EVIDENCE FOR GENETIC-HETEROGENEITY IN THE CARBOHYDRATE-DEFICIENT GLYCOPROTEIN SYNDROME TYPE-I (CDG1)

We have analyzed a series of polymorphic markers on chromosome 16p13 i n 17 families with carbohydrate-deficient glycoprotein syndrome type I (CDG1). First, linkage to the region between D16S406 and D16S500 is c onfirmed. The telomeric border of the candidate region is now definiti vely placed proximal to D16S406 by crossovers observed in 2 families. Second, in 1 family with 2 affected siblings, the disease is not linke d to chromosome 16p. Genetic heterogeneity has not been previously rep orted for CDG1, and this observation has implications for prenatal dia gnosis. Third, allelic associations suggest that the disease locus is localized close to D16S414/D16S497. This places the region of interest centromeric of its published localization. (C) 1996 Academic Press, I nc.