LINKAGE DISEQUILIBRIUM UTILIZED TO ESTABLISH A REFINED GENETIC POSITION OF THE SALLA DISEASE LOCUS ON 6Q14-Q15

Salla disease (SD), an inherited free sialic acid storage disorder, is caused by impaired transport of free sialic acid across the lysosomal membrane. Clinical characteristics of the disease include severe psyc homotor retardation and some neurological abnormalities. We report her e detailed linkage analyses of 50 Finnish SD families that localize th e SD disease gene to a refined chromosomal area on 6q14-q15. The highe st led score of 17.30 was obtained with a microsatellite marker of loc us D6S280. When linkage disequilibrium was adopted in the linkage anal yses, we could further assign the SD locus to the immediate vicinity o f marker locus D6S406. Linkage disequilibrium facilitated further rest riction of the critical chromosomal region to approximately 80 kb, wel l within the limits of positional cloning techniques. (C) 1995 Academi c Press, Inc.