Gonadal dysgenesis If a single or combination of these genes are mutated or deleted, downstream signalling is disrupted, leading to malformation of male external genitalia. SRY acts on gene SOX9 which drives Sertoli cell formation and testis differentiation. An absence in SRY causes SOX9 to not be expressed at the appropriate time or concentration, leading to a deficiency in testosterone and Anti-Müllerian hormone production. Inadequate levels of testosterone and Anti-Müllerian hormone disrupts the development of Wolffian ducts and internal genitalia that are key to male reproductive tract development. The lack of the male associated steroid hormones drives Müllerian duct development and perusal
Sexual frustration For males it could be that they have testicles and no penis; a male might be born without a penis (aphallia) or be born with one and have it removed (penis removal or penectomy). Men can still ejaculate via prostate stimulation in that case. For females they might not have a clitoris which causes sexual pleasure; a female might have had her clitoris forcibly severed (female genital mutilation) or voluntarily removed (female circumcusion) as part of a medical procedure. Involuntary celibacy is a form of sexual frustration. Sexual frustration Sexual frustration in humans is frustration caused by a discrepancy between