Determining Genetic Risk

Case 4 - Hypophosphatemic Rickets

Family history:

Mrs. Wright presents to the genetics clinic concerned that the Vitamin D resistant rickets in her family may be genetic. Mrs. Wright has decreased seurm phosphorus, but no bony abnormalities. Her father had bowed legs as do two of her sisters. She has a brother who is unaffected and normal serum levels of phosphorus. Her youngest affected sister has four children. She has 2 boys and 2 girls. Of these children, a daughter, has hypophosphotemia and bowed legs. One son has bowed legs and short stature. The other two children are unaffected.

Mrs. Wright also has four children, 2 boys and 2 girls. She reports that one of her sons and one of her daughters had hypophosptetemia and short stature. Attending the appointment with her is her granddaughter. This granddaughter is the child of her affected son. This young lady has bowed legs.

Given the clinical features and the family history you suspect autosomal dominant Vitamin D resistant rickets.