Common Terminology

 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.  To be classified as a SNP, two or more versions of a sequence must each be present in at least one percent of the general population.

Genes are chunks of DNA that contribute to particular traits or functions by coding for proteins that influence physiology. 

Alleles are different versions of a gene, which vary according to the nucleotide base present at a particular genome location. 

Most disease-causing mutations occur within a gene's coding or regulatory regions and affect the function of the protein encoded by the gene.   These are known as Causative SNPs since they affect the way a protein functions. 

Genes are inherited from your parents and they are responsible for features being passed down from one generation to the next. Someone's genotype consists of their entire set of genes. Every person has a unique genotype, which explains the vast differences in human appearance and biology. 

Every person has two copies, or alleles, of a single gene. When the alleles are the same, they are known as homozygous.  A homozygous mutation means both allele copies are mutated.  This can have a more significant impact on a person due to both alleles being mutated. 

Every person has two copies, or alleles, of a single gene. When the alleles are different, they are known as heterozygous. A heterozygous mutation means there's only one copy of the mutated allele. 

The MTHFR gene provides instructions for making an enzyme called   methylenetetrahydrofolate reductase. This enzyme plays a role in processing amino acids and is important for a chemical reaction involving folate (vitamin B9) and is necessary to convert homocysteine to methionine. A polymorphism of this gene can lead to decreased production of certain neurotransmitters such as serotonin and catecholamines (dopamine & adrenaline).  

An increase in homocysteine levels caused by MTHFR gene polymorphisms has been studied as a possible risk factor for cancer, dementia, Alzeheimer's, stroke, miscarriages, anxiety, ADHD, chronic fatigue, depression, migraines, neural tube defects, migraines and many other conditions.  For this reason it is highly recommended to check your homocysteine level regularly. This can be easily added as part of routine bloodwork. 

 The COMT gene provides instructions for making an enzyme called catechol-O-methyltransferase.  This enzyme is responsible for breaking down certain neurotransmitters. It is especially important in the prefrontal cortex, which is involved with personality, planning, inhibition, emotion and short term memory. The prefrontal cortex requires neurotransmitters such as dopamine and norepinephrine and COMT helps regulate these. Mutations of this gene can lead to increased risk of depression, anxiety, OCD, ADHD and many other conditions.

 The VDR gene provides instructions for making a protein called vitamin D receptor (VDR), which allows the body to respond to vitamin D.  This gene supports brain health by increasing dopamine production.  Among other health issues, VDR polymorphisms have been associated with the risk of developing Parkinson's disease due to low dopamine levels. 

CBS catalyzes the first step of the transsulfuration pathway, from homocysteine to cystathionine. Mutations are usually an upregulation of the enzyme, meaning it works too fast. Rapid conversion of homocysteine and cystathionine to taurine can lead to high levels of taurine and ammonia.  This can lead to sulfur intolerance in some people. It can also lead to low levels of BH4 which helps regulate neurotransmitters and mood. It may help to avoid high doses of sulfur from supplements like taurine, glutathione, lipoic acid and foods like garlic, eggs and cruciferous vegetables.