE: To estimate the frequency of subtelomeric rearrangements in @entity1 with sporadic and @entity1032 (IMR). METHODS: A total of 18 IMR @entity1 were taken for the study. Selection criteria included no known syndromes or @entity2008 and known causes of IMR. All @entity1 signed an informed consent to participate. Chromosome analysis was carried out on all @entity1 to rule out gross chromosome abnormalities. Lymphocyte cultures were initiated and harvested using standard protocols. For fluorescence in situ hybridization (FISH), Chromoprobe Multiprobe-T system was used. This system consists of 24 embossed areas with each area having one reversibly bound subtelomere probe for a specific chromosome. The subtelomere probes were differentially labeled with green fluorescence for short arm and orange for the long arm. Hybridization, washing and staining are done using standard protocols. A minimum of 5 metaphases were analyzed per chromosome per @entity1 . RESULTS: A total of 2 subtelomeric rearrangements were detected (11.1%). Case 1 involved a 17-year-old with severe @entity90 , profound @entity2319 and @entity154 with reciprocal translocation t(3;7)(q26.2; p15.1). The second case involved a 4.6-year-old with mild @entity245 and a terminal deletion of the long arm of chromosome 2, del(2) (q37.3). The frequency of abnormalities detected in our study is in agreement with published reports. CONCLUSION: Subtelomeric screening with FISH is a useful tool for investigation of IMR, however, it is not cost effective in all cases. Conventional chromosome analysis coupled with targeted FISH testing might be the optimal strategy for investigation of IMR.

Subtelomeric rearrangements in idiopathic XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity154 :: ('MESH:D000013', 'Disease') :: ['dysmorphic features'] @entity1032 :: ('MESH:D008607', 'Disease') :: ['non-syndromic idiopathic mental retardation'] @entity90 :: ('MESH:C564570', 'Disease') :: ['MR'] @entity245 :: ('MESH:D002658', 'Disease') :: ['developmental delay'] @entity2319 :: ('MESH:D003638', 'Disease') :: ['deafness'] @entity2008 :: ('MESH:D002869', 'Disease') :: ['chromosomes abnormalities']
@entity1032 :: (MESH:D008607,Disease) :: ['mental retardation']
