二例SLC12A3基因复合杂合变异所致Gitelman综合征的遗传学分析

doi:10.12280/gjszjk.20250134

摘要/Abstract

摘要： 目的：总结2 例Gitelman 综合征患者的分子遗传学分析经验。方法：2 例患者因反复发作的低血钾症就诊，临床高度怀疑Gitelman 综合征。收集患者及其父母的外周静脉血样，提取基因组DNA，进行全外显子组测序（whole exome sequencing，WES）并分析结果。结果：经家系WES（trio-WES）数据分析，检测到2 例患者的SLC12A3 基因存在复合杂合变异，变异位点分别为c.965-1_976delinsACCGAAAATTTT 和c.1964G>A、c.486_491delinsAC 和c.2178+1G>T，父母均为表型正常的突变位点携带者，Sanger 测序结果与trio-WES 结果一致。结论：SLC12A3 基因复合杂合致病性变异可能是这2 例患者的遗传学病因，扩展了该基因的致病变异谱。对于可疑Gitelman 综合征患者，应完善患者及其家系的基因检测以明确诊断，提供更全面的遗传咨询和更精确的再生育产前诊断。

关键词: Gitelman 综合征, 溶质载体家族12，成员3, 全外显子组测序, 突变, 低钾血症

Abstract:

Objective: To summarize the experience of molecular genetic analysis of two patients with Gitelman syndrome. Methods: Two patients admitted to our hospital due to recurrent hypokalemia were highly suspected as Gitelman syndrome in clinical. Peripheral venous blood samples were collected from the patients and their parents. Genomic DNA was extracted and analyzed by whole exome sequencing(WES). Results: The trio-WES analysis showed that two patients had the compound heterozygous variations in the SLC12A3 gene. The variation sites were c.965 -1_976delinsACCGAAAATTTT and c.1964G >A in one patient, and c.486_491delinsAC and c.2178+1G>T in another patient. Both parents were carriers of the mutant sites with normal phenotypes. The results of Sanger sequencing were consistent with those of trio-WES. Conclusions: The compound heterozygous pathogenic variations in the SLC12A3 gene may be the genetic cause of these two patients, which expands the spectrum of pathogenic variations of this gene. For those patient suspected as Gitelman syndrome, the genetic testing of the patient and parents should be completed, so as to make a clear diagnosis, provide more comprehensive genetic counseling and more accurate prenatal diagnosis for subsequent pregnancies.

Key words: Gitelman syndrome, Solute carrier family 12, member 3, Whole exome sequencing, Mutation, Hypokalemia

陈雪, 田芯瑗, 郑雷, 马盼盼, 张钏, 惠玲, 周秉博. 二例SLC12A3基因复合杂合变异所致Gitelman综合征的遗传学分析[J]. 国际生殖健康/计划生育杂志, 2025, 44(5): 366-370.

CHEN Xue, TIAN Xin-yuan, ZHENG Lei, MA Pan-pan, ZHANG Chuan, HUI Ling, ZHOU Bing-bo. Genetic Analysis of Two Cases of Gitelman Syndrome Caused by Compound Heterozygous Variations in the SLC12A3 Gene[J]. Journal of International Reproductive Health/Family Planning, 2025, 44(5): 366-370.

图/表 4

表1 Sanger测序验证的引物序列

病例	基因	染色体位置	转录本外显子	基因变异	引物编号	引物序列（5′→3′）	片段长度（bp）
例1	SLC12A3	chr16:56920314	NM_001126108.1;Exon16	c.1964G>A (p.Arg655His)	SLC12A3-c1964-F	CCTGGATTTATAGG TGGGAAGC	414
		chr16:56920314	NM_001126108.1;Exon16	c.1964G>A (p.Arg655His)	SLC12A3-c1964-R	ACTCTGTGGGTGGA CATCACAC	414
		chr16:56906567	NM_001126108.1;IVS7	c.965-1G>A	SLC12A3-c966-F	GCTCTGGGGACAGG GACTC	465
		chr16:56906567	NM_001126108.1;IVS7	c.965-1G>A	SLC12A3-c966-R	CGGAATGGAATCGG TTGG	465
例2	SLC12A3	chr16:56902264- 56902269	NM_001126108.1;Exon3	c.486_491delin sAC (p.Thr163 Profs*7)	SLC12A3-c489-F	TCTCACCCTCTTGC CCCATA	366
		chr16:56902264- 56902269	NM_001126108.1;Exon3	c.486_491delin sAC (p.Thr163 Profs*7)	SLC12A3-c489-R	TGCACCTCAAGTTT AATCCTGC	366
		chr16:56921006	NM_001126108.1;IVS17	c.2178+1G>T	SLC12A3-c2178-1-F	CAAGTGGCTGAACA AGAGGAA	173
		chr16:56921006	NM_001126108.1;IVS17	c.2178+1G>T	SLC12A3-c2178-1-R	CGGAATGGAATCGG TTGG	173

图1 病例1及其父母SLC12A3基因的Sanger测序结果注：A 患儿为c.965-1_976delinsACCGAAAATTTT杂合变异，遗传自表型正常的父亲；B 患儿为c.1964G>A杂合变异，遗传自表型正常的母亲

图2 病例2及其父母SLC12A3基因的Sanger测序结果注：A 患者为c.486_491delinsAC杂合变异，遗传自表型正常的父亲；B 患者为c.2178+1G>T杂合变异，遗传自表型正常的母亲

图3 SLC12A3基因编码的NCC蛋白p.Arg655His突变3D结构模拟分析注：野生型（WT）SLC12A3基因编码的NCC蛋白中Arg和His都是极性碱性氨基酸，而突变型（MUT）SLC12A3基因编码的NCC蛋白中的Arg655被His655取代后，His655与Leu658、Val659相互作用形成氢键，而与Thr649之间的氢键消失，这可能导致NCC蛋白结构稳定性遭到破坏

参考文献 16

[1]	Yang M, Dong Y, Tian J, et al. A novel compound heterozygous mutation of SLC12A3 gene in a pedigree with Gitelman syndrome and literature review[J]. Genes Genomics, 2020, 42(9):1035-1040. doi: 10.1007/s13258-020-00960-6.
[2]	中国研究型医院学会罕见病分会, 中国罕见病联盟, 北京罕见病诊疗与保障学会, 等. Gitelman综合征诊疗中国专家共识(2021版)[J]. 罕见病研究, 2022, 1(1):56-67. doi: 10.12376/j.issn.2097-0501.2022.01.010.
[3]	Xia MF, Bian H, Liu H, et al. Hypokalemia, hypomagnesemia, hypocalciuria, and recurrent tetany: Gitelman syndrome in a Chinese pedigree and literature review[J]. Clin Case Rep, 2017, 5(5):578-586. doi: 10.1002/ccr3.874.
[4]	Subasinghe CJ, Sirisena ND, Herath C, et al. Novel mutation in the SLC12A3 gene in a Sri Lankan family with Gitelman syndrome & coexistent diabetes: a case report[J]. BMC Nephrol, 2017, 18(1):140. doi: 10.1186/s12882-017-0563-0.
[5]	Zeng Y, Li P, Fang S, et al. Genetic Analysis of SLC12A3 Gene in Chinese Patients with Gitelman Syndrome[J]. Med Sci Monit, 2019, 25:5942-5952. doi: 10.12659/MSM.916069.
[6]	Clemente-Suárez VJ, Martín-Rodríguez A, Redondo-Flórez L, et al. Epithelial Transport in Disease: An Overview of Pathophysiology and Treatment[J]. Cells, 2023, 12(20):2455. doi: 10.3390/cells12202455.
[7]	Jiang L, Peng X, Zhao B, et al. Frequent SLC12A3 mutations in Chinese Gitelman syndrome patients: structure and function disorder[J]. Endocr Connect, 2022, 11(1):e210262. doi: 10.1530/EC-21-0262.
[8]	Luo J, Yang X, Liang J, et al. A pedigree analysis of two homozygous mutant Gitelman syndrome cases[J]. Endocr J, 2015, 62(1):29-36. doi: 10.1507/endocrj.EJ14-0289. pmid: 25273610
[9]	Gug C, Mihaescu A, Mozos I. Two mutations in the thiazide-sensitive NaCl co-transporter gene in a Romanian Gitelman syndrome patient: case report[J]. Ther Clin Risk Manag, 2018, 14:149-155. doi: 10.2147/TCRM.S150483.
[10]	Bi Y, Kuang MY, Li ML. Novel heterozygous mutations of SLC12A3 gene in a Chinese pedigree with Gitelman syndrome: A care-compliant case report[J]. Medicine(Baltimore), 2023, 102(35):e34967. doi: 10.1097/MD.0000000000034967.
[11]	Ravarotto V, Loffing J, Loffing-Cueni D, et al. Gitelman′s Syndrome: characterization of a novel c.1181G>A point mutation and functional classification of the known mutations[J]. Hypertens Res, 2018, 41(8):578-588. doi: 10.1038/s41440-018-0061-1. pmid: 29925901
[12]	Lü Q, Zhang Y, Song C, et al. A novel SLC12A3 gene homozygous mutation of Gitelman syndrome in an Asian pedigree and literature review[J]. J Endocrinol Invest, 2016, 39(3):333-340. doi: 10.1007/s40618-015-0371-y. pmid: 26260218
[13]	Ganguli A, Veis JH. Hyponatremia-A rare complication of Gitelman′s syndrome[J]. Indian J Nephrol, 2017, 27(1):74-77. doi: 10.4103/0971-4065.177208. pmid: 28182047
[14]	Filippatos TD, Rizos CV, Tzavella E, et al. Gitelman syndrome: an analysis of the underlying pathophysiologic mechanisms of acid-base and electrolyte abnormalities[J]. Int Urol Nephrol, 2018, 50(1):91-96. doi: 10.1007/s11255-017-1653-4. pmid: 28744758
[15]	Chubanov V, Köttgen M, Touyz RM, et al. TRPM channels in health and disease[J]. Nat Rev Nephrol, 2024, 20(3):175-187. doi: 10.1038/s41581-023-00777-y.
[16]	Reyes JV, Medina P. Renal calcium and magnesium handling in Gitelman syndrome[J]. Am J Transl Res, 2022, 14(1):1-19. pmid: 35173827