Loss of heterozygosity on the X chromosome in human breast cancer.
The analysis of loss of heterozygosity (LOH) in tumours can be a powerful tool for mapping the sites of tumour suppressor genes in the human genome. A panel of breast cancer patients was assembled as pairs of tumour and lymphocyte DNA samples and LOH studies carried out by Southern hybridisation with polymorphic loci mapping to the X chromosome with appropriate controls. Deletion mapping revealed a high frequency of small regionalised deletions, defining at least three independent regions, one of which is particularly well mapped to a 500 kb stretch of DNA in the distal portion of the pseudoautosomal region of Xp. A second region has been identified within the pseudoautosomal region close to the pseudoautosomal boundary, and there is a third discrete site of loss on distal Xq. Perturbations of sequences at these regions represent independent events in a number of patients. This study represents the first detailed analysis of LOH on the X chromosome in human breast tumours, the results of which indicate that at least three regions of this chromosome are involved in the disease.
Loupart
M L
ML
ICI/University Joint Laboratory, University of Leicester, United Kingdom.
Adams
S
S
Armour
J A
JA
Walker
R
R
Brammar
W
W
Varley
J
J
D000483:Alleles; D001943:Breast Neoplasms / Q000235:genetics*; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D005260:Female; D005819:Genetic Markers; D006579:Heterozygote; D006801:Humans; D011110:Polymorphism, Genetic; D014960:X Chromosome / Q000235:genetics*
D005819:Genetic Markers