Somatic copy-number alterations in mother's and child's tumors. (A) Copy-neutral LOH was observed in most chromosomes in the child's tumor, but chromosome gains were also prevalent. In the mother, there was a copy-neutral LOH in Chr 17p.3 and a hemizygous deletion in Chr X. In the chromosomal counts figure for the child, A represents a genomic region inherited from the mother and B a genomic region inherited from the father. Normal chromosomal count is thus marked with AB and, for example, copy-neutral LOH in either paternal or maternal chromosomal region is marked with AA/BB. If a tumor contains two subclones with different counts for a genomic region, the chromosomal counts for each subclone are separated with a + sign. (B) A region in Chr 22q11.23 was homozygously deleted in both tumor samples obtained from the child. Genes falling within this region, including SMARCB1/hSNF5/INI1, are visualized in the figure.