Going by experience, is have to say age is major attribute.
<span>Chromosomal and genetic causes:
Muscular dystrophy, sickle cell anemia, hemophilia, cystic fibrosis
CHARGE Association (syndrome) and Usher syndrome are the two examples of genetic causes of deaf-blindness
-Teratogenic causes:
TORCH - toxoplasmosis, other, rubella, cytomegalovirus, and herpes.
-Prematurity and pregnancy complications:
Neurological conditions, cerebral palsy -(tongue and mouth cant move to articulate), vision or hearing loss, intellectual disability
-Acquired causes:
Traumatic brain injury (TBI), child abuse, environmental toxins</span><span>Topographical </span>
DNA polymerase is the answer. Hope it helps. Cheers mate
