A handful of mutations associated with various syndromes, such as Apert syndrome [20,21,23,24], Noonan syndrome [22,23,26], MEN2B [21], thanatophoric dysplasia I and II (TDI and TDII) [28], ACH [25], Pfeiffer syndrome [23,28], HCH, Crouzon, MEN2A, and Beare–Stevenson syndromes [23], exhibited larger clusters in testes of older donors. Here, RET is linked to Pfeiffer syndrome.