text: Yo, listen up, I got something to say,
  'Bout a disorder that goes by GAN, okay?
  Giant axonal neuropathy, rare as can be,
  Autosomal recessive, yeah, that's the key.
  
  Abnormally large axons, dysfunctional too,
  Neuronal problems that'll make you go "Whoa, dude!"
  It's all 'cause of mutations in the GAN gene,
  That's the cause, if you know what I mean.
  
  Now let me break it down for you, Chinese patient in the mix,
  We did a phenotypic assessment, got the fix.
  Used array-based exon capture, targeted sequencing too,
  To find them mutation sites, that's what we do.
  
  The proband's genome showed compound heterozygous mutations,
  S79L and T489S, causing complications.
  S79L was known, T489S, first time reported,
  These changes in the genes, man, they can't be ignored.
  
  Confirmed it in the mother, S79L in the mix,
  And the father had T489S, that's the fix.
  Conserved regions affected, protein structures rearranged,
  This disorder ain't no joke, things be changed.
  
  Sural biopsy showed swollen axons, filled to the brim,
  Closely packed neurofilaments, that's the grim.
  Next-gen sequencing and bioinformatics, the perfect combo,
  To diagnose GAN, that's the way to go.
  
  These compound mutations, S79L and T489S,
  In the GAN gene, causing all the distress.
  We're expanding the knowledge, mutations on the rise,
  Understanding this axonopathy, that's the prize.