A one-year-old child who was born with a birth weight of 3 kg at 38 week of gestation, was 7 kg at the end of one year. Investigations revealed:
HCO3 – 10
Serum sodium – 138
Serum potassium – 5
Serum chloride – 120
Urinary pH – 5.5
Urine also showed generalised glycosuria, phosphaturia, and aminoaciduria.
a) What is the cause of acidosis in this child?
b) What is the most common cause?