ADH1B

ADH1B

ADH1B (Alcohol Dehydrogenase 1B) is a gene that encodes an enzyme belonging to the alcohol dehydrogenase family. This enzyme is primarily involved in the metabolism of alcohols in the liver, converting ethanol to acetaldehyde, a process that is crucial in the metabolism of alcoholic beverages. Variations in the ADH1B gene can significantly affect an individual's alcohol metabolism and susceptibility to alcohol-related diseases.

Function

The ADH1B gene is located on chromosome 4q23 and encodes the beta subunit of the class I alcohol dehydrogenase enzyme. This enzyme is a homodimer, meaning it consists of two identical subunits, and it catalyzes the oxidation of alcohols to aldehydes. The reaction is as follows:

Ethanol + NAD⁺ → Acetaldehyde + NADH + H⁺

This reaction is the first step in the metabolic pathway of ethanol, which is further metabolized to acetate by aldehyde dehydrogenase.

Genetic Variants

There are several known polymorphisms of the ADH1B gene, with the most studied being the ADH1B*1 and ADH1B*2 alleles. The ADH1B*2 allele encodes a variant enzyme with a higher catalytic activity compared to the ADH1B*1 allele. This results in a faster conversion of ethanol to acetaldehyde, which can lead to the accumulation of acetaldehyde and cause unpleasant effects such as flushing, nausea, and tachycardia. This is often referred to as the "alcohol flush reaction."

Clinical Significance

The ADH1B*2 allele is more prevalent in East Asian populations and is associated with a reduced risk of alcoholism due to the aversive effects of acetaldehyde accumulation. Conversely, individuals with the ADH1B*1 allele may metabolize alcohol more slowly, potentially increasing the risk of alcohol dependence and related liver diseases.

Research and Implications

Research into ADH1B and its variants has implications for understanding the genetic basis of alcohol use disorders and developing personalized treatment strategies. Genetic testing for ADH1B variants can provide insights into an individual's risk for alcohol-related health issues and guide clinical decisions.

Also see

• Alcohol dehydrogenase
• Aldehyde dehydrogenase
• Ethanol metabolism
• Genetic polymorphism
• Alcohol use disorder