Pakistan Research Repository


Naz, Sadaf (2001) STUDY OF NON-SYNDROMIC RECESSIVE DEAFNESS BY LINKAGE ANALYSIS. PhD thesis, University of the Punjab, Lahore.



To initiate a study on molecular characterization of non-syndromic recessive deafness in the Pakistani population, thirty-five consanguineous families of different ethnic groups were enrolled. Twenty-eight families with three or more affected individuals were analyzed for linkage to all known non-syndromic recessive deafness causing loci and seven of the unlinked families from this group were also screened for dominant and Usher syndromes loci. These screening studies led to the mapping of different deafness genes. Fourteen families showed linkage to the known non-syndromic recessive deafness loci. Carriers of deafness genes were identified and information was provided to the families on request. DFNB3 was found to segregate in a maximum number of families (8.5%). Linkage analysis led to the recognition of Pendred syndrome in one family previously thought to have non-syndromic deafness. DNA sequencing analyses revealed novel mutations in the PDS gene for this and some other PDS linked families. These included 3 missense and one splice site mutation. A novel mutation in TECTA, 6037delG was identified in one of the families showing linkage to DFNB21. This is the second mutation in TECTA causing non-syndromic recessive deafness. One family was linked to a non-syndromic recessive deafness locus at chromosomal interval 3q24-25. This appears to be a narrowed refinement of one of the DFNB15 loci and/or it may be an allelic variant to USH3. A novel non-syndromic deafness causing gene, DFNB29 was mapped to chromosome 21q22. DFNB8/10 were excluded as a case of deafness for this family. The candidate deafness gene interval was reduced to ~1.5 cM by screening this family for recombination events. Twelve families remained unlinked to the mapped chromosomal intervals for deafness genes, indicating that they may have some novel deafness causing genes

Item Type:Thesis (PhD)
Uncontrolled Keywords:hearing pathway, deafness, syndromic deafness, phenocopy trait, syndromic loci, usher syndromes loci, tecta
Subjects:Biological & Medical Sciences (c) > Biological Sciences(c1) > Biology (c13)
ID Code:530
Deposited By:Mr. Muhammad Asif
Deposited On:11 Aug 2006
Last Modified:04 Oct 2007 21:01

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