Guest Blogger Danio, one last time:
The current standard of pediatric care mandating that all newborns undergo hearing screenings has been applied successfully throughout much of the industrialized world. Early identification of hearing impairments gives valuable lead-time to parents and health care providers during which they can plan medical and educational interventions to improve the child’s development, acquisition of language skills, and general quality of life.
Up to 12% of children born with hearing loss have Usher syndrome. However, diagnosing Usher syndrome as distinct from various forms of congenital hearing impairment is often impossible until the onset of retinal degeneration years later. The considerable number and size of the genes involved makes genetic screening impractical with the current methods, unless there is a family or community history that can shorten the list of targets by implicating a particular Usher gene or subtype.
The educational and medical interventions undertaken to improve a deaf or hearing-impaired child’s cognitive and social development can vary extensively, based in part on whether the child in question is expected to lose his or her vision later in life. Thus an earlier diagnosis of Usher syndrome is an immediate and critical research goal. The most imminent hope for such a diagnostic advance lies in gene chip screening. With this technology, the patient’s DNA can be screened against a microarray of human genes known to cause deafness (and/or Usher syndrome) when mutated, and variances in the DNA sequence of any screened gene would be detected and analyzed. One such chip is already available for commercial use, and another appears to be approaching clinical availability. The rapid and affordable analysis these microarrays offer will be of tremendous benefit in the early diagnosis and management of Usher syndrome.