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 for...

Genetic aberrations are commonly seen in human preimplantation embryos. Non-disjunction and premature division of a chromosome are common in both meiosis and mitosis divisions. The expected result for meiotic aneuploidies is full aneuploidy in the later stages whereas mosaicism is the most frequent event in the cleavage and blastocyst stages. The main causes for mosaicism are post-zygotic event...

Key content Fetal placental mosaicism, of which confined mosaicism is a subtype, occurs in 2–3% pregnancies. Confined may lead to false positive result on non-invasive prenatal testing (NIPT) for common aneuploidies. The risk chorionic villus sample (CVS) following NIPT 2, 4, 22 and 59% trisomy 21, 18, 13 45, X respectively. Following the absence significant fetal structural anomaly (FSA), care...

Whole-chromosome copy number alterations, also known as aneuploidy, are associated with adverse consequences in most cells and organisms. However, high frequencies of aneuploidy have been reported to occur naturally in the mammalian liver and brain, fueling speculation that aneuploidy provides a selective advantage in these organs. To explore this paradox, we used single cell sequencing to obta...

Aneuploidy-chromosome instability leading to incorrect chromosome number in dividing cells-can arise from defects in centrosome duplication, bipolar spindle formation, kinetochore-microtubule attachment, chromatid cohesion, mitotic checkpoint monitoring or cytokinesis. As most tumours show some degree of aneuploidy, mechanistic understanding of these pathways has been an intense area of researc...

BACKGROUND Chromosome abnormality (CA) including Sex chromosomes abnormality (SCAs) is one of the most important causes of disordered sexual development and infertility. SCAs formed by numerical or structural alteration in X and Y chromosomes, are the most frequently CA encountered at both prenatal diagnosis and at birth. OBJECTIVE This study describes cytogenetic findings of cases suspected ...

An infertile couple was referred for intracytoplasmic sperm injection (ICSI) because of primary infertility and oligoasthenoteratozoospermia (OAT) in the male. It was observed that although the sperm cells presented with an unusual head size and multiple tails they were able to fertilize the oocytes after ICSI. Subsequent molecular cytogenetic analysis demonstrated de-novo chromosome abnormalit...

 Abstract  Background: Mosaic form of turner syndrome that represented by two or more  cell lines in an affected individual, often has limitation for detection with classical  cytogenetic methods. The present study was carried out to compare the efficiency of  interphase Fluorescence In Situ Hybridisation (FISH) and cytogenetic techniques in  detection of mosaic form of turner syndrome.  Method...

background chromosomal abnormality plays an important role in different types of miscarriages. objectives the present study was designed to investigation chromosomal anomalies in three groups of couples with recurrent abortion (ra), spontaneous abortion (sa) and still birth (sb). patients and methods in this retrospective study, the frequency of chromosomal aberrations was investigated among 26...

Background: Sperm chromatin insufficiencies leading to low sperm count and quality, infertility and transmission of chromosomal microdeletion and aneuploidies to next generations can be due to exposure to environmental pollutions, chemicals and natural or manmade ionizing radiation. In this project which has continued for more than 10 years and is unique in many technical aspects in Iran and in...