At the first visit to our department, under conditions of oral calcium and abundant alfacalcidol (3.0 μg/day), laboratory data showed marked hypocalcemia (1.4 mmol/l; albumin-corrected calcium: 1.5 mmol/l), hyperphosphatemia (2.6 mmol/l), and a normal intact PTH level (66 ng/l) with severe vitamin D deficiency (undetectable levels). This evidence concerns the gene PTH and vitamin D deficiency.