Linked to the FAAH gene. It is shown to be associated with drug abuse, and an increased risk for substance use disorders.

The A allele is associated with:

  • Early onset and adult obesity [R].
  • Anorexia nervosa and bulimia nervosa [R].
  • Lower HDL (high-density lipoprotein) levels [R]. 
  • Greater blood lipid reduction on a low fat diet [R].
  • Antipsychotic-induced weight gain (greatest in heterozygous AC genotype) [R, R].

The C allele is associated with:

  • Favourable response to cannabinoids in people with IBS [R].
  • Better response to a high monounsaturated fat hypocaloric diet [R].
  • Increased reward response to cannabinoids [R].


Parent Gene: FAAH

Importance: 2
Less common allele: A = 26%
More common allele: C = 74%
My Genotype: Log In
Risk Allele: A
Significance: risk factor