title: Linkage study of DFNB3 responsible for hearing loss in human.
abstract: BACKGROUND
  Hearing disorders represent a significant health problem worldwide. Recessive inherited cases of the deafness are more prevalent in Pakistan due to consanguineous marriages. Deafness caused by DFNB3 is due to mutation in the gene MYO XVA and its prevalence among Pakistani population is about 5%.
  
  
  METHODS
  Families with at least two or more individual affected with deafness were selected from different areas of District Okara of Pakistan. Six consanguineous families of different ethnic groups having deaf individuals were studied. All these families had three or more deaf individuals in either two or more sib ships. Family history was taken to minimize the chances of other abnormalities. Pedigrees drawn by using Cyrillic software (version 2.1) showed that all the marriages were consanguineous and the families have recessive mode of inheritance. Three STR markers were selected and amplified on all the samples of six families through PCR. The PCR products were then genotyped on non denaturing polyacrylamide gel electrophoresis (PAGE). Haplotypes were constructed to determine the pattern of inheritance and also to determine whether a family was linked or unlinked with known DFNB3 locus.
  
  
  RESULTS
  One out of six families showed linkage to the DFNB3 while rest of the families remained unlinked. Carriers of deafness genes were identified and information was provided to the families on request.
  
  
  CONCLUSIONS
  Knowledge about the genetic causes of deafness provide insight into the variable expression of genes involved in this hereditary problem and may allow the prediction and prevention of associated health problems.
authors: Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
authors: Akhtar
authors: A
authors: Ali
authors: Masroor E
authors: ME
authors: Babar
authors: Saeeda
authors: S
authors: Kalsoom
authors: Jamil
authors: J
authors: Ahmad
authors: Kamran
authors: K
authors: Abbas
keywords: Consanguineous; deafness; linkage analysis; microsatellite markers; polyacrylamide gel electrophoresis