Intrafamilial "DOA-plus" phenotype variability related to different OMI/HTRA2 expression.

Area of Science:

• Genetics
• Neuroscience
• Mitochondrial Biology

Background:

• Dominant Optic Atrophy and Deafness (DOAD) is a condition that can present with a range of neurological symptoms, termed "DOA-plus".
• Phenotypic variability is common in "DOA-plus" patients, even those with the same OPA1 gene mutation.

Observation:

• Two families with "DOA-plus" shared the same OPA1 mutation (c.1334G>A, p.Arg445His) but exhibited distinct clinical, pathological, and biochemical profiles.
• Differential expression levels of the mitochondrial OMI/HTRA2 molecule were observed between the two patients.

Findings:

• The OPA1 gene mutation did not result in a uniform "DOA-plus" phenotype in the studied families.
• Mitochondrial OMI/HTRA2, a stress sensor, showed varying expression levels in patients with the same OPA1 mutation.

Implications:

• The findings suggest OMI/HTRA2 may function as a modifier gene, influencing the diverse clinical manifestations of "DOA-plus".
• Further research into OMI/HTRA2's role could elucidate mechanisms behind "DOA-plus" phenotype variability and inform potential therapeutic strategies.