Various studies from India have shown association between glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in erythrocytes and age-related cataract(1,2). However, its association with childhood or congenital cataract has not been well studied. An 8-year-old boy presented to us with history of bilateral cataract developing at age of 2 years, which was operated at 3.5 years; and pallor requiring 3 blood transfusions at ages 3.5, 4.5 and 8 years. He had received multiple antibiotics including co-trimoxazole for various pharyngeal infections. His mental development was normal, and there was not history of seizures. Family history was negative for early-onset cataract or hemato-logical disorders. On physical examination, patient had bilateral aphakia; mild icterus and pallor. There was no dysmorphism, signifi-cant lymphadenopathy or hepatospleno-megaly.

Laboratory investigations revealed hemoglobin 8.4 g/dL, WBC count 6000/mm3, platelets 386,000/mm3, MCV 101.6 fl, MCH 30.4 pg, MCHC 30 g/dL, red blood cell (RBC) count 2.76 million/mm3 and absolute reticulocyte count 11%. Peripheral smear showed macrocytic erythrocytes with polychromasia. Total bilirubin was 3 mg/dL; direct bilirubin 0.7 mg/dL; serum creatinine 0.6 mg/dL; liver enzymes normal; hemoglobin electrophoresis normal; direct Coombs’ test negative; and bone marrow examination revealed erythroid hyperplasia. Methemo-globin reduction test showed defi-ciency of G6PD enzyme in erythrocytes. On quantitative analysis, G6PD was 93.7 mU/109 erythrocytes (normal: 118-144 mU/109 erythrocytes). Screening for galactosemia in view of early-onset bilateral cataracts was negative with absence of reducing substances in urine.

The patient had congenital nonspherocytic hemolytic anemia due to G-6-PD deficiency with episodic drops in hemoglobin most probably due to cotrimoxazole exposure. G6PD deficiency results in reduced glutathione activity in the lens, making the lens more prone to oxidative damage and resultant aggregation of lens proteins. The development of bilateral cataract at the age of 2 years in a develop-mentally normal child may have been due to the oxidative stress in the lens from G-6-PD deficiency.

There have been three previous reports of early-onset childhood cataract and G-6-PD deficiency(3-5). It, however, remains unclear as to why certain G-6-PD variants predispose to cataract formation. In view of the epidemio-logical studies suggesting the association of G-6-PD deficiency and role of oxidative stress in causation of adult human cataract, and some sporadic reports of childhood cataract with G-6-PD deficiency without any other obvious cause, it is reasonable to consider excluding G-6-PD deficiency in children with cataract.

Sameer Bakhshi,
Madhulika Kabra,
Department of Pediatrics,
All India Institute of Medical Sciences,
New Delhi 110 029,
India.

1. Mohan M, Sperfuto RD, Angra SK, Milton RC, Mathur RL, Undrwood BA et al. India-US case control study of age-related cataracts. India-US Case-Control Study Group. Arch Ophthalmol 1989; 107: 670-676.

2. Bhatia RP, Patel R, Dubey B. Senile cataract and glucose-6-phosphate dehydrogenase deficiency in Indians. Trop Geogr Med 1990; 42: 349-351.

3. Harley JD, Agar NS, Gruca MA, McDermid ME, Kirk RL. Letter: Cataracts with a glucose 6 phosphate dehydrogenase variant. BMJ 1975; 2: 86.

4. Westring DW, Pisciotta AV. Anemia, cataracts and seizures in patient with glucose 6 phosphate dehydrogenase deficiency. Arch Int Med 1966; 188: 385.

5. Helge H, Borner K. Congenital nonspherocytic hemolytic anemia, cataract and glucose 6 phosphate dehydrogenase deficiency. Dtsch Med Wochenschr 1966; 91: 1584-1590.