Locus heterogeneity
Locus heterogeneity occurs when mutations at multiple genomic loci are capable of producing the same phenotype (ie. a single trait, pattern of traits, or disorder), and each individual mutation is sufficient to cause the specific phenotype independently.[1] Locus heterogeneity should not be confused with allelic heterogeneity, in which a single phenotype can be produced by multiple mutations, all of which are at the same locus on a chromosome.[1] Likewise, it should not be confused with phenotypic heterogeneity, in which different phenotypes arise among organisms with identical genotypes and environmental conditions.[2] Locus heterogeneity and allelic heterogeneity are the two components of genetic heterogeneity.[3]
Locus heterogeneity may have major implications for a number of human diseases. For instance, it has been associated with retinitis pigmentosa,[4] hypertrophic cardiomyopathy,[5] osteogenesis imperfecta,[6] familial hypercholesterolemia,[7] and hearing loss.[8] Heterogenous loci involved in formation of the same phenotype often contribute to similar biological pathways.[1] The role and degree of locus heterogeneity is an important consideration in understanding disease phenotypes and in the development of therapeutic treatment for these diseases.[1]
The detection of causal genes for diseases impacted by locus heterogeneity is difficult with genetic analysis methods such as linkage analysis and genome sequencing.[9] These methods rely on comparison of affected family members, but when different family members have different disease-causing genes, such genes may not be accurately identified.[9] Existing techniques have been modified and new techniques have been developed to overcome these challenges.[9][10][11]
Retinitis pigmentosa
Retinitis pigmentosa is a condition that causes damage to the light-sensitive cells of the retina.[12] There have been over 60 genes identified whose mutations independently cause retinitis pigmentosa, and these can be inherited in an autosomal dominant, autosomal recessive, or X-linked pattern.[13] Examples of such genes include the rhodopsin gene (RHO), the gene encoding for retinitis pigmentosa GTPase regulator (RGPR), and the gene encoding retinitis pigmentosa 2 protein (RP2).[14]
See also
References
- ^ PMID 25538735.
- S2CID 29846214.
- ^ "NCI Dictionary of Genetics Terms". National Cancer Institute. 2012-07-20. Retrieved 2019-11-27.
- PMID 23701314.
- PMID 1975599.
- PMID 24715559.
- PMID 236556.
- PMID 9927480.
- ^ PMID 25491636.
- S2CID 25856694.
- S2CID 46285173.
- S2CID 24950783.
- ^ "RetNet: Summaries". sph.uth.edu. Retrieved 2019-11-27.
- PMID 22131869.
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