PGT-A (aneuploidy) This test determines whether the correct number of chromosomes are present in the embryo; PGT-M (monogenic) This test screens for single gene disorders such as cystic fibrosis, BRCA1 & 2, or Huntington Disease; PGT-SR (structural rearrangements) Screens for chromosome rearrangements like chromosome inversions and translocations. All three types of PGT require IVF, or in vitro fertilization.