Figure 1: The NF1 analysis results of the patient. CHIPS analysis was performed either 58°C or 60°C annealing temperature series. Cleaved heteroduplex bands are indicated by black arrow heads and shifted bands by heteroduplex formations are indicated by white arrow heads (A). Novel NF1 nonsense mutation, Gln209* was detected in exon 6 (B). To distinguish PCR slippage error by poly T/A stretch from real polymorphism, compared CHIPS results of the patient and hemizygous control (large NF1 deletion) for exon 7, 14, 25 and 42. Unique cleavage bands (*) are detected in exon 7 and 14, but not in exon 25 and 42 (C). M, molecular weight marker; U, undigested control of PCR product; C, cleaved PCR product with SURVEYOR Nuclease S.