MedGen

A noncongenital process of hair loss, which may progress to partial or complete baldness. [from HPO]

A form of primary hypertrophic osteoarthropathy with characteristics of delayed closure of the cranial sutures and fontanelles, digital clubbing, arthropathy, and periostosis. To date, about 30 cases have been reported. May also be associated with congenital heart disease. It is caused by mutations in the HPGD gene (4q33-q34) and is inherited as an autosomal recessive trait. [from SNOMEDCT_US]

Vitamin D-dependent rickets type 2A (VDDR2A) is caused by a defect in the vitamin D receptor gene. This defect leads to an increase in the circulating ligand, 1,25-dihydroxyvitamin D3. Most patients have total alopecia in addition to rickets. VDDR2B (600785) is a form of vitamin D-dependent rickets with a phenotype similar to VDDR2A but a normal vitamin D receptor, in which end-organ resistance to vitamin D has been shown to be caused by a nuclear ribonucleoprotein that interferes with the vitamin D receptor-DNA interaction. For a general phenotypic description and a discussion of genetic heterogeneity of rickets due to disorders in vitamin D metabolism or action, see vitamin D-dependent rickets type 1A (VDDR1A; 264700). [from OMIM]