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Difficulty: MediumPediatric Endocrine Disorders

Match each clinical presentation of a pediatric patient with the most likely underlying endocrine condition.

  • A 2-week-old female infant with ambiguous genitalia, poor feeding, vomiting, hyponatremia, and hyperkalemia.21-hydroxylase deficiency
  • A 3-year-old girl with clitoromegaly, rapid somatic growth, hypertension, and hypokalemia.11β-hydroxylase deficiency
  • A 16-year-old phenotypic female with primary amenorrhea, absent pubic hair, hypertension, and hypokalemia.17α-hydroxylase deficiency
  • A 6-year-old girl with isolated bilateral breast enlargement, normal growth velocity, and bone age equal to chronological age.Premature thelarche

Answer

The first presentation matches 21-hydroxylase deficiency, the second matches 11β-hydroxylase deficiency, the third matches 17α-hydroxylase deficiency, and the fourth matches Premature thelarche.
The matches successfully pair each clinical syndrome with its underlying pathophysiology based on the specific presence or absence of mineralocorticoid effects (blood pressure, potassium levels) and sex steroid effects (virilization, amenorrhea).

Step-by-Step Solution

1
Analyze the first presentation for signs of virilization and electrolyte abnormalities.
The infant has ambiguous genitalia (virilization) and salt-wasting (hyponatremia, hyperkalemia), pointing to a block in both aldosterone and cortisol synthesis with shunting to androgens.
Identifying both androgen excess and mineralocorticoid deficiency isolates 21-hydroxylase deficiency.
2
Analyze the second presentation for virilization and blood pressure status.
The girl has virilization but presents with hypertension and hypokalemia, indicating mineralocorticoid excess.
11β-hydroxylase deficiency blocks cortisol and aldosterone but leads to a buildup of 11-deoxycorticosterone (a weak mineralocorticoid) and shunts precursors to androgens.
3
Analyze the third presentation for sexual development and blood pressure status.
The patient is a phenotypic female with absent secondary sexual characteristics (no androgens/estrogens) and hypertension/hypokalemia (mineralocorticoid excess).
17α-hydroxylase deficiency blocks both the glucocorticoid and sex steroid pathways, shunting all precursors to the mineralocorticoid pathway.
4
Analyze the fourth presentation for signs of true puberty versus benign variants.
The girl has breast development but normal growth velocity and bone age.
The absence of advanced bone age or rapid growth rules out central precocious puberty, confirming benign premature thelarche.

Key Concept

Clinical differentiation of congenital adrenal hyperplasia enzyme deficiencies and benign pubertal variants.
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Topics

Pediatric Endocrine Disorders

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