Disruption of chromosome 11 in canine fibrosarcomas highlights an unusual variability of CDKN2B in dogs

Background  

In dogs in the western world neoplasia constitutes the most frequently diagnosed cause of death. Although there appear to be similarities between canine and human cancers, rather little is known about the cytogenetic and molecular alterations in canine tumours. Different dog breeds are susceptible to different types of cancer, but the genetic basis of the great majority of these predispositions has yet to be discovered. In some retriever breeds there is a high incidence of soft tissue sarcomas and we have previously reported alterations of chromosomes 11 and 30 in two poorly differentiated fibrosarcomas. Here we extend our observations and present a case report on detail rearrangements on chromosome 11 as well as genetic variations in a tumour suppressor gene in normal dogs.     

Arylsulfatase A pseudodeficiency in Chinese

Arylsulfatase A (ASA) pseudodeficiency was found to be much rarer in Taiwan than in most western countries (2.5% versus 7.3%–20% carrier rate). The linkage of two mutations (A2725G and A1788G) in the pseudodeficiency allele was preserved in Chinese, and A2725G did not occur alone. This unusual linkage of mutations has not been fully explained previously because the frequency of A2725G alone was not clear (as low as 4% in the only report). However, A1788G was found in 55 of 160 (34.4%) DNA samples tested in this study. These data suggest that the A2725G mutation occurred in DNA that already contained the A1788G change, at an ancient time in one of our common ancestors.