A 37-year-old Indian male, software professional presented with  C/o  chest pain, belching, indigestion, fatigue, lethargy, vague body pains, H/o gastritis,  grade 1 hemorrhoids,  renal calculus of 4mm Endoscopy and colonoscopy normal Blood Investigations: Serum calcium 10.8  Serum phosphorus 3.2 PTH  (parathormone) levels -50 Urea 14mg/dl  Serum creatinine 0.9 Uric acid 8.4 SERUM electrolytes Normal  Blood sugar normal  Complete blood counts normal Urine analysis normal. What could be the probable diagnosis?