Combined with previously reported males with MEGF8-associated CRPT2, all males with MEGF8-associated CRPTS have demonstrated cryptorchidism, which is also common but not universally reported in RAB23-associated CRPT1 (MEGF8: 9/9 males; RAB23 14/23 males; Fisher’s exact P = 0.035). This evidence concerns the gene RAB23 and cryptorchidism.