Example of allele segregation for the markers under study in two representative CDA II families (CDAGE and CDACE): the solid squares and circles indicate the affected individuals. The microsatellite markers are tightly linked to the following candidate genes: α-Man II, mapping on chromosome 5 (5q2.1-2.2); α-Man IIx isozyme, mapping on chromosome 15q25; and human GnT II, mapping on chromosome 14q21. The above-mentioned markers are listed according to the order established in Weissenbach et al21 and Gyapay et al.22