Related Experiment Video
Updated: Jun 8, 2025

Author Spotlight: Genetic Profiling for Fluorouracil Response in Gastric Cancer
Published on: May 10, 2024
Relationship between SLCO1B1 polymorphisms and methotrexate intolerance in Mexican children with juvenile idiopathic
Jimena Garcia-Silva1, Beatriz Silva-Ramirez2, Ana V Villarreal-Treviño1
1Departamento de Pediatría, Hospital Universitario "José Eleuterio González", Universidad Autónoma de Nuevo León, Av. Francisco I. Madero Pte. y Av. Gonzalitos, Col. Mitras Centro C.P., 64460, Monterrey, NL, Mexico.
Introduction:
The most frequent adverse events (AEs) of methotrexate (MTX) are gastrointestinal symptoms and hepatotoxicity, which can affect its adherence, leading to reduced effectiveness. The SLCO1B1 gene codes for a liver protein (OATP1B1) responsible for drug transportation. Genetic variations within the SLCO1B1 gene locus impact drug transport, leading to altered pharmacokinetic profiles, delayed MTX clearance, and increased risk of toxicity. This study aimed to determine the association between single nucleotide polymorphisms (SNPs) in the SLCO1B1 gene (rs4149056, rs2306283) with the development of AEs in patients with juvenile idiopathic arthritis (JIA) treated with MTX.
Method:
We performed an observational retrospective study to analyze the relationship between SNPs in the SLCO1B1 gene and the development of AEs in pediatric patients treated with MTX for JIA.
Results:
Thirty patients with JIA were included, 22 females (73.3%), with a median age of 11 years (IQR 8.3-15). The most frequent JIA subtype was rheumatoid factor-positive polyarthritis (36.7%). Twenty patients (66.7%) reported AEs. The *1B haplotype was the most frequent in this group (53.3%) and conferred a higher risk of developing AEs (OR = 3.89, 95% CI = 1.23 -12.29, p = 0.03).
Conclusions:
Patients with the allele *1B may benefit from lower doses of MTX. SLCO1B1 genotyping is a promising technique to identify patients at higher risk of AEs during treatment with MTX, thus requiring dose optimization.
More Related Videos
Related Concept Videos
Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents
Translation
Translation Produces the Building Blocks of Life
Proteins are...
Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
Drugs for Treatment of Ulcerative Colitis in IBD
Non-LTR Retrotransposons
Phase II Reactions: Methylation Reactions
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...

