MAPPING OF A DISEASE LOCUS FOR FAMILIAL RAPIDLY PROGRESSIVE FRONTOTEMPORAL DEMENTIA TO CHROMOSOME 17Q12-21

Familial frontotemporal dementia (FTD) is a complex disorder with lack of distinctive histopathological markers found in other types of deme ntia, Most of the linkage reports from FTD families map the disease lo ci to chromosome 17q21-22, However, FTD is genetically heterogeneous, as linkage also has been reported to chromosome 3, In the present stud y, we investigated the genetics of a Swedish family with an early-onse t type of rapidly progressive FTD, associated with muscular rigidity a nd akinetic movements. Neuropathological features such as severe front al lobe degeneration, spongy changes, and gliosis were present in affe cted family members, We here report probable linkage to chromosome 17q 12-21 with a maximum two-point lod score of 2.76 at Theta = 0 for mark er D17S806, and a peak multipoint lod score of 2.86 for the same marke r, Linkage to chromosome 3 was excluded, as two-point lod scores of -2 .79, and -2.27 at Theta = 0.01 for markers D3S1603 and D3S1552, respec tively, were obtained, Sequencing of the translated exons of a strong candidate gene in the linked region of chromosome 17, the tau gene, fa iled to identify any mutations segregating with the disease. (C) 1997 Wiley-Liss, Inc.