Genetic Variations and Haplotype Diversity of the UGT1 Gene Cluster in the Chinese Population

Vertebrates require tremendous molecular diversity to defend against numerous small hydrophobic chemicals. UDP-glucuronosyltransferases (UGTs) are a large family of detoxification enzymes that glucuronidate xenobiotics and endobiotics, facilitating their excretion from the body. The UGT1 gene cluster contains a tandem array of variable first exons, each preceded by a specific promoter, and a common set of downstream constant exons, similar to the genomic organization of the protocadherin (Pcdh), immunoglobulin, and T-cell receptor gene clusters. To assist pharmacogenomics studies in Chinese, we sequenced nine first exons, promoter and intronic regions, and five common exons of the UGT1 gene cluster in a population sample of 253 unrelated Chinese individuals. We identified 101 polymorphisms and found 15 novel SNPs. We then computed allele frequencies for each polymorphism and reconstructed their linkage disequilibrium (LD) map. The UGT1 cluster can be divided into five linkage blocks: Block 9 (UGT1A9), Block 9/7/6 (UGT1A9, UGT1A7, and UGT1A6), Block 5 (UGT1A5), Block 4/3 (UGT1A4 and UGT1A3), and Block 3′ UTR. Furthermore, we inferred haplotypes and selected their tagSNPs. Finally, comparing our data with those of three other populations of the HapMap project revealed ethnic specificity of the UGT1 genetic diversity in Chinese. These findings have important implications for future molecular genetic studies of the UGT1 gene cluster as well as for personalized medical therapies in Chinese

Worsening of Asthma with Systemic Corticosteroids: A Case Report and Review of Literature

Despite widespread use for treatment of asthma and allergies, glucocorticoids may cause allergic reactions, even anaphylaxis. The incidence of adverse reactions to systemic glucocorticoids is 0.3%. The most commonly reported corticosteroids causing anaphylaxis like reactions are hydrocortisone, prednisone, and methylprednisolone. Most authors agree that allergic reactions to systemic corticosteroids are possibly immunoglobulin E mediated. We report a patient with asthma, aspirin allergy, and nasal polyps who developed bronchospasm following the administration of intravenous methylprednisolone sodium succinate during an acute asthmatic attack. We discuss the differential diagnosis of worsening asthma despite adequate treatment, and suggest corticosteroid-induced bronchospasm in our patient. Corticosteroid-induced bronchospasm should be considered when asthmatics fail to improve, or frankly deteriorate with systemic corticosteroid therapy, particularly when a history of aspirin allergy is present. Teaching Point Know the differential diagnosis for worsening of asthma despite adequate treatment. Consider corticosteroid-induced bronchospasm when asthmatics fail to improve, or frankly deteriorate with systemic corticosteroid therapy. Corticosteroid-induced bronchospasm is more commonly seen in asthmatics with a history of aspirin allergy