Erroneous glucose recordings while using mutant variant of quinoprotein glucose dehydrogenase glucometer in a child with galactosemia
A 2-month-old male child was admitted to our hospital for jaundice and failure to thrive. The child was the first child born of a third degree consanguineous marriage. His birth weight was 3.5 kg. At 1 month of age, the child was noticed to have a yellowish green discoloration of the conjunctiva. The parents reported feeding difficulties and poor weight gain. His current weight was 2.8 kg. He was anemic, icteric and had hepatomegaly. The liver function tests revealed a cholestatic pattern. Admission arterial blood gas was suggestive of compensated metabolic acidosis with a high anion gap. His urine examination revealed ketonuria. Upon admission, random capillary glucose was performed, which revealed a value of 310 mg/dL [].\nSubsequent readings taken every hour for the next 6 h were above 250 mg/dL. Capillary glucose testing was performed using Accu-Check\n® Performa (Roche diagnostics, Mannheim, Germany) glucometer. In view of suspected diabetic ketoacidosis, an endocrinology consultation was sought and hydration and insulin infusion were considered. However, the corresponding random venous plasma glucose was 67 mg/dL (performed using glucose oxidase method) and there was an absence of glucosuria. Hence, it was decided to withhold insulin infusion and potentially fatal hypoglycemia was avoided. In view of a possible cross reaction of high galactose with the glucometer, which employs a MutQ-GDH chemistry further testing was not performed using the same glucometer. A Benedict's test of urine showed the presence of reducing sugars. A quantitative test for galactose-1-phosphate uridyl transferase in whole blood showed a value of 3.85 U/g Hb (normal range 11-41.0 U/g Hb).\nQuantitative test for galactose 1-phosphate in red blood cell was 1.8 mg/dL (normal range 0-1 mg/dL). A liver biopsy revealed macrovesicular steatosis with bile duct proliferation and a fibrosis score of 4/6 [].\nThe child was started on a galactose free formula. He showed steady improvement with resolution of jaundice and weighed 4.0 kg on repeat examination 1 month later.