Brief Answer:
I have briefly mentioned the functionalities of the genes

Detailed Answer:
Thanks for asking on HealthcareMagic.

Methylation defects relate to activation of the genes. While the effects are severer in homozygous conditions, the functionalities might be partly affected in heterozygous condition. Each gene in our body has a specific role to play. However, in spite of the vast extension of our knowledge into this field, our understanding of the functionalities of all the genes is still limited. I am listing some of the known functionalities of the mentioned genes:
* VDR Bsm I or vitamin D receptor gene (VDR), might be associated with susceptibility to colorectal cancer in addition to problems in calcium metabolism.
* MAO-A R297R defects result in the bodies inability to produce the MAO-A enzyme, or Monoamine Oxidase Type A enzyme. This enzyme is partially responsbile for breaking down norepinephrine (noradrenaline), epinephrine (adrenaline), serotonin, and dopamine.
* BHMT-02 and BHMT-08 are related to betaine homocysteine methyltransferase which acts as a shortcut through the methylation cycle helping convert homocysteine to methionine. The activity of the enzyme can be negatively influenced by stress and methylation defects in these genes affect this function.
* MTHFR C677T relates to Methylenetetrahydrofolate reductase (MTHFR), a very important enzymes in human physiology which has influence on many biochemical processes but is mostly known in the context of breaking down the amino acid homocysteine. Impaired MTHFR function has multiple negative impacts on DNA synthesis and repair, embryonic development, neurotransmitter synthesis, and cardiovascular risk factors.
* MTRR K350A relates to 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR). This enzyme is required for the proper function of another enzyme called methionine synthase. Without methionine synthase reductase, methionine synthase cannot convert homocysteine to methionine. As a result, homocysteine builds up in the bloodstream, and the amount of methionine is reduced. Altered levels of homocysteine and methionine lead to the health problems associated with homocystinuria.

I could write a few pages on each of these but I am sure that is not what you need. I had therefore skipped the technicalities last time when you had asked the question.

Let me know if you have further queries and I would be happy to resolve them.

Regards

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Brief Answer:
Disease correlation is not present for each possible variation in a gene

Detailed Answer:
Thanks for writing back.

Single nucleotide polymorphisms, frequently called SNPs (pronounced 'snips'), are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide. For a particular gene which is composed of a vast number of nucleotides distributed over one or more locii (plural of locus), SNPs can occur at number of locations and a number of genotypic variations are possible. But sometimes SNPs occurs without corresponding to any definite genotype. In such a case, it is mentioned as 'no call', meaning that there is no exact match found in the genotype database. In other words, a 'no call' indicates that the data produced during the assay testing was insufficient to reliably link the condition to some specific genotypic presentation and it cannot be commented upon whether it has any actual significance attached.

The following link may be helpful in this regard:
https://yyyyyyyyyyyyyy.23andme.com/hc/en-us/yyyyyyyyyyyy/0000-yyyyyy-does-No-call-Not-yyyyyyyyyyy-yyyyyyyy-in-yyyyyyyyyy-yyyyy-yyyyyyyy-

Telomeres are segments attached to ends of genes. Short is good.

Regards

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