Snapshot A 27-year-old G1P0 woman present to the labor and delivery floor for labor. She received little prenatal care due to poor insurance. After 2 hours, she successfully delivered vaginally a 7 lbs baby girl. A physical examination of the newborn demonstrates clitoral enlargement and labial fusion. A week later, the infant is brought to the emergency room for inability to feed. She is underweight and dehydrated by appearance with a low blood pressure. (21-hydroxylase deficiency) Introduction Introduction login to view 12 more bullets Overview of Congenital Adrenal Hyperplasia Enzyme Deficiency Presentation Blood Pressure Mineralocorticoids Sex Hormones Cortisol [K+] 17 α-hydroxylase XY: ambiguous genitalia, undescended tests XX: lacks secondary sexual development ↑ ↑ ↓ ↓ ↓ 21- hydroxylase XX: virilization Salt-wasting in infancy Precocious puberty in children ↓ ↓ ↑ ↓ ↑ 11 β-hydroxylase XX: virilization ↑ ↓ Aldosterone↑ 11-deoxycorticosterone (↑ BP) ↑ ↓ ↓ 17α-hydroxylase Deficiency Defect of the CYP17A1 gene, leading to defective CYP17A1 enzyme, which catalyzes both the 17-hydroxylase and the 17,20-lyase reaction Leads to accumulation of cortisol precursor with mineralocorticoid activity login to view 2 more bullets Presentation login to view 6 more bullets Studies login to view 5 more bullets Treatment login to view 4 more bullets Complications login to view 2 more bullets 21-hydroxylase Deficiency Most common form Defects of the CYP21A2 gene leads to defective 21-hydroxylase enzyme, which is responsible for the conversion of 17-hydroxyprogesterone (17OHP) to 11-deoxycortisol Large amounts of 17-hydroxyprogesterone is diverted to the synthesis of androgens and its precursors Presentation login to view 15 more bullets Imaging login to view 2 more bullets Studies login to view 5 more bullets Treatment login to view 4 more bullets Complications login to view 4 more bullets 11β-hydroxylase Deficiency Defect of CYP11B1 gene leads to defective 11β-hydroxylase activity, which is responsible for the conversion 11-doxycorticosterone (DOC) and 11-deoxycortisol to corticosterone and cortisol respectively Accumulation of 11-dexosyteroid precursors leads to the overproduction of mineralocorticoid DOC and androgen precursor dehydroepiandrosterone sulfate (DHEAS) login to view 2 more bullets Presentation login to view 5 more bullets Studies login to view 4 more bullets Treatment login to view 4 more bullets Complications login to view 3 more bullets