Which PGT test is used to screen for aneuploidy?

• A. PGT-M
• B. PGT-SR
• C. PGT-D
• D. PGT-A

Answer: (D)

Focuses on embryo chromosome number. Preimplantation genetic testing has different purposes: one type is specifically designed to assess the total chromosome complement of an embryo to detect aneuploidy (an abnormal number of chromosomes). This is the aim of PGT-A. By screening for aneuploidy, it helps identify embryos with chromosomal imbalances that can lead to implantation failure, miscarriage, or congenital issues.

For completeness, the other types address different genetic targets. PGT-M looks for specific single-gene mutations causing inherited disorders. PGT-SR checks for chromosomal structural rearrangements, such as translocations or inversions. PGT-D is used for conditions not defined by a single gene or a known chromosomal rearrangement, often broader or less clearly characterized genetic problems.

So, when the goal is to screen for the number of chromosomes, the appropriate test is PGT-A.