Mutation analysis and phenotypic investigation in patients with primary distal renal tubular acidosis / 中华肾脏病杂志

Objective:To analyze the gene variants in patients with primary distal renal tubular acidosis (dRTA), and explore the correlation between the genotype and phenotype.Methods:The Sanger direct sequencing or whole-exome sequencing was used to identify causal variants and the variation pathogenicity was evaluated according to 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines in 44 dRTA patients (37 families) diagnosed in the Affiliated Qingdao Municipal Hospital of Qingdao University and the Affiliated Hospital of Qingdao University from April 2010 to September 2020. The clinical features of the patients were summarized, and the correlation between the genotype and phenotype was investigated.Results:Seven variants of SLC4A1 gene, 17 variants of ATP6V0A4 gene, and 15 variants of ATP6V1B1 gene were identified in 44 patients with dRTA, and of which 11 variants were new ones. According to ACMG guidelines, the pathogenic, likely pathogenic, benign variants among the 39 variants were 22, 16 and 1, respectively. Nine patients were autosomal dominant hereditary dRTA caused by SLC4A1 gene mutation, 4 patients with autosomal recessive hereditary dRTA complicated with Southeast Asian ovalocytosis and anemia were caused by SLC4A1 gene mutation, and 14 patients caused by ATP6V0A4 gene mutation and 8 patients caused by ATP6V1B1 gene mutation were autosomal recessive hereditary dRTA; Two children with dRTA were found to carry one monoallelic defect in ATP6V1B1, and no causal gene mutation was identified in 7 patients. One patient showed incomplete dRTA, and the other 43 patients showed complete dRTA. The prevalence of sensory neural hearing loss caused by ATP6V0A4 and ATP6V1B1 mutation were 2/14 and 6/10 respectively. The frequency of chronic kidney disease in adults, children and infants were 4/4, 2/4, and 1/36, separately. After the drug treatment based on potassium citrate and sodium citrate, the growth and development (28/40) and electrolyte disturbance (41/44) of most patients were significantly improved. Conclusions:The present study has identified 39 variants of SLC4A1, ATP6V0A4 and ATP6V1B1 genes in 44 patients with dRTA, including 11 novel ones. There is a close relationship between genotype and phenotype in dRTA patients and most patients' conditions were improved after proper treatment. This study enriches the human gene mutation database and provides valuable references for diagnosis, treatment and genetic counseling in patients with dRTA.

Mutation analysis of KCNJ1 gene and investigation of phenotype in 5 Chinese patients with Bartter syndrome type 2 / 中华肾脏病杂志

Objective@#To identify and analyze the variants of the KCNJ1 gene in five Chinese patients with Bartter syndrome type 2 (BS2), and to describe their clinical features as well as treatment results.@*Methods@#Data and blood samples of five BS2 patients and their relatives confirmed by Qingdao Municipal Hospital from June 2012 to January 2019 were collected. Whole-exome-sequencing (WES) based on the second generation high throughput sequencing was performed to detect variants. The 2015 American College of Medical Genetics and Genomics Standards and Guidelines were applied to analyze the pathogenicity of the variants. The clinical features and laboratory results were retrospectively studied. The response to treatment and follow-up data were reviewed.@*Results@#Ten variants including six novel ones of KCNJ1 gene were identified through WES and verified by Sanger dideoxy sequencing. Missense variants accounted for the highest proportion. The common symptoms and signs of five BS2 patients from high to low incidence were polydipsia and polyuria (5/5), one of them (1/5) presented with diabetes insipidus; maternal polyhydramnios and premature delivery (4/5); growth retardation (3/5). Initially, two patients presented with hypochloremic metabolic alkalosis and hypokalemia, whereas the acid-base disturbance was absent in the others. One patient experienced hyperkalemia. In terms of calcium-phosphorus metabolism, one patient had evident parathyroid hormone (PTH) resistance (hypocalcemia, hyperphosphatemia and markedly elevated serum intact PTH levels), three presented with PTH overacting (hypercalcemia, hypophosphatemia and mild elevated serum intact PTH levels), and one showed normal blood calcium and phosphorus concentrations with high-normal serum intact PTH levels. All patients had nephrocalcinosis or hypercalciuria, and one of them complicated with nephrolithiasis. Indomethacin helped to correct the growth retardation, halt polydipsia polyuria, decrease the elevated urinary calcium excretion, and normalize electrolyte disturbance as well as PTH parameters in some patients.@*Conclusions@#This investigation identifies ten variants of KCNJ1 gene, including six ones that have not been previously reported, which will enrich the human gene mutation database (HGMD). These patients in our study have atypical BS phenotype, so that careful differentiation from other parathyroid diseases will be required for clinicians.

Mutation analysis of KCNJ1 gene and investigation of phenotype in 5 Chinese patients with Bartter syndrome type 2 / 中华肾脏病杂志

Objective:To identify and analyze the variants of the KCNJ1 gene in five Chinese patients with Bartter syndrome type 2 (BS2), and to describe their clinical features as well as treatment results. Methods:Data and blood samples of five BS2 patients and their relatives confirmed by Qingdao Municipal Hospital from June 2012 to January 2019 were collected. Whole-exome-sequencing (WES) based on the second generation high throughput sequencing was performed to detect variants. The 2015 American College of Medical Genetics and Genomics Standards and Guidelines were applied to analyze the pathogenicity of the variants. The clinical features and laboratory results were retrospectively studied. The response to treatment and follow-up data were reviewed.Results:Ten variants including six novel ones of KCNJ1 gene were identified through WES and verified by Sanger dideoxy sequencing. Missense variants accounted for the highest proportion. The common symptoms and signs of five BS2 patients from high to low incidence were polydipsia and polyuria (5/5), one of them (1/5) presented with diabetes insipidus; maternal polyhydramnios and premature delivery (4/5); growth retardation (3/5). Initially, two patients presented with hypochloremic metabolic alkalosis and hypokalemia, whereas the acid-base disturbance was absent in the others. One patient experienced hyperkalemia. In terms of calcium-phosphorus metabolism, one patient had evident parathyroid hormone (PTH) resistance (hypocalcemia, hyperphosphatemia and markedly elevated serum intact PTH levels), three presented with PTH overacting (hypercalcemia, hypophosphatemia and mild elevated serum intact PTH levels), and one showed normal blood calcium and phosphorus concentrations with high-normal serum intact PTH levels. All patients had nephrocalcinosis or hypercalciuria, and one of them complicated with nephrolithiasis. Indomethacin helped to correct the growth retardation, halt polydipsia polyuria, decrease the elevated urinary calcium excretion, and normalize electrolyte disturbance as well as PTH parameters in some patients. Conclusions:This investigation identifies ten variants of KCNJ1 gene, including six ones that have not been previously reported, which will enrich the human gene mutation database (HGMD). These patients in our study have atypical BS phenotype, so that careful differentiation from other parathyroid diseases will be required for clinicians.

Variant analysis and genotype/phenotype association study in 42 Chinese patients with Bartter syndrome type 3 / 中华肾脏病杂志

Objective To analyze the variants of 42 Chinese patients with Bartter syndrome type 3 (BS3) and explore the characteristics of genotype and phenotype. Methods Forty-two genetically diagnosed patients from 40 Han and one Hui families were collected in the Affiliated Hospital of Qingdao University and the Affiliated Qingdao Municipal Hospital of Qingdao University during the period of June 2012 to October 2018. The second-generation sequencing and multiplex ligase probe-dependent amplification (MLPA) technique were used to analyze the CLCNKB gene variation and its characteristics in children with BS3. The clinical data were collected, and the therapeutic effect and growth improvement were observed and followed up. Thirty eight patients were divided into severe (n=26) and light (n=12) groups according to the severity of genetic variation. The clinical phenotypic characteristics of the two groups were compared. Results Thirty-six variants including 16 novel ones of CLCNKB gene were found. The whole gene deletion of CLCNKB gene was the most frequent mutation (40％), and the rate of large deletions was up to 55％. The most common symptoms included development retardation (38/42), polydipsia and polyuria (35/42), constipation (31/42) and vomiting (27/42). All patients presented with hypokalemia, hypochloremia and metabolic alkalosis. After the medicine treatment that based on indomethacin and potassium chloride, most patients could achieve obvious recovery of growth rate and restoration of hypokalemia. The severe group showed more severe metabolic alkalosis than the light group. Conclusions Thirty-six variants of CLCNKB gene have been found in this study, including 16 novel ones, which enrich the human gene mutation database (HGMD) and provide valuable references to diagnosis, treatment and the genetic counseling of Chinese population.

Mutation analysis of SLC5A2 gene and determination of the renal threshold for glucose excretion in Chinese patients with familial renal glucosuria / 中华肾脏病杂志

Objective To analyze and identify the mutations in SGLT2 gene of nine Chinese families with FRG, and determine the renal threshold for glucose excretion (RTG), so as to explore the association of genotype and RTG. Methods All coding regions of SGLT2 gene, including intron exon boundaries, were analyzed using PCR followed by direct sequence analysis. Quantitative test for 24?hour urine glucose and RTG were measured among 9 probands (21 patients) and their family members from 9 pedigrees (total 25 subjects). The differences in renal glucose thresholds between patients with different genotypes (heterozygotes and compound heterozygotes; c.886(-10_-31) del heterozygotes and other heterozygotes) were compared. Results Twelve mutations were identified by SGLT2 gene analysis, including 10 novel ones that were not included in HGMD:c.331T>C, p.W111R;c.374T>C, p.M125T; c.394C>T, p.R132C; c.612G>C, p.Q204H; c.829C>T, p.P277S; c.880G>A, p.D294N;c.1129G>A, p.G377S; c.1194C>A, p.F398L; c.1540C>T, p.P514S; c.1573C>T, p.H525Y. In thisstudy, the mutation c.886(-10_-31)del that is specific to Chinese population accounted for about 28％of the total alleles (5/18). The RTG values of patients with compound heterozygous mutations were much lower than those with simple heterozygous mutations [(1.28 ±0.10) vs (5.14±0.77) mmol/L; P<0.001];and c.886(-10_-31)del heterozygotes had significant lower RTG values than others [(4.43 ± 0.37) vs (5.70 ± 0.51) mmol/L, P<0.001]. Conclusions Ten novel mutations which may be related to FRG are found in this study, and c.886(-10-31)del may be a hot?spot mutation in Chinese patients. Compound heterozygotes had much lower RTG values than simple heterozygotes.

Mutation analysis of SLC12A1 gene in nine Chinese patients with Bartter syndrome type Ⅰ / 中华肾脏病杂志

Objective To analyze the mutations of SLC12A1 gene in nine Chinese families with Bartter syndrome type I (BS1),and analyze the relationship between genotype and phenotype.Methods The next generation sequencing was used to detect mutations in nine BS1 patients including eight with antenatal BS (aBS) and one with classical BS (cBS).Clinical characteristics and biochemical findings at the first admission as well as follow-up were reviewed.Results 15 different mutations of SLC12A1 gene were identified,including 11 novel ones.Among nine probands,seven were compound heterozygotes,two were homozygotes.All patients presented with polydipsia and polyuria,and eight with growth retardation.All patients had lower than-normal serum chloride concentration,metabolic alkalosis,and elevated basal renin activity and aldosterone,and seven had hypokalemia.Through treatment of indomethacin and/or potassium chloride,biochemical indicators could roughly restored normal.Conclusion These findings will enrich the human gene mutation database (HGMD) and provide valuable references to the genetic counseling and diagnosis for Chinese population.

Mutation analysis of 5 children with primary distal renal tubular acidosis / 中华肾脏病杂志

Objective To analyze the mutations of causal genes in 5 children with primary distal renal tubular acidosis (dRTA),and explore their association of genotype and phenotype,so as to raise the awareness of the disease.Methods The whole exome sequencing was used to identify mutations in these 5 children from 5 families.Results A total of 4 different mutations of ATP6V0A4 gene were found in 2 dRTA children,including a novel heterozygous intron mutation (c.639 + 1G＞ A),a reported heterozygous nonsense variant (c.580C ＞T,p.Arg194*) and 2 novel heterozygous duplications (c.1504dupT,p.Tyr502Leufs*22;c.2351dupT,p.Phe785Ilefs*28).Two novel heterozygous missense mutations of ATP6V 1B 1 gene (c.409C ＞ T,p.Pro 137Ser;c.904C ＞ T,p.Arg302Trp) were identified in the third child,and a heterozygous missense mutation of SLC4A1 gene (c.1765C ＞ A,p.Arg589Ser) previously reported was found in the fourth child.No mutation of the dRTA-related causal genes was found in the fifth child.Furthermore,the mutations of causal genes in each of the first three children were compound heterozygous,which were consistent with the autosomal recessive inheritance pattern,and the variant from the fourth child was de novo.Conclusions The present study has found 7 mutations,including 5 novel variants,which enriches the human gene mutation database (HGMD) and contributes to a better understanding of the disease mechanisms.

Genotype, phenotype, and follow-up of Chinese patients with Gitelman's syndrome / 中华内分泌代谢杂志

Objective To analyze the characteristics of the genotype, phenotype, and follow-up of Gitelman's syndrome (GS) in the largest group of Chinese patients. Methods Sixty seven patients with GS underwent SLC12A3 gene analysis. Clinical characteristics and biochemical findings at the first presentation as well as follow-up were reviewed. Additionally, the associations of genotypes and phenotypes were explored. Results Forty-one different SLC12A3 mutations were identified in 67 patients with GS, including 11 novel ones, and 5 recurrent ones. 3 families (5. 7% ) had triple SLC12A3 mutations. Typical hypocalciuria and hypomagnesemia were not found in 6(9% ) and 8 (11. 9% )patients, respectively. In addition, male patients had an earlier age of onset and a higher urinary fraction excretion of electrolytes. 2 patients presented with chronic kidney disease, 13 (19. 4% ) with type 2 diabetes, 14 (20. 9% )with impaired glucose tolerance, and 5(7. 5% ) with impaired fasting glucose. Conclusion This study revealed 41 mutations in 67 Chinese patients with GS, including 11 novel variants and 5 high-frequency ones. Fraction excretion of electrolyte in urine may be more sensitive in the evaluation of phenotype compared with those of blood. It is difficult to correct hypokalemia and hypomagnesemia in GS. Patients with GS are at higher risk of the development of diabetes than ordinary people.

Mutation analysis of an adult patient with fructose-1,6-bisphosphatase deficiency in a Chinese family / 中华内分泌代谢杂志

The gene mutations of a patient with fructose-1,6-bisphosphatase (FBPase) deficiency and her parents were analyzed and her clinical manifestations, laboratory tests, and genetic characteristics were reviewed. The molecular analysis of FBP1 gene showed a G residue duplication at base 960 in exon 7(c. 960dupG) in this patient while her parents carried the heterozygous c. 960dupG mutation. The prominent clinical feature of this patient was the benign course of the disease with age. However, acute attack could be triggered by stress, long-time fasting, a large amounts of fructose intake, etc. The typical clinical manifestations were severe lactic acidosis, hypoglycemia, and elevated liver enzymes.

Research advances in retroperitoneal fibrosis / 中华老年医学杂志

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the development of inflammation and fibrosis in the soft tissues of the retroperitoneum and other abdominal organs.RPF can be divided into two types:idiopathic and secondary.Some of the previously diagnosed idiopathic retroperitoneal fibrosis cases belong to the IgG4-related disease category.In order to help clinicians to achieve better diagnostic accuracy,the article reviews current national and international research on this disorder,and summarizes the epidemiological characteristics,the pathogenesis,the clinical manifestations,the microscopicand imaging features,and the most recent advances in the management of RPF.

Mutation analysis of an adult patient with fructose-1,6-bisphosphatase deficiency in a Chinese family / 中华内分泌代谢杂志

The gene mutations of a patient with fructose-1,6-bisphosphatase (FBPase) deficiency and her parents were analyzed and her clinical manifestations, laboratory tests, and genetic characteristics were reviewed. The molecular analysis of FBP1 gene showed a G residue duplication at base 960 in exon 7(c. 960dupG) in this patient while her parents carried the heterozygous c. 960dupG mutation. The prominent clinical feature of this patient was the benign course of the disease with age. However, acute attack could be triggered by stress, long-time fasting, a large amounts of fructose intake, etc. The typical clinical manifestations were severe lactic acidosis, hypoglycemia, and elevated liver enzymes.

Research advances in retroperitoneal fibrosis / 中华老年医学杂志

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the development of inflammation and fibrosis in the soft tissues of the retroperitoneum and other abdominal organs.RPF can be divided into two types:idiopathic and secondary.Some of the previously diagnosed idiopathic retroperitoneal fibrosis cases belong to the IgG4-related disease category.In order to help clinicians to achieve better diagnostic accuracy,the article reviews current national and international research on this disorder,and summarizes the epidemiological characteristics,the pathogenesis,the clinical manifestations,the microscopicand imaging features,and the most recent advances in the management of RPF.

Gene analysis, treatment, and follow-up of sixteen Chinese patients with Bartter syndrome / 中华肾脏病杂志

Objective To analyze the mutations of causal genes in sixteen Chinese patients with suspicious Bartter syndrome,and follow up their treatment results.Methods Mutations were identified by the next generation sequencing and the multiplex ligation-dependent probe amplification (MLPA).Clinical and biochemical features at the first presentation as well as follow-up results were reviewed.Results 15 different CLCNKB gene mutations were identified in sixteen patients with BS,including 11 novel ones.A novel missense mutation and a novel small deletion were found from SLC12A1 gene.A novel gross deletion was found in CLCNKA gene.A recurrent missense mutation was identified from BSND gene.The whole gene deletion mutation of CLCNKB gene was the most frequent mutation (32％),and the rate of gross deletion was up to 50 percent in this group of Chinese patients.The most common clinical manifestations were development retardation (15/16),polydipsia and polyuria (15/16).All of the patients were detected with hypokalemia,hypochloremia and metabolic alkalosis.Indomethacin treatment had significant improvement to the stature and weight restoration.Conclusion The present study has found 19 mutations,including 14 novel ones,which enriches the human gene mutation database (HGMD) and provides valuable references to the genetic counseling and diagnosis of Chinese population.

Clinical analysis of 36 cases of IgG4-related disease / 中华肾脏病杂志

Objective To explore the clinical characteristics of IgG4-related disease (IgG4-RD) in Chinese by detailed clinicopathological and laboratory assessments.Methods The baseline features of 36 patients with biopsy-proven disease were reviewed.The diagnosis was confirmed by pathology review according to consensus diagnostic criteria and clinicopathologic correlation.Disease activity and damage were assessed by the IgG4-RD responder index (RI).Results Thirty (83.3％) of the patients were male,while six were female,and the average age of onset was 65.1 years.All of the 36 patients had active disease,in which submandibular gland,lymph nodes,retroperitoneal tissue were the most common affected organs in this group of patients.Among 36 patients,77.7％ had elevated serum IgG4 concentrations and 44.4％ had hypocomplementemia.Patients with elevated serum IgG4 had a higher RI,a greater number of organs involved (P ＜ 0.01 for all comparisons).The correlation between serum IgG4 level and RI (r=0.737,P ＜ 0.01) was stronger than IgG,ESR,CRP and serum complement levels.The incidence of hypocomplementemia in IgG4-RD patients with renal involvement was higher than that in IgG4-RD patients with other organs involvement (P ＜ 0.01).Twenty-eight patients received glucocorticoids therapy,and had lower RI and serum IgG4 concentration after therapy (P ＜ 0.05).Conclusions Both IgG4-RD RI and IgG4 concentration may be regarded as assessment markers of disease activity and therapeutic effect of IgG4-RD.The diagnosis of IgG4-RD should be supported by histopathology and clinical features.

Analysis on the mutation of SLC5A2 gene in Chinese patients with familial renal glucosuria and investigation on the association of genotype and phenotype / 中华肾脏病杂志

Objective To describe and analyze the clinical characters of patients with FRG from 7 Chinese families.Then analyze and identify their mutations in SGLT2 gene,and explore the association of genotype and phenotype.Methods Quantitative test for 24-hour urine glucose and other laboratory tests were carried out among 7 probands (14 patients in all) and their family members from 7 pedigrees (totaling 23 subjects).All coding regions,including intron-exon boundaries,were analyzed using PCR followed by direct sequence analysis.Results Five novel mutations in SLC5A2 gene were identified in this investigation,including four missense mutations (A Serine to Glycine at position 335 (c.1003A＞G,p.S335G),a Glutamine to Arginine at position 448 (c.1343A ＞ G,p.Q448R),an alanine to proline at position 474 (p.A474P,c.1420G ＞ C) and a glycine to aspartic acid at position 580 (c.1739G ＞ A,p.G580D) and a deletion in intron 7 (c.886(-10_-31)del).By the minigene studies using the pSPL3 plasmids,we confirmed the deletion c.886(-10_-31)del as a splicing mutation.In this study,the mutation c.886(-10_-31)del accounted for about 43％ of the total alleles (12/28).These patients with compound heterozygous or homozygous mutations manifested middle degree or severe glycosuria (Quantitative test for 24-hour urine glucose:10.56-50.68 g/1.73 m2),however those with heterozygous variants presented with mild to moderate glycosuria (Quantitative test for 24-hour urine glucose ≤ 2.45 g/1.73 m2).This fits co-dominant inheritance pattern.Conclusions Five novel mutations which may be related to FRG are found in this study,and c.886(-10-31) del may be a high frequency mutation in Chinese patients.

Analysis of mutant genes in a primary hyperoxaluria type Ⅲ family / 中华肾脏病杂志

Objective To describe the clinical characteristics of one child with primary hyperoxaluria types Ⅲ, and to analyze the potential mutant genes in his family.Methods AGXT, GRHPR and HOGA1 genes were analyzed by direct sequencing analysis in this family.One hundred unrelated healthy subjects were also analyzed as controls.Results The child had early onset of symptoms (0.8 year).His principal clinical manifestation included nephrolithiasis and obstructive nephropathy, however his nephrocalcinosis was mild.And he presented high urine oxalate, high urine calcium, and lower citrate levels.Two novel heterozygous mutations in HOGA1 were identified (compound heterozygous), one mutation was a 2-bp substitution at the last position in exon 6 and the first position of intron 6 respectively (c.834_834 + 1GG ＞ TT);another was a guanine to adenine substitution of the last nucleotide of exon 6 (c.834G ＞ A).Both of these variants found in this study probably acted as splicing mutations.Direct sequencing analysis failed to find these mutations in 100 unrelated healthy subjects.In addition, a SNP (c.715G ＞ A, p.V239I) was found in this family.There were no mutations detected in AGXT and GRHPR.Conclusions Two novel mutations are identified probably in association with PH Ⅲ.This is the first description and investigation on mutant gene analysis of PHⅢ in Asia.

Analysis of AGXT gene mutation in a primary hyperoxaluria type Ⅰ family / 中华肾脏病杂志

Objective To describe the clinical characteristics,and to analyze the AGXT gene mutation in three siblings with primary hyperoxaluria type I (PHI).Methods AGXT gene mutation was analyzed by direct sequencing analysis in this family,and the minor allele status was also tested.One hundred unrelated healthy subjects were also analyzed as controls.Results Three mutations in AGXT were identified in each of three patients including two novel heterozygous missense mutations and one previously reported variant.One mutation was a methionine to leucine substitution at position 49 (p.M49L,c.145A ＞ C) in exon 1,one was an asparagine to isoleucine transition at codon 72 (p.N72I,c.215A ＞ T) in exon 2,and another was a heterozygous nonsense mutation at codon 333 (p.R333*).Both p.M49L and p.R333* occured in cis configuration with the minor allele IVS1 +74 bp.Conclusions Two novel mutations are identified probably in association with PHI,however their pathogenicity and potential molecular mechanisms should be explored by further investigations.This is the first investigation on mutant gene analysis of PHI in China.

Mutation analysis of ATP6V0A4 and ATP6V1B1 gene in autosomal recessive distal renal tubular acidosis children / 中华肾脏病杂志

Objective To analyze and identify the mutations of ATP6V0A4 and ATP6V1B1 gene in autosomal recessive distal renal tubular acidosis (rdRTA) children,and study the association of genotype and phenotype. Methods Genome DNA was amplified by PCR.Mutations of ATP6V0A4 and ATP6V1B1 gene in 3 children from 3 families were examined by direct sequencing.One hundred unrelated healthy subjects were selected to evaluate all mutations found in this study. Results A novel homozygous nonsense mutation was identified in ATP6VOA4 gene in one child, and a novel heterozygous nonsense variant and a frame-shift alteration were found in another child.No mutation of both genes was found in the third child.Conclusions Study of mutant genes of rdRTA in Chinese patients is helpful to understand the association in genotype and phenotype and increase the level of cognition and treatment to this disease.

Coexistence of Gitelman's syndrome and thyroid disease: SLC12A3 gene analysis in two patients / 中华内分泌代谢杂志

Two patients with coexistence of thyroid disease and suspected Gitelman's syndrome underwent SLC12A3 gene analysis. The results confirmed that both patients were compound heterozygotes of SLC12A3 gene mutation. Three novel variants of SLC12A3 were found in this study. This report suggests that Gitelman's syndrome may coexist with other disorders associated with hypokalemia, such as Graves' disease.

Mutations of WNK gene in patients with hypokalemic salt-losing tubulopathies / 上海交通大学学报（医学版）

Objective To explore the molecular mechanisms involved in hypokalemic salt-losing tubulopathies ( SLTs) through genetic screening of WNK gene in patients with SLTs. Methods Forty-four kindreds of SLTs were diagnosed Batter's syndrome or Gitelman's syndrome after CLCNKB and SLC12A3 sequencing and analysis, 8 of whose phenotype can not be simply attributed to CLCNKB or SLC12A3 mutations. Primers for PCR-amplified exons of WNK4 and WNK1 gene in genomic DNA were designed, and direct sequencing was performed to analyse the PCR products. Results Two missense mutations of WNK1, Ile~(1172)→ Met (I1172M) and Ser~(2047) → Asn (S2047N), were identified. Both of these 2 mutations segregated with the disease in SLTs kindred. Conclusion Two heterozygote missense mutations of WNK1 gene (I1172 M and S2047N) were found in 8 SLTs kindreds, indicating that WNK1 might be another gene responsible for hypokalemic salt-losing tubulopathies.