At a Tertiary Genetic Centre, children with mental retardation (MR) (also referred as intellectual disability) and associated developmental disabilities were investigated for genetic diagnosis which is important in prevention and genetic counseling while offering the risk of recurrence to the family. A prospective and retrospective cytogenetic study was conducted on 1760 MR cases for chromosoma...

Recurrent spontaneous abortions (RSAs) occur in approximately 15 to 20% of all clinically recognizable pregnancies. Structural chromosome abnormalities result in increased risk of pregnancy loss. Parental chromosomal abnormalities are an important genetic cause of RSAs. Some cytogenetic investigations have been performed in various countries and regions to determine the pattern of chromosomal a...

background : turner syndrome (ts) is a sporadic disorder caused by the absence of all or some parts one x-chromosome with major developmental consequences such as short stature and ovarian failure etc. the minor manifestations of ts are cubitus valgus, micrognatism, high-arched palate, short and/or webbed neck, hypothyroidism, etc. different karyotype abnormalities may lead to different clinica...

Ring chromosomes are rare chromosomal disorders that usually appear to occur de novo. A ring chromosome forms when due to deletion both ends of chromosome fuse with each other. Depending on the amount of chromosomal deletion, the clinical manifestations may be different. So, ring 18 syndrome is characterized by severe mental growth retardation as well as microcephaly, brain and ocular malformat...

Direct testing of the outcome of human female meiosis demonstrated that up over a half of oocytes from IVF patients of advanced reproductive age are aneuploid, originating comparably from meiosis I and meiosis II errors, with potential probability of aneuploidy rescue in an almost half of oocytes with sequential first and second meiotic errors. One fifth of abnormalities originating from meiosi...

OBJECTIVE About 15% of clinically recognized pregnancies result in spontaneous abortion in the first trimester and the vast majority of these are the result of chromosome abnormalities. Studies of chromosomal constitutions of first trimester spontaneous abortions have revealed that at least 50% of the abortions have an abnormal karyotype. In this study we aimed to report the single centre exper...

Background: The present study has been carried out to investigate the effects of preovulatory stage gamma-irradiation of female mice in the absence or presence of vitamin E on numerical chromosome abnormalities in 8-cell embryos after mating with non-irradiated males. Materials and Methods: The 8-11 weeks adult female NMRI mice were whole body irradiated at preovulatory stage (post PMSG inject...