ELECTROLYTE QUIZ

The Question

A 24-year-old male was evaluated for a 4 year history of hypertension and hyperkalemia. His father and one of his two siblings had a similar condition. Exam was remarkable only for BP 166/104 mmHg. 

Laboratory Studies

Serum sodium 144 mEq/L

Serum potassium 6.9 mEq/L

Serum chloride 115 mEq/L

Serum bicarbonate 20 mEq/L

Serum creatinine 0.7 mg/dL

Plasma renin activity 0.1 ng/mL/hr (Normal range 1-6)

Plasma aldosterone 4.8 ng/dL (Normal range 5-20)

Serum cortisol  27 mcg/dL (morning)

24 hr urine potassium 15 mEq

24 hr urine cortisol  320 nmol  (Normal range 97-441)

Which of the following is the most likely cause of this patient’s abnormalities:

A. Gordon syndrome

B. Pseudohypoaldosteronism, Type I

C. Addison disease

D. Conn syndrome

E. Syndrome of apparent mineralocorticoid excess 

(Case provided by Dr. Alan Yu, UKMC)