JAMA : the journal of the American Medical Association
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To examine more closely the association between apolipoprotein E (APOE) genotype and Alzheimer disease (AD) by age and sex in populations of various ethnic and racial denominations. ⋯ The APOE epsilon4 allele represents a major risk factor for AD in all ethnic groups studied, across all ages between 40 and 90 years, and in both men and women. The association between APOE epsilon4 and AD in African Americans requires clarification, and the attenuated effect of APOE epsilon4 in Hispanics should be investigated further.
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There is a substantial risk of a second cancer for persons with hereditary retinoblastoma, which is enhanced by radiotherapy. ⋯ Genetic predisposition has a substantial impact on risk of subsequent cancers in retinoblastoma patients, which is further increased by radiation treatment. A radiation dose-response relationship is demonstrated for all sarcomas and, for the first time in humans, for soft tissue sarcomas. Retinoblastoma patients should be examined for new cancers and followed into later life to determine whether their extraordinary cancer risk extends to common cancers of adulthood.
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Susceptibility to multiple sclerosis (MS) involves a genetically complex autoimmune component. However, except for genes in the HLA system, specific susceptibility loci are unknown or unconfirmed. ⋯ The significant chromosome 19q13.2 single-locus and multilocus haplotype associations with MS in Caucasian and Chinese patient samples indicate an effect from a nearby disease susceptibility locus. These initial observations are an encouraging step toward the description of non-HLA genetic susceptibility to MS.