Leber Hereditary Optic Neuropathy
Targeted mutation analysis

Genes: MT-ND1, MT-ND4, MT-ND6
Lab method: Sanger sequencing
No of
detectable
markers:		 3 (m.3460G>A, m.11778G>A, m.14484T>C)
TAT: 2-4 weeks
Specimen requirements: 2-4 ml of blood with anticoagulant EDTA

300 ng DNA in TE, AE or pure sterile water at 100-250 ng/µl
The A260/A280 ratio should be 1.8-2.0. DNA sample should be run on an agarose gel as a single band, showing no degradation, alongside with a quantitative DNA marker.
Ordering information: Go to online ordering or download sample submission form

Mitochondrial genome sequencing

Lab method: NGS
Heteroplasmy less than 20% is not detectable by sequencing.
TAT: 2-4 weeks
Specimen requirements: 2-4 ml of blood with anticoagulant EDTA

1 µg DNA in TE, AE or pure sterile water at 100-250 ng/µl
The A260/A280 ratio should be 1.8-2.0. DNA sample should be run on an agarose gel as a single band, showing no degradation, alongside with a quantitative DNA marker.
Ordering information: Go to online ordering or download sample submission form

Indications for genetic testing:

1. Confirmation of clinical diagnosis
2. Genetic counseling

Leber hereditary optic neuropathy (LHON) is characterized by optic nerve dysfunction that leads to   painless, subacute loss of central vision. Disease affects mainly young adult males. LHON is caused by mutations in mtDNA and it is transmitted by maternal inheritance. Approximately 95% of individuals with LHON have one of three point mutations of mitochondrial DNA (m.3460G>A, m.11778G>A, or m.14484T>C).

The prevalence of LHON is estimated to 1:50 000. The m.11778G>A mutation accounts for about 90% of Asian cases and 50 to 70% of Caucasian cases. The m.14484T>C mutation occurs about 86% cases in Quebec, Canada. Frequency of the m.3460G>A mutation is about 20% in European LHON patients.