Cytogenetics is the study of normal and abnormal chromosomes. This includes examination of chromosome structure and phenotype, and seeking out the causes of chromosomal abnormalities. Manifestations of chromosomal abnormalities are diverse and numerous, including early embryonic death, minor to major congenital defects, development of cancer, and infertility or sterility.
The Cytogenetics tests include Constitutional Karyotyping (Peripheral Blood / Cord Blood / Foetal Blood), Prenatal Karyotyping on Amniotic Fluid, Tumor Karyotyping on Bone Marrow Aspirate and Constitutional FISH (Microdeletion Syndrome). Rapid molecular analysis of common genetic disorders complements our Cytogenetics services.
Glossary
Euploidy is the condition of having a normal number of structurally normal chromosomes.
Aneuploidy is the condition of having less than or more than the normal diploid number of chromosomes, and is the most frequently observed type of cytogenetic abnormality.
The two most commonly observed forms of aneuploidy are monosomy and trisomy:
• Monosomy is lack of one of a pair of chromosomes. A common monosomy seen in many species is X chromosome monosomy, also known as Turner's syndrome. Monosomy is most commonly lethal during prenatal development.
• Trisomy is having three chromosomes of a particular type. A commonautosomal trisomy in humans is Down syndrome, or trisomy 21, in which a person has three instead of the normal two chromosome 21s.
A chromosome deletion occurs when the chromosome breaks and a piece is lost. This involves loss of genetic information.
A chromosome inversion is a break or breaks occur and that fragment of chromosome is inverted and rejoined rather than being lost. Inversions are thus rearrangements.
Translocations are chromosomal abnormalities which occur when chromosomes break and the fragments rejoin to other chromosomes.
