7 month old male baby refered for ricket. 2 earlier siblings died before attaining 3 years age. Pt growth normal, vital normal, irritated, no sign or symptom of any infection Xray of joints revealed ricket changes.Investigation: Urine RE Normal. Blood RE Normal.S Creat 0.2mg, sugar 98. Blood Ph 7.40, PCO2-26.1,HCO3-16.4,Sodium-142, Potassium 3.3,Chloride- 105, Hb-8.2.
Urine PH-7.5, sodium 17meq, Potassium 38meq, Chloride 25meq. Xray abdomen- no calcification in KUB area. In view of low serum bicarb,high urine PH and high urine anion gap (30), diagnosis of renal tubular acidosis is most likely. My query is regarding the high anion gap in this case (20) which is unlikely in RTA.