Transcobalamin receptor gene polymorphisms and mutation in an elderly population
Andrew McCaddon1, Daniel F Carr2, Hudson Peter3
1Faculty of Social and Life Sciences, Wrexham Glyndwr University, Wrexham, UK.
Clinical Nutrition ESPEN
|May 18, 2023
Summary
Genetic variations in the transcobalamin receptor (TCblR/CD320) influence vitamin B12 status. Specific CD320 haplotypes significantly alter holotranscobalamin levels in elderly individuals.
Area of Science:
- Biochemistry
- Genetics
- Nutritional Science
Background:
- Vitamin B12 (cobalamin) cellular uptake relies on the transcobalamin receptor (TCblR/CD320).
- Genetic variations (polymorphisms) in TCblR/CD320 are known, but their clinical impact on vitamin B12 status remains unclear.
Purpose of the Study:
- To investigate the association between CD320 genetic variants and vitamin B12 status markers.
- To determine the influence of TCblR/CD320 polymorphisms on holotranscobalamin (holo-TC) levels.
Main Methods:
- CD320 genotyping was performed on 377 elderly individuals.
- Analysis of identified polymorphisms and codon deletions in the exon 2 region of CD320.
Main Results:
- Three polymorphisms and a codon deletion in CD320 exon 2 were identified.
- Individuals with specific TCblR/CD320 haplotypes exhibited significantly higher holo-TC levels and a greater holo-TC to total cobalamin ratio.
- TCblR haplotype accounted for 46% of the variability observed in holo-TC values.
Conclusions:
- CD320 genetic variants significantly impact vitamin B12 status indicators, particularly holo-TC levels.
- The findings suggest that current models for assessing B12 status, relying on intracellular flux via the TC-Cbl receptor, may need adjustments to incorporate CD320 haplotype variations.
Related Concept Videos
01:31Translation
15.0K
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Proteins are...
Translation Produces the Building Blocks of Life
Proteins are...
15.0K
02:26Comparing Copy Number Variations and SNPs
17.8K
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
17.8K
01:05Single Nucleotide Polymorphisms-SNPs
15.3K
A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
15.3K
01:11Genome-wide Association Studies-GWAS
13.7K
Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
GWAS does not require the identification of the target gene involved in...
13.7K
02:28Leaky Scanning
5.2K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.2K