Pre-Implantation Genetic Testing for Monogenic Diseases (PGT-M) or Chromosomal Structural Rearrangements (PGT-SR) (formerly known as single-gene or chromosomal PGD) detect specific genetic and chromosomal alterations in embryos. It is suitable for couples where one or both partners are known carriers of serious genetic conditions or chromosomal structural rearrangements (known as a translocation) who want to prevent their offspring from inheriting a condition or chromosomal imbalance.