Loss of heterozygosity analysis by pyrosequencing. (A) Pyrogram of the coding SNP in the ATM gene (codon 4949) of tumor cells retrieved from patient HD2. Data were obtained by using the 5′-T/CTGACAAC-3′ reverse primer (forward sequence GTTGTCAA/G). (B) Pyrogram of the coding SNP in the ATM gene (codon 4138) of tumor cells retrieved from patient HD4. Data were obtained by using the 5′-T/CATTTTCCAT-3′ foward primer. Pyrograms were obtained by sequential addition of the SNP-specific nucleotides shown beneath each trace.