Known mutations in the G6PD gene. The full list of known mutations in the G6PD gene can be found in supplemental Table 2. The G6PD genomic gene spans ∼18 kb. Exons are shown as thick numbered blocks and introns as thin lines. Exon 1 (noncoding) and the 3′ untranslated region of exon 13 are in gray. The long intron 2 is indicated by a diagonal double line. Mutations with normal enzyme activity (class IV) are in green. Mutations that cause susceptibility to AHA (class II/III) are in blue. Mutations that cause CNSHA (class I) are in red. Mutations that have been observed only in association with another mutation are in purple. Mutations with unknown clinical features are in in black italics. The amino acid replacements caused by mutations are shown using the amino acid 1-letter symbols. Note the predominance of class I variants in exons 10 and 13. Additional notes: (a) This variant has, in addition to the mutation shown, also the mutation (454 Arg>Cys) of G6PD Union. (b) These variants have, in addition to the mutation shown, also the mutation (126 Asn>Asp) of G6PD A. (c) This variant has been reported to have 3 different mutations: 2 are unique (106 Ser>Lys and 182 Arg>Trp), whereas 1 is the mutation (198 Arg>Cys) of G6PD Coimbra. (d) This variant has been reported to have 3 different mutations: 2 are unique (125 Met>Ile and 127 Ala>Pro), whereas 1 is the mutation (128 Leu>Pro) of G6PD Vanua Lava. (f) This mutation has been found also associated with the mutation (126 Asn>Asp) of G6PD A. (g) These variants have, in addition to the mutation shown, also the mutation (291 Val>Met) of G6PD Viachang. (h) This variant is generated by 2 mutations within the same codon. (i) This variant has 2 unique mutations: 213 Val>Leu and 346 Asn>Ile. (j) This variant has 2 point mutations within the same codon. Δ indicates deletion. ∫, abnormal splicing; Ins, insertion.