Genomic DNA was extracted from 5 ml whole blood by protein
salting out and nucleic acid precipitation (15). For patients who
were deceased at the time of the study (patients III.3 and III.9)
genomic DNA was obtained from the normal tissue portions
of formalin-fixed, paraffin-embedded (FFPE) tumor blocks using
the RecoverAll Total Nucleic Acid Isolation Kit for FFPE (Life
Technologies, Grand Island, NY). Exons 1–17 of the BAP1
gene (NCBI Reference Sequence: NM_004656.3) were amplified
employing a PCR protocol adapted from Wiesner et al.
(9); Sanger sequencing of amplified fragments in forward and
reverse directions was performed by Genewiz (La Jolla, California).
Electropherogram results were analyzed and mutations
identified using Mutation Surveyor 2.61.