1. |
- Perera, Minoli A., et al.
(author)
-
Genetic variants associated with warfarin dose in African-American individuals : a genome-wide association study
- 2013
-
In: The Lancet. - 0140-6736 .- 1474-547X. ; 382:9894, s. 790-796
-
Journal article (peer-reviewed)abstract
- Background VKORC1 and CYP2C9 are important contributors to warfarin dose variability, but explain less variability for individuals of African descent than for those of European or Asian descent. We aimed to identify additional variants contributing to warfarin dose requirements in African Americans. Methods We did a genome-wide association study of discovery and replication cohorts. Samples from African-American adults (aged >= 18 years) who were taking a stable maintenance dose of warfarin were obtained at International Warfarin Pharmacogenetics Consortium (IWPC) sites and the University of Alabama at Birmingham (Birmingham, AL, USA). Patients enrolled at IWPC sites but who were not used for discovery made up the independent replication cohort. All participants were genotyped. We did a stepwise conditional analysis, conditioning first for VKORC1 -1639G -> A, followed by the composite genotype of CYP2C9*2 and CYP2C9*3. We prespecified a genome-wide significance threshold of p<5x10(-8) in the discovery cohort and p<0.0038 in the replication cohort. Findings The discovery cohort contained 533 participants and the replication cohort 432 participants. After the prespecified conditioning in the discovery cohort, we identified an association between a novel single nucleotide polymorphism in the CYP2C cluster on chromosome 10 (rs12777823) and warfarin dose requirement that reached genome-wide significance (p=1.51x10(-8)). This association was confirmed in the replication cohort (p=5.04x10(-5)); analysis of the two cohorts together produced a p value of 4.5x10(-12). Individuals heterozygous for the rs12777823 A allele need a dose reduction of 6.92 mg/week and those homozygous 9.34 mg/week. Regression analysis showed that the inclusion of rs12777823 significantly improves warfarin dose variability explained by the IWPC dosing algorithm (21% relative improvement). Interpretation A novel CYP2C single nucleotide polymorphism exerts a clinically relevant effect on warfarin dose in African Americans, independent of CYP2C9*2 and CYP2C9*3. Incorporation of this variant into pharmacogenetic dosing algorithms could improve warfarin dose prediction in this population.
|
|
2. |
- Desnick, Robert J., et al.
(author)
-
Roscoe Owen Brady, MD : Remembrances of co-investigators and colleagues
- 2017
-
In: Molecular Genetics and Metabolism. - : Elsevier BV. - 1096-7192. ; 120:1-2, s. 1-7
-
Journal article (peer-reviewed)abstract
- To celebrate the research visions and accomplishments of the late Roscoe O. Brady (1923-2016), remembrance commentaries were requested from several of his postdoctoral research fellows and colleagues. These commentaries not only reflect on the accomplishments of Dr. Brady, but they also share some of the backstories and experiences working in the Brady laboratory. They provide insights and perspectives on Brady's research activities, and especially on his efforts to develop an effective treatment for patients with Type 1 Gaucher disease. These remembrances illuminate Brady's efforts to implement the latest scientific advances with an outstanding team of young co-investigators to develop and demonstrate the safety and effectiveness of the first enzyme replacement therapy for a lysosomal storage disease. Brady's pursuit and persistence in accomplishing his research objectives provide insights into this remarkably successful physician scientist who paved the way for the development of treatments for patients with other lysosomal storage diseases.
|
|
3. |
- Bergdahl, Ingvar A., et al.
(author)
-
Lead binding to delta-aminolevulinic acid dehydratase (ALAD) in human erythrocytes
- 1997
-
In: Basic and Clinical Pharmacology and Toxicology. - : Wiley. - 0901-9928. ; 81:4, s. 153-158
-
Journal article (peer-reviewed)abstract
- Over 99% of the lead present in blood is usually found in erythrocytes. To investigate the nature of this selective accumulation of lead in erythrocytes, the specific binding of lead to proteins in human erythrocytes was studied using liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS). The principal lead-binding protein had a mass of approximately 240 kDa, and adsorption to specific antibodies showed that protein was delta-aminolevulinic acid dehydratase (ALAD). Thus, the previous notion that lead in erythrocytes was bound primarily to haemoglobin has to be revised. Furthermore, in lead-exposed workers, the percentage of lead bound to ALAD was influenced by a common polymorphism in the ALAD gene. Specifically, in seven carriers of the ALAD2 allele, 84% of the protein-bound lead recovered was bound to ALAD compared to 81% in seven homozygotes for the ALAD1 allele whose erythrocytes were matched for blood-lead concentration. The small difference was statistically significant in Wilcoxon matched-pairs signed-rank test (P = 0.03). No ALAD allele-specific difference in ALAD-bound lead was found among 20 unexposed controls. Perhaps the difference in ALAD-bound lead can provide an explanation for the previously reported finding of higher blood-lead levels among carriers of the ALAD2 allele than among ALAD1 homozygotes in lead-exposed populations.
|
|