Figure 1 Male genitalia in a four-month-old infant showing hyperpigmentation.
Investigations showed deranged electrolytes with serum sodium: 119 mmol/L, serum potassium: 1.7 mmol/L, and serum creatinine: 61.89 µmol/L. Random blood sugar was 0.89 mmol/L. The hyponatremia and hypokalemia were assumed to be caused by dehydration owing to diarrhea and vomiting from the past three days. His initial blood gas analysis showed: pH- 7.54 (7.35-7.45), pCO2 3.99 kPa (4.27-6), HCO3 27.3 mmol/L (22-28) suggestive of respiratory alkalosis. Normal levels of Magnesium (0.74 mmol/L) and ionized Calcium (1.11 mmol/L) successfully ruled out the possibility for Bartter and Gitelman syndrome. The lab results are outlined in Table 1. The stool for reducing substances was found to be negative. C-peptide was done to rule out insulinoma which was 0.15 ng/ml. Liquid chromatography- tandem mass spectrometry (LC-MS/MS) was done to rule out any inborn metabolic errors, which reported to have no obvious organic aciduria.