Background and Objectives: Primary amenorrhea is not a disease but a symptom that may result from several quite different causes[NN1] . Common hormonal cause of primary amenorrhea includes constitutional delay, hypothalamic –pituitary dysfunction, chronic systemic disease and absent ovarian function. The aim of this study was to estimate the incidence of the chromosomal abnormality referred ...

Background: Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses before 20 weeks of gestation as an important clinical problem, with an incidence of 1-3% among couples wishing to have children. There are several factors in the etiology of recurrent miscarriage. One of the main genetic causes which involve in the pathogenesis of RM is balanced chromosomal rearrangeme...

chromosomal abnormalities are major causes of infertility, miscarriage and birth of handicapped progeny. in human live births, the prevalence of a chromosome aberration is ?0.5% and, of these, 0.1–0.3% correspond to structural chromosome rearrangements such as translocations, inversions, insertions and deletions .our proband is an infant who had died 4 hours after birth due to a variety of abno...

amniocentesis is a known and accessible method for prenatal diagnosis. it is performed after the 15th week of gestation. in this method, about 20 ml of the amniotic fluid is aspirated and evaluated for biochemical tests, culture of amniocytes for karyotype, dna analysis and linkage tests based on indication. the objective of this study was to determine the indications, results and complications...

Background: Chromosomal alterations play an important role in carcinogenesis. Enhanced chromosomal radiosensitivity is shown for many cancer predisposition conditions including breast cancer. In this study chromosomal radiosensitivity and the frequency of background sister chromnatid exchanges (SCE) in lymphocytes of normal individuals and breast cancer patients was compared. Materials...

Background: The advances in cytogenetic techniques during the last few years have permitted not only the study of large populations of wild and domestic animals, but also the detection of chromosome anomalies in embryos. Chromosomal abnormalities are the most common cause of embryonic and fetal mortality in mammals. Most reports of chromosome anomalies in parthenogenetic embryos describe numeri...

re chromosomes distributed randomly within the cell nucleus during interphase, or do they preferentially cluster into specific groups? On page 237, Cornforth et al. address this question, which has been debated vigorously for nearly a century, and conclude that the distribution of chromosomes within the nucleus of human cells is mostly, but not entirely, random. The work provides the most compr...