Preconception carrier screening (CS) is a type of genetic testing performed on couples or individuals who are considering parenthood but are not yet pregnant. The primary purpose of CS is to assess the risk of an individual or a couple of passing genetic disorders to their offspring.1 Over 7000 diseases are expected to follow Mendelian inheritance, of which 40%–50% are estimated to follow recessive inheritance.2, 3 Different from genes with dominant inheritance where a single copy of the mutated gene results in the manifestation of the condition, disorders deriving from aberrant genes with recessive inheritance can manifest only when both copies of the gene are abnormal (whether in homozygosis or compound heterozygosis) or when they are located on the X chromosome of a male individual (X-linked, XL).
CS can be particularly valuable when there is no known family history of a genetic disorder, as carriers are often unaware of their status due to the lack of symptoms. By identifying carrier status before pregnancy, CS informs couples about their reproductive risk, thus increasing their genetic awareness and allowing them to make an informed decision about reproductive strategies and family planning, including natural conception with prenatal diagnosis, the use of assisted reproductive technologies (ART) with preimplantation genetic for monogenic disorders (PGT-M), the use of donor gametes, adoption, or remain childless.
