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Evidence for a novel x-linked modifier locus for leber hereditary optic neuropathy
Suma P Shankar1, John H Fingert, Valerio Carelli
1Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA.
Ophthalmic Genetics
|March 26, 2008
Summary
Leber Hereditary Optic Neuropathy (LHON) is a blinding disease. This study identified a new genetic susceptibility locus on the X chromosome, suggesting X-linked modifiers contribute to LHON development.
Area of Science:
- Genetics
- Ophthalmology
- Mitochondrial Diseases
Background:
- Leber Hereditary Optic Neuropathy (LHON) is a maternally inherited optic nerve disease.
- Incomplete penetrance and male predominance suggest modifying factors influence LHON.
- Previous studies indicated nuclear genes and environmental factors are crucial for LHON manifestation.
Purpose of the Study:
- To investigate X-chromosomal linkage in a Brazilian family with LHON.
- To identify novel susceptibility loci for LHON on the X chromosome.
Main Methods:
- Performed X-chromosomal linkage analysis.
- Analyzed a large Brazilian family with a G11778A mitochondrial DNA mutation (mtDNA) on a haplogroup J background.
Main Results:
- Identified a novel LHON susceptibility locus on chromosome Xq25-27.2.
- Achieved multipoint non-parametric linkage scores > 5.00 (P = 0.005).
- Observed a maximum two-point non-parametric linkage score of 10.12 for marker DXS984 (Xq27.1).
Conclusions:
- These findings suggest genetic heterogeneity for X-linked modifiers of LHON.
- The X chromosome plays a significant role in modulating LHON disease expression.
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