For individuals who carry a translocation, inversion, or other chromosome rearrangement, PGD can be used to test embryos for the specific rearrangement. Individuals that carry a balanced chromosomal translocation contain all of their genetic information; however, pieces of some chromosomes have switched places.
Other types of chromosome rearrangements include inversions (where a piece of a chromosome has reversed orientation), deletions (where a piece of a chromosome is missing), duplications (where a piece of a chromosome has duplicated itself) and insertions (where a piece of a chromosome has been inserted into the incorrect location).
Individuals that carry chromosomal translocations are typically healthy; however, they are at increased risk for miscarriage, stillbirth, and/or having a child with birth defects. PGD can reduce the likelihood of having to deal with these particular circumstances by knowing prior to conception that the embryo(s) transferred are balanced for the translocation or are non carriers. This greatly decreases the risk for miscarriage and/or the birth of a child with multiple congenital anomalies.