PGS test for chromosomal abnormalities only. Preimplantation genetic diagnosis or PGD tests for single gene mutations associated with genetically inherited disease, e.g. cystic fibrosis, sickle cell anemia, muscular dystrophy, Huntington's Disease, Fragile X syndrome and many more.

Now such diagnostics are important before planning a pregnancy. You can view details here. Now there are companies that can help you get it right.