TABLE 2

Porphyrin transport and non-synonymous polymorphisms of ABCG2

Transport of hematoporphyrin and MTX is indicated by either + (positive) or – (negative). Allele frequencies are summarized from previously reported SNP data on human ABCG2. There are differences in the allele frequency of the polymorphisms among different ethnic groups.

Potential Risk Amino Acid Transport Allele Frequency cDNA Position Located on Exon Allele Data Sourcea
Hemato MTX Wild-Type Allele
%
V12M ++ ++ 2.0-90.0 34 2 G A 1, 2, 4, 5, 7, 8
★★ Q126stop - - 0.0-1.7 376 4 C T 1, 3, 5, 7
Q141K ++ ++ 0.0-35.5 421 5 C A 1, 2, 4, 5, 6, 7, 8
T153M ++ ++ 3.3 458 5 C T 5
R160Q N.D. N.D. 0.5 479 5 G A 8
Q166E ++ ++ N.D. 496 5 C G NCBI dbSNP rs1061017
I206L ++ ++ 10.0 616 6 A C 2
★★ F208S - - N.D. 623 6 T C NCBI dbSNP rs1061018
★★ S248P - - N.D. 742 7 T C NCBI dbSNP rs3116448
★★ E334stop - - N.D. 1000 9 G T NCBI dbSNP rs3201997
F431L ++ - 0.8 1291 11 T C 3
★★ S441N - - 0.5 1322 11 G A 7
F489L + - 0.5-0.8 1465 12 T C 3, 7
F571L ++ ++ 0.5 1711 14 T A NCBI dbSNP rs9282571
(★★) R575stop N.D. N.D. 0.5 1723 14 C T 8
N590Y ++ ++ 0.0-1.0 1768 15 A T 2, 5
D620N ++ ++ 0.5 1858 16 G A 8
  • Hemato, hematoporphyrin; NCBI, National Center for Biotechnology Information; N.D., not determined; ★, risk of porphyria; (★), potential risk is assumed as the lack of transport activity being as a result of a truncated protein.

  • a Genetic data were acquired from the following references: 1, Imai et al. (2002); 2, Zamber et al. (2003); 3, Itoda et al. (2003); 4. Backstrom et al. (2003); 5, Mizuarai et al. (2004); 6, de Jong et al. (2004); 7, Kobayashi et al. (2005); and 8, Bosch et al. (2005).