Hereditary chin trembling: a new family with exclusion of the chromosome 9q13-q21 Locus.

Hereditary chin trembling is a rare autosomal dominant condition that has been linked to chromosome 9q13-21 in one kindred. We describe a four-generation family with this condition and, using linkage analysis, have excluded the 9q13-21 region as causing the chin trembling in this family.

Large French-Canadian family with Lewy body parkinsonism: exclusion of known loci.

The identification of rare, large families with Parkinson's disease (PD) has provided important clues that have contributed to our understanding of this complex disorder. We have identified a large French-Canadian kindred that spans five generations consisting of more than 90 individuals. A total of 65 individuals now have been examined, had venous blood drawn, and DNA extracted.