Duchenne Muscular Dystrophy

Duchennemuscular dystrophy (DMD) is a severe, X-linked, progressive neuromuscular disease caused by mutations in the DMD gene. DMD impacts approximately one in 3500 to 5000 males born worldwide. Early symptoms manifest around the age of 1 , with loss of ambulation by the mean age of 12 and mean life expectancy of just 26 years.  Until now, there is no cure for DMD.

Duchenne Muscular Dystrophy

  • Progressive muscle weakness
  • Gait abnormalities and frequent falls
  • Cardiac and respiratory failure in the late stage

Epidemics

Duchenne muscular dystrophy affects one individual among 3500-5000 new male birth. Although primarily an X-linked condition affecting males, some female carriers are symptomatic for the disorder but usually exhibit a milder phenotype. Large mutations in DMD gene are the major mutations in all territories

Dystrophin gene and protein

DMD gene is the longest known human gene, spanning over 2.4Mbp, accounting for approximately 1.4% of the X chromosome. It comprises 79 exons, with a coding region length of 11,058 bp. Dystrophin protein has several different isoforms. In heart and skeletal muscles, a 427kd dystrophin protein is the major isoform.

Base Editing Therapy in DMD

Base editing can precisely edit the bases on the mutated DMD gene and recover the DMD protein expression through exon skipping. Through repairing the DMD gene, base editor medicine can provide a cure for DMD therapy.