What are SNPs? Describe how a common SNP in a fat metabolism gene changes the body's response to dietary fats

Answer 1

The most common DNA mutations are SNPs, involving the variation of a single nucleotide in a strand of DNA. A single SNP in a high-powered gene can produce a severe disease immediately from birth, such as PKU. More commonly, SNPs do not cause a disease directly but may subtly work with other gene variants and with environmental factors such as diet to increase the risk of developing a chronic disease, such as heart disease, later in life. SNPs set the stage for a chronic disease but the person's own choices are among the actors that cause it to develop.
As an example, a common SNP in a fat metabolism gene changes the body's response to dietary fats. People with this SNP maintain lower blood LDL cholesterol when they eat a diet rich in polyunsaturated fatty acids (PUFA), and they develop higher blood LDL cholesterol when they consume less PUFA. A gene (in this case, a fat metabolism gene with a SNP) interacts with a nutrient from the diet (in this case, PUFA) to influence a risk factor for a disease (LDL cholesterol, implicated in heart disease).