N-acetylation phenotyping using dapsone in a Jordanian population.

Area of Science:

• Pharmacogenomics
• Drug Metabolism
• Human Genetics

Background:

• Dapsone (DDS) is a crucial drug with variable patient responses.
• N-acetylation is a key metabolic pathway influencing DDS efficacy and toxicity.
• Genetic variations in acetylator enzymes impact drug pharmacokinetics.

Purpose of the Study:

• To determine the frequency of slow N-acetylation phenotype in a Jordanian population.
• To investigate the genetic basis of dapsone acetylation using the Hardy-Weinberg Law.
• To correlate plasma concentrations of dapsone and its metabolite with acetylation status.

Main Methods:

• Studied N-acetylation of dapsone (DDS) in 160 healthy Jordanian volunteers.
• Determined slow acetylator phenotype using the plasma monoacetyldapsone (MADDS) to DDS ratio (MADDS/DDS).
• Applied Hardy-Weinberg Law to estimate allele frequencies and compared observed vs. predicted genotype counts.

Main Results:

• A high frequency of slow acetylators (67.5%) was observed, with an acetylation ratio < 0.42.
• The frequency of the slow acetylation allele was calculated as 0.82 +/- 0.02.
• Significant correlation found between plasma MADDS concentration and acetylation ratio (r=0.853), but not for DDS.

Conclusions:

• The Jordanian population exhibits a high prevalence of the slow acetylator phenotype for dapsone.
• Observed genotype frequencies deviated from Hardy-Weinberg predictions, suggesting potential complexities in the genetic model.
• Findings highlight the importance of pharmacogenetic considerations in dapsone therapy within this population.