SNP rs6564851 in the BCO1 Gene Is Associated with Varying Provitamin a Plasma Concentrations but Not with Retinol Concentrations among Adolescents from Rural Ghana

Abstract

In sub-Saharan Africa, vitamin A deficiency constitutes a severe health problem despite various supplementation and food fortification programs. Given that the intake of preformed vitamin A from animal products remains low in these countries, an efficient metabolization of plant-based provitamin A carotenoids is essential. Previously, adolescents in rural Ghana have shown high total plasma carotenoid concentrations, while 36% had a vitamin A deficiency (defined as plasma retinol < 0.7 µmol/L). Hence, the aim of this cross-sectional study was to identify the relationships between variants in the β-carotene 15,15’-oxygenase (BCO1) gene and plasma carotenoid concentrations among 189 15-year-old girls and boys in rural Ghana. BCO1 rs6564851, rs7500996, rs10048138 and PKD1L2 rs6420424, and rs8044334 were typed, and carotenoid concentrations were compared among the different genotypes. G allele carriers of rs6564851 (53%) showed higher plasma carotenoid concentrations than T allele carriers (median (interquartile range): 3.07 (2.17–4.02) vs. 2.59 (2.21–3.50) µmol/L, p-value = 0.0424). This was not explained by differences in socio-demographic or dietary factors. In contrast, no differences in plasma retinol concentrations were observed between these genotypes. Pending verification in independent populations, the low conversion efficiency of provitamin A carotenoids among rs6564851 G allele carriers may undermine existing fortification and supplementation programs to improve the vitamin A status in sub-Saharan Africa.

Whole Genome Interpretation for a Family of Five

“…An example of nutrition marker we classify as possible is BCO1 (rs6564851). According to our research ( Table 4 ), there are 4 studies with a number of total subjects analyzed of 328 (Yabuta et al, 2016 ; Moran et al, 2019 ; Amengual et al, 2020 ; Graßmann et al, 2020 ). Our judgement of the underlying knowledge of the biological mechanism involved is medium and there are some cases where a potential intervention may not have the desired effect.…”

“…Each additional copy of the rs9939609 A allele has been associated with a BMI increase of a mean of 0.10 Z -score units, equivalent to ~0.4 kg/m 2 (Sonestedt et al, 2009 ; Tanofsky-Kraff et al, 2009 ; Zhao et al, 2014b ). For the observed genotypes in APOA2 and FADS1 , there is no associated effect (Yabuta et al, 2016 ; Huang et al, 2017 ; Ching et al, 2019 ; Moran et al, 2019 ; Amengual et al, 2020 ; Graßmann et al, 2020 ; Wang et al, 2020 ). For LEPR , a study found that rs1137101 AG and GG carriers with a high fat total intake had 3.0 times higher risk of obesity and 4.1 times higher risk of high cholesterol levels than those with a low intake of total fat (Domínguez-Reyes et al, 2015 ).…”

Genetic Variations of Vitamin A-Absorption and Storage-Related Genes, and Their Potential Contribution to Vitamin A Deficiency Risks Among Different Ethnic Groups

“…The associations between other common variants of the gene and genes adjacent to the BCO1 gene and serum β-carotene status also have been extensively reported ( 40 – 45 ). The rs6564851 common variant located about 8 kb upstream of the BCO1 gene is reported to be associated with circulating levels of β-carotene in different ethnic groups ( 40 , 43 , 44 ). The rs6564851 variant is located within a haplotype that includes other genetic polymorphisms ( Figure 1A ).…”