Balakrishnan Premalatha, Ramesh V, Balamurali P D, Kennedy Babu S P K, Prasad Karthiksree V, Gandhimadhi D
Department of Oral Pathology and Microbiology, Mahatma Gandhi Postgraduate Institute of Dental Science, Puducherry, India.
Department of Periodontics , Mahatma Gandhi Postgraduate Institute of Dental Science, Puducherry, India.
J Oral Maxillofac Pathol. 2020 Sep-Dec;24(3):505-509. doi: 10.4103/jomfp.JOMFP_273_18. Epub 2021 Jan 9.
Phenytoin-induced gingival overgrowth is an adverse drug reaction affecting few individuals, on phenytoin therapy for its antiepileptic effect. Analysis of genetic variation of CYP2C9*2 gene was done to identify the action of metabolic enzyme cytochrome P 450 on this drug. The main background of this publication is a quick review about one of the molecular techniques used to identify the single-nucleotide polymorphism (SNP) using polymerase chain reaction coupled with restriction fragment length polymorphism (PCR-RFLP).
Deoxyribonucleic acid (DNA) was extracted from 5 ml of venous blood withdrawn from the individual, who had gingival overgrowth following phenytoin therapy. DNA was isolated, using the phenol-chloroform method. Isolated DNA was used for SNP analysis of CYP2C9*2 presentation. The basic procedure used for SNP analysis in our case was PCR-RFLP.
Genetic variation of CYP2C9*2 in our case was homomutant.
The etiology of phenytoin-induced gingival overgrowth is always an enigma, but it is now becoming clearer that a multifactorial role may be involved in the cause. One of the factors analyzed was polymorphism of CYP2C9*2 gene and it was found to be homomutant in our case. Adverse drug reaction can be minimized, by either reducing the drug dosage or drug substitution. However, larger scale genome-wide study has to be carried out to confirm one of the etiopathogenesis as mutation of the CYP2C9 gene, in phenytoin-induced gingival overgrowth.
苯妥英钠所致牙龈增生是一种不良药物反应，仅少数接受苯妥英钠抗癫痫治疗的个体出现。对CYP2C9*2基因的遗传变异进行分析，以确定代谢酶细胞色素P450对该药物的作用。本出版物的主要背景是对一种分子技术的快速回顾，该技术使用聚合酶链反应结合限制性片段长度多态性（PCR-RFLP）来鉴定单核苷酸多态性（SNP）。
从接受苯妥英钠治疗后出现牙龈增生的个体抽取的5ml静脉血中提取脱氧核糖核酸（DNA）。采用酚-氯仿法分离DNA。分离得到的DNA用于CYP2C9*2表现型的SNP分析。我们病例中用于SNP分析的基本程序是PCR-RFLP。
我们病例中CYP2C9*2的遗传变异为纯合突变。
苯妥英钠所致牙龈增生的病因一直是个谜，但现在越来越清楚的是，其病因可能涉及多因素作用。所分析的因素之一是CYP2C9*2基因多态性，在我们的病例中发现为纯合突变。通过减少药物剂量或更换药物，可将药物不良反应降至最低。然而，必须开展更大规模的全基因组研究，以确认CYP2C9基因突变是否为苯妥英钠所致牙龈增生的发病机制之一。
