Abnormalities of chromosome number can cause spontaneous miscarriage or the birth of a baby with congenital malformations and developmental delay. This is a rapid test of the numbers of selected chromosomes in a blood sample, a sample of the placenta, CVS, amniotic fluid, or fetal blood. This test provides diagnostic and prognostic information. The standard set of tested chromosomes are 13, 18, 21, X, and Y. Other FISH probes can be added on specific requests (e.g. 22q11.2).

In Prenatal Scenario

• chevron_rightPositive maternal serum marker test
• chevron_rightAbnormal ultrasonography (USG)
• chevron_rightAdvanced maternal age
• chevron_rightFamily history of chromosomal abnormality (eg: Downs syndrome)

In Postnatal Scenario

• chevron_rightSuspecting chromosomal abnormality
• chevron_rightHistory of BOH
• chevron_rightBaby with congenital malformations

FISH is a less time-consuming technique in comparison to the conventional method of cytogenetic metaphase karyotype analysis because in the former the detection technique involves processing with either freshwater or paraffin-embedded interphase nuclei without the need of culturing. By using this technique, specific cytogenetic abnormalities, as well as a copy of aberrations numbers, can be enumerated and sketched.

For example, chromosomal microdeletion, amplification, and subsequently, translocation can easily be detected through FISH. The improved diagnostic techniques have made the treatment easier and increased the life expectancy of people. Therefore, FISH is becoming a more vital tool to detect and monitor the specific therapy with regards to the gene abnormalities.