Extended Data Fig. 3. Early copy number gains in brain cancers.
a, Three illustrative examples of glioblastoma with trisomy 7. The red arrow depicts the expected VAF cluster of point mutations preceding trisomy 7, which usually contains less than three SNVs. b, Distributions of the number of SNVs preceding trisomy 7 and total number of mutations on chromosome (chr) 7 in n = 34 GBM samples with trisomy 7. c, Medulloblastoma example with isochromosome 17q. d, Distributions of SNVs on 17q in n = 95 samples with isochromosome 17q; 74 out of 95 samples have less than 1 SNV preceding the isochromosome.