Allele segregation for microsatellite markers in two CDA-II families (1 and 2): the solid squares indicate the affected individuals. The microsatellite markers are tightly linked to the following genes: MANA, mapping on chromosome 5 (5q2.1-2.2); MANAx isozyme, mapping on chromosome 15q25; Gnt-II mapping on chromosome 14q21 and CDAN2 mapping on chromosome 20q11.2.