This test is used to analyze the blood sample of an individual for identifying common chromosome disorders using FISH (Fluorescence in-situ Hybridisation). This test is performed to diagnose a chromosomal abnormality or genetic disorder. This test is accurate and has a low rate of false positive results.
What is FISH test?
Fluorescence In-Situ Hybridisation or FISH, in short, is a procedure used to picture the chromosomes (genetic material) of an individual. This test is useful in identifying various genetic diseases which may have been caused due to duplication, deletion, or misarrangement in chromosomes.
What are chromosomes?
Chromosomes contain the information (genes) regarding the growth and development of an organism. The chromosomes are the condensed form of DNA (Deoxyribonucleic acid) of an organism. Humans contain 46 chromosomes which are arranged in 23 pairs. Reproductive cells like sperm and egg in an individual contain 23 chromosomes which passed from the parent to the child.
The change in the number or arrangement in the chromosomes in an individual leads to the occurrence of various genetic diseases or disorders. Chromosome abnormalities can occur as duplication(extra chromosome) which can be called as trisomy or tetrasomy like Edward’s syndrome (condition in which the baby suffers from severe developmental delays due to an extra chromosome 18), Patau syndrome (a condition that cause intellectual disability and physical abnormalities due to the presence of an extra chromosome 13), Down’s syndrome (the genetic disorder which causes developmental and intellectual delays due to the presence of chromosome 21), other chromosomal abnormalities include presence of an extra X or Y which play a role in the determination of the sex of an individual, deletion (absence of a part or a fragment of a chromosome) and translocations( misarrangement of certain genes).
Why is this test recommended?
The chromosome analysis is recommended if a doctor suspects that an individual might have a genetic disease or defect which might have been caused due to chromosomal abnormalities, If you have a family history or high risk of inherited disease or chromosomal abnormalities, you may also be advised to perform this test.
Inform your doctor if you are on any medications, have any allergies or underlying medical conditions before your Chromosome 18/X/Y Fish Blood. Your doctor will give specific instructions depending on your condition on how to prepare for Chromosome 18/X/Y Fish Blood.
No specific preparation is necessary for this test.
The positive result or presence of an abnormal number of (aneuploidy) of chromosomes X/Y/13/18/21 may indicate chromosome disorders.
Presence of an extra chromosome 13 may indicate Patau syndrome, an extra chromosome 18 may indicate Edward’s syndrome and an extra chromosome 21 may indicate Down syndrome.
The negative result or normal pattern of chromosomes may indicate that the likelihood of having any chromosome disorders is less.
Based on the test results, your doctor may advise you appropriate medical treatments or further diagnostic tests