Alexander disease: a leukodystrophy caused by a mutation in GFAP

Area of Science:

• Neuroscience
• Genetics
• Rare Diseases

Background:

• Alexander disease is a rare, fatal central nervous system disorder.
• It leads to progressive motor and mental function loss.
• Previously, its etiology was largely unknown, with most cases being sporadic and untreatable.

Purpose of the Study:

• To investigate the genetic underpinnings of Alexander disease.
• To identify the cause of sporadic and familial cases.
• To understand the mutation patterns associated with different forms of the disease.

Main Methods:

• Genetic analysis of affected individuals and their families.
• Mutation screening of the glial fibrillary acidic protein (GFAP) gene.
• Comparison of mutation types across infantile, juvenile, and adult-onset forms.

Main Results:

• Overwhelmingly, Alexander disease cases exhibit a dominant mutation in one allele of the GFAP gene.
• This mutation results in an amino acid substitution.
• In rare adult-onset cases, the mutation may be inherited; however, most mutations arise spontaneously, likely in parental germ cells.

Conclusions:

• The GFAP gene mutation is the primary cause of most Alexander disease cases.
• Spontaneous mutations are the predominant origin, rather than inheritance.
• Understanding the genetic basis opens avenues for future research into potential treatments.