Thalassemia is a hereditary
anemia resulting from defect in
hemoglobin production.
Beta thalassemia is due to impaired production of
beta globin chains, leading to a relative excess of
alpha globin chains. The term
beta thalassemia minor is used to describe heterozygotes, who carry one normal
beta globin allele and one beta thalassemic allele. The vast majority of these patients are asymptomatic. However, a variety of renal tubular abnormalities including
hypercalciuria, hypo-magnesemia with renal
magnesium wasting, decreased tubular absorption of
phosphorus, hypo-uricemia with renal
uric acid wasting,
renal glycosuria and tubular
proteinuria have been described even in patients with
beta thalassemia minor. We here in report a 24-year old female patient who was found to have
thalassemia minor and
nephrocalcinosis with evidence of renal tubular dysfunction. Investigations revealed normal renal function,
hypercalciuria, reduced tubular reabsorption of
phosphorus, hypomagnesemia and renal
magnesium wasting. Screening for aminoaciduria was found to be negative. An
acid loading test revealed normal urinary acidification. Ultrasonogram of the abdomen revealed
nephrocalcinosis and
splenomegaly. Detailed work up for
anemia showed normal white cell and platelet count while peripheral smear showed microcytic
hypochromic anemia with few target cells.
Hemoglobin electrophoresis revealed
hemoglobin A of 92%,
hemoglobin A2 of 6.2% and hemo-
globin F of 1.8% consistent with
beta thalassemia minor. Her parental screening was normal. A diagnosis of
beta thalassemia minor with renal tubular dysfunction was made and the patient was started on
thiazide diuretics to reduce
hypercalciuria and advised regular follow-up.