Lecture Notes

Fukuyama Disease (Fukuyama Congenital Muscular Dystrophy)

• Overview
  • Fukuyama disease is a congenital muscular dystrophy primarily affecting muscles, brain, and eyes.
  • First described by Yukio Fukuyama in 1960.
  • Common in Japan but rare in other populations.
• Genetics and Inheritance
  • Autosomal recessive inheritance pattern.
  • Caused by mutations in the FKTN gene on chromosome 9q31-33.
  • FKTN gene encodes fukutin, involved in glycosylation of alpha-dystroglycan, essential for muscle and brain integrity.
• Clinical Features
  • Muscular
    • Severe generalized muscle weakness, evident at birth or early infancy.
    • Marked hypotonia and delayed motor milestones.
    • Progressive muscle wasting and contractures, particularly affecting lower limbs.
  • Neurological
    • Significant developmental delay and intellectual disability.
    • Seizures in approximately 50% of cases.
    • Microcephaly (small head size) frequently observed.
  • Ocular
    • Eye abnormalities include retinal dysplasia, optic nerve hypoplasia, and cataracts.
    • Visual impairment ranges from mild to severe.
  • Other Systemic Manifestations
    • Cardiac involvement: cardiomyopathy, arrhythmias.
    • Respiratory complications due to muscle weakness.