Gene mutation type and clinical phenotype of patients with PRRT2 mutation and their relations with prognosis
10.3760/cma.j.cn115354-20240812-00481
- VernacularTitle:PRRT2基因突变患者的基因突变类型、临床表型及二者与患者预后的关系
- Author:
Yajing GAN
1
;
Jiewen DENG
;
Guoyan LI
;
Zihan WEI
;
Yan FENG
;
Yuqing SHI
;
Chuchu ZHANG
;
Yanchun DENG
Author Information
1. 空军军医大学第一附属医院神经内科，西安 710032
- Keywords:
PRRT2 gene;
Mutation type;
Clinical phenotype;
Prognosis
- From:
Chinese Journal of Neuromedicine
2024;23(9):895-902
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the gene mutation type and clinical phenotype of patients with PRRT2 mutation, and explore their relations with prognosis. Methods:A total of 18 patients with PRRT2 gene mutation (1 patient with novel mutation in PRRT2 gene, and 17 probands in 17 families with PRRT2 gene mutation) were enrolled in Department of Neurology, First Affiliated Hospital of Air Force Medical University from January 2018 to July 2023. Serum of the patients was collected for whole exon sequencing, and mutation sites and types of PRRT2 gene were analyzed. SWISS-MODEL website was used to predict the changes in protein structure caused by PRRT2 gene mutation. The relations of gene mutation type and clinical phenotype with prognosis of these patients were analyzed. Results:(1) All 18 patients with PRRT2 gene mutation were heterozygous mutation, including 12 frameshift mutations, 5 missense mutations, and 1 integer mutation. The clinical phenotype included benign familial infantile epilepsy (BFIE) in 5 patients, epilepsy in 6 patients, exercise-induced paroxysmal kinesigenic dyskinesia (PKD) in 5 patients, and infantile convulsion and choreoathetosis (ICCA) in 2 patients. A total of 8 mutation sites were found in 18 patients with PRRT2 gene mutation, of which 3 mutation sites have been reported, and 5 mutation sites have not been reported, including c.647(exon2)C>A, c.647(exon2)C>G, c.170(exon2)delC, c.981(exon3)C>G, and lossl(EXON: 2)(all). (2) Eighteen patients mainly accepted oxcarbazepine, levetiracetam, and sodium valproate in combination or monotherapy. Among them, 5 BFIE patients, 2 ICCA patients and 3 epilepsy patients were seizure-free after treatment. PKD patients did not respond well to oxcarbazepine. (3) Three frameshift mutations (mutation sites: c.649 [exon2]_c.650 [exon2] insC, c.640 [exon2]_c.641 [exon2] insC, and c.170 [exon2] delC) led to premature termination of protein translation, resulting in significant changes in protein structure. Four missense mutations (mutation sites: c.640[exo2]G>C, c.647[exon2]C>A, c.647[exon2]C>G, and c.981[exon3]C>G) had little effect on protein structure changes. No relation was found between changes of protein structure caused by different mutation types and prognosis. Conclusion:PRRT2 gene mutation patients with clinical phenotypes of BFIE and ICCA have good prognosis, but the mutation type is not related with the prognosis of patients.
