Fig. 2. Distribution of sequence variations along the ryanodine receptor type 1 gene. Exons harboring sequence variations that were detected in this study are represented as solid boxes , in light or dark gray , depending on their location within or outside the hot spots, respectively. Predicted amino acid substitutions written above the exon boxes have been detected in Japan and mainland Asia ( underlined if previously reported in other populations), whereas those below the boxes have been reported in Western countries. Nonsynonymous single nucleotide polymorphisms are indicated in light gray . A list of references corresponding to each sequence variation is available on the Anesthesiology Web site at http://www.anesthesiology.org. †= Detected in this study; ⊙= associated with cores. The occurrence of recurrent substitutions is written between parentheses.