Abnormal Regulation of Circulating 25-Hydroxyvitamin D in the Williams Syndrome

THE Williams syndrome is characterized by the triad supravalvular aortic stenosis, mental retardation, and an elfin facies.^1,2 In addition, mild microcephaly, neurologic dysfunction, hallux valgus, hernias, pectus excavatum, and other congenital cardiac and vascular defects may be present. The unique facies is characterized by a medial eyebrow flare, short palpebral fissures, ocular hypotelorism, a depressed nasal bridge, periorbital fullness, strabismus, blue eyes, a stellate pattern in the iris, prominent lips, and molar hyperplasia.² The syndrome is often associated with idiopathic hypercalcemia of infancy, which usually occurs in the first year of life.^{3 4 5 6 7 8 9 10 11} Patients have increased sensitivity to vitamin D.^5,6 Balance.