text: Yo, check it out, here's the deal
  We got two babies, perinatal lethal osteogenesis imperfecta, for real
  In one fam, they got the same new dominant point mutation
  But hold up, it wasn't found in the dermal fibroblast DNA examination
  
  But yo, we found it in the father's hair root bulbs and lymphocytes
  And guess what? It was even in his sperm, that's tight
  Mosaicism in the germ line, that's the key
  Explains why the condition recurred, you see
  
  This mutation, it happened before the germ-line
  And somatic cell progenitors started to align
  Around one in eight sperm, they carry the mutation
  So at least four progenitor cells, they're in rotation
  
  Now here's the kicker, pay attention to this fact
  The person with the mosaic, they're clinically intact
  Genetic diseases, man, they got a dual nature
  Both qualitative and quantitative, it's a complex feature