背景:Alpe-DPD研究(NCT02324452)表明,在DPYD中使用四个等位基因进行前瞻性基因分型和剂量个体化(DPYD*2A/rs3918290,c.1236G>A/rs75017182,c.2846A>T/rs67376798和c.1679T>rs56060477可以减轻氟然而,这不能阻止所有的毒性。这项研究的目的是确定额外的遗传变异,DPYD内外,这可能有助于氟嘧啶的毒性。
方法:使用来自Alpe-DPD研究的生物样本和数据。进行外显子测序以鉴定DPYD内部的风险变体。使用计算机模拟和体外分析对DPYD变体进行分类。进行了具有严重氟嘧啶相关毒性的全基因组关联研究(GWAS),以鉴定DPYD以外的变体。使用配对分析的外显子测序和逻辑分析评估了与严重毒性的关联,考克斯,和GWAS的序数回归分析。
结果:二十四个非同义词,移码,在986例患者中有10例检测到剪接位点DPYD变异。这些变体中的七个(c.1670C>T,c.1913T>C,c.1925T>C,c.506delC,c.731A>C,c.1740+1G>T,c.763-2A>G)被预测为有害的。与匹配的对照(N=30)相比,这些变体的携带者显示出严重毒性风险增加2.14倍(95%CI,0.41-11.3,P=0.388)的趋势。在942名患者的GWAS之后,没有个体单核苷酸多态性达到全基因组意义(P≤5×10-8),然而,5个变异提示与严重毒性相关(P<5×10-6).
结论:来自DPYD外显子测序和GWAS分析的结果未发现与严重毒性相关的其他遗传变异,这表明在人群水平上对单一标志物的检测目前具有有限的临床价值。在个体水平上识别其他变体仍然有希望解释氟嘧啶相关的严重毒性。此外,样本量较大的研究,在更多样化的队列中,需要确定与氟嘧啶严重毒性相关的潜在临床相关遗传变异.
BACKGROUND: The Alpe-DPD study (NCT02324452) demonstrated that prospective genotyping and dose-individualization using four alleles in DPYD (DPYD*2A/rs3918290, c.1236G > A/rs75017182, c.2846A > T/rs67376798 and c.1679 T > G/rs56038477) can mitigate the risk of severe fluoropyrimidine toxicity. However, this could not prevent all toxicities. The goal of this study was to identify additional genetic variants, both inside and outside DPYD, that may contribute to fluoropyrimidine toxicity.
METHODS: Biospecimens and data from the Alpe-DPD study were used. Exon sequencing was performed to identify risk variants inside DPYD. In silico and in vitro analyses were used to classify DPYD variants. A genome-wide association study (GWAS) with severe fluoropyrimidine-related toxicity was performed to identify variants outside DPYD. Association with severe toxicity was assessed using matched-pair analyses for the exon sequencing and logistic, Cox, and ordinal regression analyses for GWAS.
RESULTS: Twenty-four non-synonymous, frameshift, and splice site DPYD variants were detected in ten of 986 patients. Seven of these variants (c.1670C > T, c.1913 T > C, c.1925 T > C, c.506delC, c.731A > C, c.1740 + 1G > T, c.763 - 2A > G) were predicted to be deleterious. The carriers of either of these variants showed a trend towards a 2.14-fold (95% CI, 0.41-11.3, P = 0.388) increased risk of severe toxicity compared to matched controls (N = 30). After GWAS of 942 patients, no individual single nucleotide polymorphisms achieved genome-wide significance (P ≤ 5 × 10-8), however, five variants were suggestive of association (P < 5 × 10-6) with severe toxicity.
CONCLUSIONS: Results from DPYD exon sequencing and GWAS analysis did not identify additional genetic variants associated with severe toxicity, which suggests that testing for single markers at a population level currently has limited clinical value. Identifying additional variants on an individual level is still promising to explain fluoropyrimidine-related severe toxicity. In addition, studies with larger samples sizes, in more diverse cohorts are needed to identify potential clinically relevant genetic variants related to severe fluoropyrimidine toxicity.