(B) Female pseudohermaphroditism[?]Congenital Adrenal Hyperplasia (CAH) is the most common cause of female pseudohermaphroditism & virilization, & decreased cortisol synthesis owing to reduction or loss of 21-hydroxylase enzyme function is the most common biochemical cause of CAH.ABERRANT SEXUAL DIFFERENTIATION DEVELOPMENTAL DISORDERSFemale PseudohermaphroditismMale Pseudohermaphroditism*. Congenital virilising adrenal hyperplasia of fetus*. Maternal androgen excess*. Virilizing ovarian tumor*. Iatrogenic: Treatment with androgens or certain synthetic progestational drugs*. Androgen resistance*. Defective testicular development*. Congenital 17-hydroxylase deficiencyDisorders of Embryonic Sexual Development:Hermaphroditism occurs when individuals have both ovary & testis tissue.Pseudohermaphrodites have either testes or ovaries but have accessory organs & external genitalia that are incompletely developed or inappropriate.Most common cause of female pseudohermaphroditism is congenital adrenal hyperplasia.In males, one cause is testicular feminizing syndrome in which testes are normal but there are no receptors for Testosterone.-Individual develops very female appearance but is infertile.Causes of Female Pseudohermaphroditism:Congenital Adrenal Hyperplasia (CAH):It is caused by a defect in an enzyme (21-hydroxylase) in the steroid hormone synthesis pathway in the adrenal gland. It is the most common cause of ambiguous genitalia in newborns.Causes females to be masculinized due to a deficiency of the enzyme 21- hydroxylase.It is present in about one in 15,000 newborns. It is inherited by an autosomal recessive gene.Overproduction of male hormones before birth:It is often due to adrenal gland abnormality (as described in CAH above).High levels of male hormones may also enter the placenta via the mother (when receives progesterone to prevent a miscarriage or has a hormone-producing tumor).The common cause: Congenital Adrenal Hyperplasia (CAH):95% of CAH:Hypocortisolism; Enzyme 21-hydroxylase deficiency.Increased 17-hydroxy progesterone or 17-OHP. Manifest as virilization (Clitoromegaly, acne etc.,)Cortisol substitution - less masculine & potentially fertile. May cause Addison's Crisis.Newborn female CAH - presence of ambiguous genitalia.Newborn male CAH - similar symptoms with Hypertrophic Pyloric Stenosis (HPS), to differentiate it:-CAH: Hyperkalemia, metabolic acidosis; HPS: Hypokalemia, metabolic alkalosisOther Options[?]True hermaphroditism:Glands of both the sexes must be present in the same individual (cases are very rare).Accessory sex gland is atrophic and shows no evidence of functional activity.Sex gland consists partly of ovarian & partly of testicular tissue.[?]Pseudohermaphroditism:Sex glands are of one sex while the external genitalia are of the opposite sex.[?]Female pseudohermaphroditism ovaries may descend within the inguinal canal to lie in the labia majora, and if the clitoris is hypertrophied, it may at first glance resemble the penis, and the fused labioscrotal folds resemble a rudimentary scrotum.[?]Male pseudohermaphroditism type, the testis fails to descend into the scrotum, the penis is ill developed, and as a result of extreme hypospadias, the external genitalia resemble those of the female.