Question

A karyotype that uses FISH that shows two chromosomes, each with two colors, but in the opposite patterns, most likely indicates a

A. Robertsonian translocation.
B. pericentric inversion.
C. paracentric inverson.
D. reciprocal translocation.

Answer 1

A karyotype using FISH showing two chromosomes with two colors in opposite patterns likely indicates a reciprocal translocation, where segments of two different chromosomes are swapped.

Step-by-step explanation:

A karyotype that uses Fluorescence In Situ Hybridization (FISH) displaying two chromosomes, each with two colors in opposite patterns, is indicative of a reciprocal translocation. In a reciprocal translocation, segments from two different chromosomes are swapped, causing the chromosomes to display segments of genes that are normally found on the other chromosome, which can be visualized as different colors using FISH.

This contrasts with Robertsonian translocation where the long arms of two acrocentric chromosomes fuse at the centromere and form one chromosome, with a pericentric inversion involving a chromosome segment that includes the centromere being flipped in orientation, and a paracentric inversion where a segment outside of the centromere is reversed.