Hypophosphatemic Rickets Panel

Phosphate is a mineral that is vital to bone growth and maintenance.  Low levels of phosphate in the blood (hypophosphatemia) can lead to abnormalities in bone metabolism.  Rickets is an abnormality of bone mineralization in children, with symptoms including slow growth, short stature, and bone abnormalities including bowing of the legs and genu valgum (knock knees). Rickets may be environmental or hereditary.  Environmental forms of rickets may be due to vitamin D deficiency or abnormal absorption of vitamin D, such as in patients with celiac disease or kidney problems. Hereditary forms of hypophosphatemic rickets may be due to abnormalities of vitamin D metabolism or recognition, or due to a decrease in tubular reabsorption of phosphorus in the kidneys. Additionally, hypophosphatasia, a condition caused by deficient activity of tissue-nonspecific isozyme of alkaline phosphatase (TNSALP), may have rickets as a characteristic in the neonatal, infantile and childhood forms of the disorder. Treatment for hereditary hypophosphatemic rickets may be impacted by identification of an underlying genetic etiology. This panel includes sequence and deletion/duplication analysis of the listed genes.