PLA2G6 mutation underlies infantile neuroaxonal dystrophy.

Area of Science:

• Neuroscience
• Genetics
• Pediatric Neurology

Background:

• Infantile neuroaxonal dystrophy (INAD) is a rare, fatal, autosomal recessive neurodegenerative disorder.
• Typically presents in infancy with progressive motor and cognitive decline, leading to death by age 10.
• Characterized by diffuse cerebellar atrophy and abnormal iron deposition in the globus pallidum.

Purpose of the Study:

• To investigate the genetic basis of INAD in two unrelated Bedouin Israeli kindreds.
• To identify the specific gene mutation responsible for the disease.
• To elucidate the role of phospholipase in neurodegeneration.

Main Methods:

• Clinical and radiological assessment including brain MRI and magnetic resonance spectroscopy.
• Sural nerve biopsy for diagnostic confirmation.
• Genetic linkage analysis to map the disease locus to chromosome 22q13.1.
• Mutation analysis of the PLA2G6 gene.

Main Results:

• Brain imaging revealed diffuse cerebellar atrophy, globus pallidus iron deposition, and white matter abnormalities.
• Magnetic resonance spectroscopy showed reduced N-acetyl aspartate:chromium ratio, indicating myelination loss.
• Genetic mapping identified a shared locus on chromosome 22q13.1 in affected families.
• A common mutation in the PLA2G6 gene, encoding phospholipase A2 group VI, was identified as the cause.

Conclusions:

• The study identifies mutations in PLA2G6 as the underlying cause of INAD in these families.
• This highlights the critical role of phospholipase A2 group VI in neuronal health and development.
• Findings contribute to understanding the molecular mechanisms of neurodegenerative disorders.