[Juvenile Pompe disease: retrospective clinical study]

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• Pompe disease (glycogen storage disease type II) is an autosomal recessive disorder caused by acid alpha-glucosidase deficiency.
• It is a rare condition with varying prevalence across different populations.
• Clinical presentation exists on a continuum, from infantile to adult-onset forms.

Observation:

• Four patients (two sisters) with juvenile-onset Pompe disease were retrospectively analyzed.
• Disease onset occurred in the second year of life, with diagnosis delays ranging from 2 to 11 years.
• Patients exhibited myopathic features, delayed motor skills, and some had cardiac involvement.

Findings:

• All patients showed increased creatine kinase and aminotransferase levels, progressing to chronic respiratory failure.
• Diagnosis was confirmed by reduced acid alpha-glucosidase activity (<1.5% of normal) and lysosomal glycogen accumulation.
• Genetic analysis revealed various GAA gene mutations, including c.1064T > C homozygosity in one patient.

Implications:

• Pompe disease should be suspected in progressive myopathies, particularly those affecting limb-girdle and respiratory muscles.
• Elevated creatine kinase is a sensitive but non-specific marker for Pompe disease.
• Enzyme replacement therapy showed good tolerance, but long-term outcomes, including survival and functional independence, varied among patients.