Although Ciona mutants characterized by an impairment in tail extension have been previously described, such mutations are attributable to specific defects in notochord development [23], [24].
These mutations are attributable to diverse types of DNA damage that by genetic or stochastic means escape repair.
It was proposed that direct and indirect interactions often occur between protein pairs whose mutations are attributable to similar disease phenotypes.
Active retrotransposable elements include long interspersed elements (LINEs) and short interspersed elements (SINEs) while approximately 0.27% of all human disease mutations are attributable to retrotransposable elements [ 10].
An analysis of loss-of-heterozygosity (LOH) mutations found that in mouse embryonic stem (ES) cells, the majority of LOH mutations were attributable to nondisjunction, whereas in mouse embryonic fibroblasts, LOH owing to nondisjunction was not observed (Cervantes et al, 2002).
Later studies suggested that the clinical and pathological features of patients with the Arctic mutation are attributable to increased generation of Aβ intermediates formed early in fibrillogenesis, as well as their greater stability [20].
Thus, insofar as previous estimates are reliable, it appears that a substantial portion of the total burden of recessive mutations carried by humans is attributable to single mutations that, when homozygous, lead to sterility or death between birth and reproductive age.
In contrast, in Drosophila melanogaster, only 18% of the genome is composed of TEs, but a high proportion of mutations (more than 50%) is attributable to their transposition [ 4].
Thus, any differences in reporter expression between the wild-type and mutant enhancer constructs is attributable to the Fkh-binding site mutations and not to local positional effects.
It should be noted that not all hereditary breast and ovarian cancer is attributable to mutations in BRCA1 and BRCA2.
