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Genetics terms & Dzs
Genetics terms and diseases that matter
Question | Answer |
---|---|
Variable expression | Nature and severity of phenotype vary from person to person with the same mutation (NF1) |
Incomplete penetrance (incomplete penetance) | Some individuals with mutation have the disease Some individuals with the mutation don't have the disease. |
Pleitropy | 1 gene causes many phenotypic changes (Phenylketonuria) |
Dominant negative mutation | mutant, non-functional gene, inhibits production of normal, functional gene |
Linkage disequalibrium | 2 linked loci occur together more often than expected |
Locus Heterogeneity | Mutations at different loci can produce the same phenotype (Marfans, MEN2B, homocystinuria all cause marfan habitus) |
Heterplasmy | Mosaicism of mutant and normal mitochondrial DNA |
Uniparental disomy | receiving both copies of one gene from the same parent |
Imprinting | Differences in phenotype depend on whether the mutation is of maternal or paternal origin (Prader-Willi or Angelman's syndrome) |
Mental retardation, hyperphagia, obesity, hypogonadism, hypotonia | Prader-Willi syndrome. Deletion of normally active Paternal Allele on Chr. 15 |
Mental retardation, seizures, ataxia, inappropriate laughter ("happy puppet") | Angelman's syndrome. Deletion of normally active Maternal Allele on Chr. 15 |