We have not yet been able to definitively identify focal, homozygous
deletions in renal tumor DNA by MLPA (data not
shown). This inability might be related to technical issues
because MLPA is very sensitive to contamination by host
DNA. In 3 of 23 primary clear cell renal carcinomas, however,
we did detect presumptively pathogenic HIF1α mRNA splice variants (absent in normal kidney RNA samples
and absent in publicly available databases), analogous to
those present in renal carcinoma cell lines (Supplementary
Table S2)