Table 4.

Overview of genetic association studies related to umami taste preferences.

Gene	SNP	Applied tastant/method	Number of studies with confirmed association	Findings	Reference	Number of studies with no association	Reference
TAS1R3	rs307377	Umami	3	Significant associations between allele frequency and recognition threshold for IMP. The mutation was less frequent in tasters than expected. CT subjects rated MPG/L twice as did those with CC genotype.	(Shigemura et al., 2009; Raliou et al., 2009; Chen et al., 2009)	0	–
TAS1R3	rs76755863	Umami	2	The mutation G13A was associated with non-tasters and hypotasters. For the rare allele doubling of umami taste intensity ratings.	(Raliou et al., 2009; Chen et al., 2009)	0	–
TAS1R3	rs111615792	Umami	1	For the rare allele doubling of umami taste intensity ratings.	(Chen et al., 2009)	0	–
TAS1R1	rs34160967	Umami	1	Significant associations between genotypes and recognition thresholds for MSG and M+I. The SNP was more frequent in tasters than expected.	(Shigemura et al., 2009; Raliou et al., 2009)	2	(Chen et al., 2009; Risso et al., 2017)
TAS1R1	rs41278020	Umami	1	The mutation was more frequent in non-tasters than expected.	(Raliou et al., 2009)	1	(Chen et al., 2009)
TAS1R1	rs35118458	Umami	1	The mutation tended to be more frequent in non-tasters.	(Raliou et al., 2009)	0	–
GRM1	rs2814863	Umami	1	The mutation tended to be associated with the non-taster phenotype.	(Raliou et al., 2009)	0	–

For SNPs with more than one confirmed association are presented in bold.

IMP, inosine monophosphate; MPG, monopotassium glutamate; MSG, monosodium glutamate; M+I: MSG in the presence of IMP.