Canavan disease: a monogenic trait with complex genomic interaction.

Area of Science:

• Neuroscience
• Genetics
• Biochemistry

Background:

• Canavan disease (CD) is an inherited leukodystrophy caused by aspartoacylase (ASPA) deficiency, leading to N-acetylaspartic acid (NAA) accumulation in the brain.
• Over 40 ASPA gene mutations are known, with two founder mutations prevalent in Ashkenazi Jewish populations, indicating a carrier frequency of approximately 1/40.
• ASPA deficiency disrupts myelin and causes spongy degeneration of brain white matter, presenting with macrocephaly, developmental delay, and neurological impairment.

Purpose of the Study:

• To investigate the complex genomic interactions and pathophysiological basis of Canavan disease using a knockout mouse model.
• To evaluate the potential of gene therapy for Canavan disease.

Main Methods:

• Generation and analysis of a Canavan disease knockout mouse model.
• Microarray expression analysis to identify gene expression changes in the affected brain.
• Adeno-associated virus (AAV)-mediated gene transfer of the ASPA gene in the mouse brain.

Main Results:

• The knockout mouse model exhibited genomic interactions, including altered glutamate and GABA levels, and changes in GABA-A receptor (GABRA6) and glutamate transporter (EAAT4) expression.
• Upregulation of the Spi2 gene, involved in apoptosis, was observed.
• ASPA gene transfer in the mouse brain demonstrated encouraging results, with improved myelination and reduced spongy degeneration both at and beyond the injection site.

Conclusions:

• Canavan disease involves complex gene interactions leading to brain degeneration and neurological deficits.
• ASPA gene therapy using AAV vectors shows therapeutic potential for Canavan disease, warranting further investigation.