Which condition is primarily caused by a deficiency in renal cells of 1-α-hydroxylase?

The condition primarily caused by a deficiency in renal cells of 1-α-hydroxylase is Vitamin D-dependent rickets Type 1. This enzyme, 1-α-hydroxylase, plays a crucial role in converting 25-hydroxyvitamin D (the inactive form of vitamin D) into its active form, calcitriol (1,25-dihydroxyvitamin D), within the kidneys. This active form of vitamin D is essential for calcium and phosphate metabolism, which are vital for maintaining healthy bone structure.

In Vitamin D-dependent rickets Type 1, the lack of 1-α-hydroxylase leads to an inability to produce sufficient levels of calcitriol, resulting in impaired calcium absorption from the intestine and consequent rickets. The hallmark features of this condition include hypophosphatemia and hypocalcemia, leading to the characteristic bone deformities seen in rickets.

Other options may represent different mechanisms or deficiencies not directly caused by the lack of 1-α-hydroxylase. For example, hypoparathyroidism involves low levels of parathyroid hormone, impacting calcium and phosphate regulation but not directly via the vitamin D metabolic pathway. Vitamin D-resistant r