Late childhood presentation with hypokalemic
metabolic alkalosis and hypomagnesemia. Either asymptomatic or occasional
mild episodes of muscle weakness. Symptoms are precipitated by nonspecific
illness and may consist of tetany. Patients are neither polyuric nor
polydipsic, but they have hypocalciuria, renal magnesium wasting, and
absence of nephrocalcinosis. Chronic dermatitis, skeletal problems with
growth retardation (as a consequence of rickets), and chondrocalcinosis;
rarely rhabdomyolysis (secondary to severe hypokalemia) can be observed in
some patients. Long-term prognosis is rather good, especially when potassium
losses are corrected. Treatmentwith oral magnesium corrects the
magnesium deficit but not themetabolic alkalosis. The relationship of
these skeletal abnormalities to magnesium wasting and hypomagnesemia is
not clear.