Novel Mutations Found in Individuals with Adult-Onset Pompe Disease

Area of Science:

• Biochemistry
• Genetics
• Molecular Biology

Background:

• Pompe disease, also known as glycogen storage disease II, is a rare, progressive neuromuscular disorder.
• It results from a deficiency of the acid alpha-1,4-glucosidase enzyme (GAA), leading to skeletal muscle weakness.
• Disease severity and onset timing are influenced by combinations of heterozygous GAA alleles.

Observation:

• Three unrelated patients with adult-onset Pompe disease were analyzed.
• These patients carried the common c.-32-13T>G mutation along with novel mutations: c.2074C>T and c.1910_1918del, and a previously reported c.1082C>G mutation.
• The c.2074 C>T mutation is a nonsense mutation affecting GAA expression, while c.1910_1918del and c.1082C>G are subtler variants with significant impact on GAA activity.

Findings:

• Characterization of two novel mutations (c.2074C>T and c.1910_1918del) and one uncertain variant (c.1082C>G) in Pompe disease patients.
• Molecular and clinical data confirmed the predicted pathogenicity of these GAA gene mutations.
• The study highlights how different types of genetic alterations, even subtle ones, can lead to severe Pompe disease phenotypes.

Implications:

• These findings enhance the understanding of genotype-phenotype correlations in Pompe disease.
• Accurate identification of GAA mutations is crucial for diagnosis and genetic counseling.
• Further research into these mutations may inform the development of targeted therapies for Pompe disease.