21-Hydroxylase Deficiency (21-OHD): Pathogenesis and Clinical Findings

Autosomal recessive mutation in CYP21A2 coding for the enzyme 21-OHase causes varying degrees of 21-OHD in the adrenal glands

 • Salt wasting crisis & hyperkalemia do not occur in utero as the placenta maintains appropriate ion concentrations.

 • This is also known as "congenital adrenal hyperplasia". Females may be labeled as males at birth due to an enlarged clitoris. Severity depends on the amount of enzyme deficiency. Severe deficiencies present in infants with "salt wasting crisis" & virilization. Milder forms present with lesser virilization that may only become apparent at or before puberty.



Signs/Symptoms/Complications:

 • Hyperkalemia, Hypoglycemia

 • Early: decr feeding, weight loss, vomiting

 • Late (shock): cold & mottled skin. non-arousable, decr urine output

 • Hirsutism & acne

 • Infertility

 • Precocious puberty

 • Darkened scrotum & enlarged penis months after birth

 • Psychosexual & gender identity difficulties

 • Enlarged clitoris may look like a penis at birth

 • Labia major & minor fuse to look like a scrotum



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