Heterozygosity assessment of five STR loci located at 5q13 region for preimplantation genetic diagnosis of spinal muscular atrophy.

Preimplantation genetic diagnosis (PGD) has been considered as an alternative to prenatal diagnosis for prevention of genetic disorders while avoiding the subsequent termination of pregnancy. However, the limited amount of template DNA available in a single diploid cell used for PGD leads to number of problems including an increased incidence of detectable contamination; amplification failure and allele drop out. Due to their highly polymorphic and amplifiable characteristics, short tandem repeat (STR) analysis has been proposed as a mean to overcome these limitations.

"Familial" versus "Sporadic" intellectual disability: contribution of common microdeletion and microduplication syndromes.

Background: Interstitial Microdeletion and Microduplication syndromes have been proposed as a significant cause of sporadic intellectual disability (ID) but the role of such aberrations in familial ID has not yet been investigated. As the balanced chromosomal abnormalities commonly lead to the recurrent ID or multiple congenital anomalies, this study was designed to evaluate whether it was justified to investigate such aberrations in familial ID patients. Three hundred and twenty eight patients from 101 unrelated Iranian families with more than two ID patients in the first-degree relatives, have been investigated.

"Familial" versus "sporadic" intellectual disability: contribution of subtelomeric rearrangements.

Background: Cryptic subtelomeric rearrangements have been proposed as a significant cause of sporadic intellectual disability (ID) but the role of such aberrations in familial ID has not yet been studied. As positive family history of ID had been proposed as an important and significant predicting factor of subtelomeric rearrangements, it was assumed that the contribution of subtelomeric aberrations in familial ID would be much more than the sporadic ones. Three hundred and twenty two patients from 102 unrelated families with more than two ID patients in the first degree relatives have been investigated.