01-10-2006, 03:43 PM
A 16-year-old girl has generalized weakness and nocturnal leg cramps. She is not taking any medications. Laboratory studies show:
Serum
Na+ 135 mEq/L
Cl“ 108 mEq/L
K+ 2.8 mEq/L
HCO3“ 21 mEq/L
Urine pH 7.0
Which of the following is the most likely diagnosis?
A) Adrenal insufficiency
B ) Hyporeninemic hypoaldosteronism
C) Nephrogenic diabetes insipidus
D) Renal tubular acidosis
E) Syndrome of inappropriate ADH (vasopressin)