Ans. c. Renal glomerular rickets (Ref: Nelson 19/e p202)A child has deficient bone mineralization with low serum calcium, high serum phosphorus, with decreased urinary excretion of calcium and phosphorus and elevated levels of alkaline phosphatase. The most likely diagnosis is renal glomerular rickets."With chronic renal failure, there is decreased activity of 1a-hydroxylase in the kidney, leading to diminished production of 1,25-D. In chronic renal failure, unlike the other causes of vitamin D deficiency, patients have hyyperphosphatemia as a result of decreased renal excretion. Along with inadequate calcium absorption and secondary hyperparathyroidism, the rickets may be worsened by the metabolic acidosis of chronic renal failure. In addition, failure to thrive and growth retardation may be accentuated because of the direct effect of chronic renal failure on the growth hormone axis."- Nelson 19/e p202Laboratory findings in disorders causing ricketsDisorderSerum CaSerum PiSerum PTH25-OH D1,25-(OH)2 DSerum Alk PO4 aseUrine CaUrine PiVitamin D deficiency (nutritional)N, |||||, N, ||||Vitamin D dependent rickets, Type 1N, |||N||||Vitamin D dependent rickets, Type 2N, |||N|||||Chronic renal failureN, |||N||N, ||Dietary Pi deficiencyN|N, |N||||X-linkedhypophosphatemic ricketsN|NNRelatively ||||Autosomal dominant hypophosphatemic ricketsN|N,NRelatively ||||Hereditaryhypophosphatemic rickets with hypercalciuriaN|N,-NRelatively ||||Tumour-induced ricketsN|NNRelatively ||||Fanconi syndromeN|NNRelatively | or ||| or ||Dietary Ca deficiencyN, |||N||||