Kathleen M. Falls

Update on the search for DNA markers linked to manic-depressive illness in the old order amish

In this report we describe our efforts to identify a gene involved in bipolar illness using a large, multigenerational Old Order Amish pedigree with many affected individuals. The original collection of cell lines from Amish pedigree 110 has been extended to include 169 individuals. We have used over 250 markers spaced at approximately 20 centiMorgans that detect restriction length fragment polymorphisms, but no LOD scores greater than 3 have been obtained from pairwise linkage analyses. We are expanding our collection of cell lines from both normal and affected family members and updating our diagnostic data as we continue our systematic screening of the genome for a gene involved in bipolar illness.

Framework multipoint map of the long arm of human Chromosome 4 and telomeric localization of the gene for FSHD

Mapping the long arm of Chromosome (Chr) 4 has assumed medical relevance with the establishment of linkage of facioscapulohumeral muscular dystrophy (FSHD) to distal 4q markers. We have constructed a multipoint linkage map using DNA markers that map to the long arm of Chr 4. Segregation data were collected for 17 DNA markers on the multigenerational CEPH mapping families, and data for one marker were taken from the published CEPH database. Genotypic information for six of these markers was also collected from a set of 24 families that exhibited inheritance of FSHD. Multipoint analyses allowed us to construct a map of 12 loci, connecting two previously separate linkage groups. Significant sexspecific differences in recombination were found for some genetic intervals. Four loci from the distal region of this map showed linkage with FSHD. A map using these terminal markers gave the strongest support for FSHD in the most distal position over all other possible positions.