Article Abstract:
Brachydactyly type B (BDB), the most severe of the brachydactylies, has been linked to chromosome 9q22 and evidence has been found for genetic heterogeneity. A genomewide linkage analysis was carried out with three BDB families, one of which was Portuguese, the others English. The English families had linkage to one region on Chromosome 9 and identical disease haplotype over 18 markers and seem to have the same ancestral mutation. In the Portuguese family linkage to the region was nonexistent, so BDB is genetically heterogeneous. The family had atypical clinical features vs the others. BDB is characterized by hypoplasia or absence of terminal portions of the index-to-little fingers and feet which are affected similarly, but less.
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Article Abstract:
To investigate patterns of genetic recombination in a heterozygous paracentric inversion of chromosome 9q32-q34.3, sperm typing has been carried out using a series of polymorphic microsatellite markers going across the inversion region. Two donors with cytogenticlly normal chromsomes 9 were tested as well, One of them was heterozygous for a pericentric chromosome 2 inversion. Distal to the telomeric breakpoint an increase in recombination was seen in the inversion patient. In the inversion recombination was dramatically lower, but several apparent double recombinants were seen.
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Article Abstract:
Mitochondrial genetic analyses which suggest selection against maternal lineages in bipolar affective disorder (BP) in 25 patients with family histories of disorder suggesting matrilineal inheritance are discussed. No polymorphism identified two or more times showed association of significance with BP in studies using 94 cases with controls.
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