Leber's hereditary optic neuropathy: Diagnostic pitfalls in genetic testing

Area of Science:

• Ophthalmology
• Genetics
• Neurology

Background:

• Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease causing vision loss.
• Accurate genetic testing is vital for diagnosing LHON.
• Misinterpretation of genetic tests can lead to incorrect diagnoses.

Purpose of the Study:

• To investigate the occurrence and impact of false positive genetic testing for LHON.
• To evaluate the necessity of repeated testing in suspected LHON cases.

Main Methods:

• Analysis of three suspected LHON cases with initial RFLP and sequencing.
• Re-evaluation of initial DNA samples by the testing laboratory.
• Clinical assessment by a specialized neuro-ophthalmology center.

Main Results:

• Initial genetic analyses misinterpreted results, indicating rare mutations.
• Re-evaluation confirmed no typical LHON mutations in any of the three patients.
• The diagnosis of LHON was averted due to careful re-examination.

Conclusions:

• A high index of suspicion is necessary when rare mutations are detected.
• False positive genetic testing results are possible.
• Confirmation of positive LHON tests by an independent laboratory is recommended, particularly if clinical signs are atypical.