The gene responsible for pseudohypoparathyroidism type I b is paternally imprinted and maps in four unrelated kindreds to chromosome 20q13.3. - Juppner,H.; Schipani,E.; Bastepe,M.; Cole,D.E.; Lawson,M.L.; Mannstadt,M.; Hendy,G.N.; Plotkin,H.; Koshiyama,H.; Koh,T.; Crawford,J.D.; Olsen,B.R.; et al. (Proc Natl Acad Sci U S A, 1998)