X-linked deafness: De novo deletion of a cosmid using dosage studies
- Institute of Child Health, London (United Kingdom)
- University Hospital of Nijmegen (Netherlands); and others
We have used three polymorphic microsatellite repeats at Xq21, (DXS986, DXS995 and DXS1002) to test for linkage in families with X-linked deafness. Close linkage was demonstrated between all three markers and the disease locus in families with and without a bony abnormality on the CT scan. DXS995 gave a maximum two point lod score of l0.37 with no recombinations. This marker was used to type an additional small sibship. Analysis showed that the two brothers, one deaf and one hearing, both inherited the same maternal allele indicating either the first recombination seen to date or a de novo mutation in the proband. Using a cosmid from the critical region, a deletion was detected in the proband of this sibship. By using a phoshorimager, dosage of an EcoR1 fragment from this cosmid and a control probe was compared to normal subjects and obligate carriers from another family with a similar deletion. Results show that the mother of this isolated case does not carry the deletion, confirming that it is de novo. These markers may be useful for carrier ascertainment in families with a radiological change on CT scan or a pedigree which is linked to Xq21.
- OSTI ID:
- 133985
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0720
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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