Examples of Pharmacogenetic Variations

Variation

Incidence

Examples of Effects

Acetylation, fast

Acetylation, slow (drug inactivation by hepatic N-acetyltransferase)

About 50% of the US population

Aldehyde dehydrogenase-2 deficiency

About 50% of Japanese, Chinese, and other Asian populations

With alcohol ingestion, marked elevations of blood acetaldehyde, causing facial flushing, increased heart rate, diaphoresis, muscle weakness, and sometimes catecholamine-mediated vasodilation with euphoria

CYP2C9 genetic polymorphisms

30% in one study

More common among East Asians

thrombosis in high-risk patients

G6PD deficiency

10% of males of African descent

Higher prevalence in people of Mediterranean descent

hemolytic anemia

Genetic polymorphisms of CYP2C9 and vitamin K epoxide reductase complex subunit 1 (VKORC1)

About 50% of a given population carries at least 1 allele

HLA-B*1502

1 to 6/10,000 in countries with mainly white populations

In some Asian countries, about 10 times higher

Stevens-Johnson syndrome)

Plasma pseudocholinesterase deficiency

About 1/1500 people

* In one study, variations in CYP2C9 or VKORC1

In these topics