Severe retinal degeneration in a patient with Canavan disease

ABSTRACT

Background: Canavan disease is an autosomal recessive, neurodegenerative disorder caused by mutations in ASPA, a gene encoding the enzyme aspartoacylase. Patients present with macrocephaly, developmental delay, hypotonia, vision impairment and accumulation of N-acetylaspartic acid. Progressive white matter changes occur in the central nervous system. The disorder is often fatal in early childhood, but milder forms exist.

Materials and methods: Case report.

Results: We present the case of a 31-year-old male with mild/juvenile Canavan disease who had severe vision loss due to a retinal degeneration resembling retinitis pigmentosa. Prior to this case, vision loss in Canavan disease had been attributed to optic atrophy based on fundoscopic evidence of optic nerve pallor. Investigations for an alternative cause for our patient’s retinal degeneration were non-revealing.

Conclusion: We wonder if retinal degeneration may not have been previously recognized as a feature of Canavan disease. We highlight findings from animal models of Canavan disease to further support the association between Canavan disease and retinal degeneration.

KEYWORDS:

• Canavan disease
• N-acetylaspartic acid
• ASPA
• retinal degeneration
• electroretinography

Acknowledgments

J.O. Sass gratefully acknowledges financial support by the program ‘FH Zeit für Forschung’ (project ‘KETOplus’, 005–1703-0016) of the Ministry of Culture and Science of the German State of North Rhine-Westphalia and by the Jürgen Manchot Stiftung (Düsseldorf, Germany). He thanks Dr. Anke Sommer for the preparation of the expression vector with the ASPA reference sequence.

M.D. Benson is kindly supported by the Clinician-Scientist Emerging Leader Award from Fighting Blindness Canada (FBC).

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This work was supported by the FH Zeit für Forschung [005–1703-0016]; Fighting Blindness Canada [Clinician-Scientist Emerging Leader Award].