Vitamin B6 (ALPL)
ALPL · rs4654748
Pyridoxal-5′-phosphate (PLP) is an active form of vitamin B6 involved in many enzyme reactions. Variants near ALPL have been associated with differences in measured PLP levels. These markers neither measure B6 status nor establish a deficiency.
Key points
- The ALPL locus on chromosome 1p36 is genome-wide significant for the PLP level.
- The effect allele goes along with lower B6 levels, likely via altered hydrolysis of the coenzyme.
- B6 is essential for neurotransmitter synthesis and homocysteine breakdown.
The markers
Alkaline phosphatase (ALPL) can hydrolyse PLP. A genome-wide meta-analysis associated a region near ALPL with plasma PLP; rs4654748 marked this association (Hazra 2009). A statistical marker at this locus does not reveal a person's current B6 level.
What it means
These SNPs replace neither laboratory measurements nor clinical assessment. Even considering the links with folate and B12 metabolism, the markers alone do not establish an individual's nutrient needs.
Context
The studied markers describe associations with group-level measurements. Genome displays them as technical variant information; they cannot establish whether someone has a deficiency.
What Genome measures. The genotypes at rs4654748 (near ALPL) and the adjacent rs1256335 (NBPF3).
Related topics
Sources
- 1Hazra et al., 2009 Genome-wide significant predictors of metabolites in the one-carbon metabolism pathway. Human Molecular Genetics 18:4677-4687. doi.org/10.1093/hmg/ddp428