Feng, Xiaodong_ Xie, Hong-Guang - Applying pharmacogenomics in therapeutics-CRC Press (2016)

Pharmacogenomics and Alternative Medicine
251
and pregnancy). Folic acid can promote immature cells in the bone marrow to form
morphologically normal red blood cells, thus avoiding anemia.
Meta-analysis has shown that the 677T/T genotype in the gene MTHFR encoding
methylenetetrahydrofolate reductase (MTHFR) was associated with 14–21% higher
risk of developing cardiovascular diseases compared with carriage of 677 C allele. 15
Maria et al. have found that folic acid interacts with MTHFR 677C/T polymorphism,
affecting the incidence of colorectal cancer (p = 0.037): if folic acid level is low and
with MTHFR 677T/T genotype, patients would be at higher risk for colorectal cancer
(OR = 2.4), indicating that the body’s folic acid levels are more important for patients
with the MTHFR 677T/T genotype. 16
Reduced folate carrier (RFC-1, encoded by the gene SLC19A1) is a folic acid
transporter in vivo, and it is involved in folic acid transport across the placenta,
blood–brain barrier, renal, and other physiological processes. Folic acid deficiency
can cause intracellular DNA methylation abnormalities, ultimately leading to congenital
diseases, cancer, cardiovascular diseases, and neuropsychiatric diseases.
RFC-1 gene 80A/G polymorphism and increased plasma homocysteine levels are
associated with decreased folic acid levels, likely causing congenital disorders.
A meta-analysis involving 930 mothers of Down syndrome (DS) children and 1240
mothers of normal controls has shown that RFC-1 gene 80G/G genotype has a 1.27-
fold higher risk of DS. The single G allele is associated with a 1.14-fold increased
risk of DS. 17 This result shows that RFC-1 gene polymorphism can affect the neural
system development of the fetus by regulating the transportation of folic acid
in vivo.
MINERALS AND TRACE ELEMENTS
Minerals are a general name for a variety of elements that constitute human tissues
and maintain normal physiological functions. Minerals are also essential nutrients
for the human body. Carbon, oxygen, hydrogen, nitrogen, and other elements are
mainly in the form of organics, and the remaining 60 elements are often referred to
as minerals (inorganics) in the human body.
Calcium, magnesium, potassium, sodium, phosphorus, sulfur, and chlorine
account for approximately 60–80% of total minerals in the body. Therefore, these
seven elements are called macroelements. Iron, copper, iodine, zinc, selenium, manganese,
molybdenum, cobalt, chromium, tin, vanadium, silicon, nickel, and fluorine
account for less than 0.005% of total minerals in the body; therefore, these 14 elements
are called microelements or trace elements. Although minerals cannot provide
energy, they play an important role in human physiology. Human bodies are
unable to synthesize these minerals and must get them from the outside environment.
Minerals are the staples that make up the organs and tissues. For example, calcium,
phosphorus, and magnesium are the main ingredients of bones and teeth. Minerals
are also necessary for normal osmotic pressure and acid–base balance of the body.
Synthesis of some specific biological molecules, such as hemoglobin and thyroid
hormone, requires iodine. The interactions between human gene polymorphism and
minerals/trace elements may affect the normal physiological functions of the human
body and the occurrence of diseases.