MSH6 and Lynch syndrome: PGT-M offers several advantages in the context of Lynch syndrome (26, 32, 33): (1) high specificity, enabling accurate detection of known pathogenic variants such as MSH6 c.3261dupC for targeted embryo selection (34); (2) effective genetic prevention by selecting embryos free of the mutation, thereby halting vertical transmission; (3) psychological benefits for future offspring by eliminating the need for lifelong cancer surveillance and associated anxiety; and (4) ethical advantages by ensuring reproductive safety without relying on prenatal diagnosis followed by medical termination.