Objective:

To report a case of childhood onset autosomal recessive Leber Hereditary Optic Neuropathy (arLHON).

Background:

The vast majority of LHON cases are maternally inherited through mitochondrial DNA and displays incomplete penetrance with significant preference for males. Recent studies show the prevalence of arLHON to be 1.09 per million individuals compared to mitochondrial LHON (mtLHON), which is approximately 1 in 25,000.

Design/Methods:

This is a unique case of a young girl who presented with subacute onset vision loss, ultimately diagnosed with arLHON.

Results:

An 8-year-old healthy girl presented to the Neuro-ophthalmology clinic for evaluation of vision loss that occurred 1 year ago. Optical coherence tomography (OCT) at that time showed thickened retinal nerve fiber layer (RNFL). She underwent IV steroid treatment for presumed optic neuritis but did not have any improvement. One year later, she had decreased best corrected visual acuity to count fingers of the right eye and 20/150 of the left eye. Exam showed optic disc pallor and OCT confirmed bilateral optic atrophy. Labs for common treatable causes of optic neuropathy including CNS demyelinating panel were unrevealing. MRI brain and orbits showed bilateral optic nerve atrophy without abnormal enhancement. Whole genome sequencing ultimately revealed homozygous pathogenic variant in the DNAJC30 gene, which has been reported to cause arLHON. Previously identified pedigrees of arLHON have demonstrated incomplete penetrance with significant male predominance, similar to mitochondrial LHON. Key differences include earlier age of onset in arLHON as well as higher rates of clinically relevant visual recovery with idebenone, which our patient was started on.

Conclusions:

LHON inheritance can be mitochondrial or autosomal recessive and should be considered in young patients who present with subacute vision loss, optic edema or atrophy, and negative workup for common causes of optic neuropathy. Idebenone can be considered as a treatment, especially given superior response in arLHON.