Advances in the treatment of Alport syndrome / 国际儿科学杂志

Alport syndrome(AS)is a hereditary nephropathy associated with hematuria, proteinuria and progressive kidney failure.It is characterized by a defective glomerular basement membrane caused by mutations in type Ⅳ collagen genes COL4A3/A4/A5, which result in defective in the type Ⅳa3, a4 and a5 chains respectively.At present, there is no preventive or curative therapies for AS.Inhibitors of the renin angiotensin aldosterone system are routinely used to slow the progression of kidney disease and prolong life expectancy.Ramipril was found in retrospective studies to delay the onset of end stage renal disease(ESRD), supporting that early initiation of renin angiotensin aldosterone system blockade is very important.Advances in our understanding on the pathogenesis of AS has culminated in the development of innovative therapeutic approaches that are currently under investigation.This review will briefly outline novel therapeutic targets for the prevention of renal disease progression in AS.

COL4A5 genotypes and clinical characteristics of children with Alport syndrome / 中国当代儿科杂志

OBJECTIVES@#To investigate the genotypes of the pathogenic gene COL4A5 and the characteristics of clinical phenotypes in children with Alport syndrome (AS).@*METHODS@#A retrospective analysis was performed for the genetic testing results and clinical data of 19 AS children with COL4A5 gene mutations.@*RESULTS@#Among the 19 children with AS caused by COL4A5 gene mutations, 1 (5%) carried a new mutation of the COL4A5 gene, i.e., c.3372A>G(p.P1124=) and presented with AS coexisting with IgA vasculitis nephritis; 3 children (16%) had large fragment deletion of the COL4A5 gene, among whom 2 children (case 7 had a new mutation site of loss51-53) had gross hematuria and albuminuria at the onset, and 1 child (case 13 had a new mutation site of loss3-53) only had microscopic hematuria, while the other 15 children (79%) had common clinical phenotypes of AS, among whom 7 carried new mutations of the COL4A5 gene. Among all 19 children, 3 children (16%) who carried COL4A5 gene mutations also had COL4A4 gene mutations, and 1 child (5%) had COL4A3 gene mutations. Among these children with double gene mutations, 2 had gross hematuria and proteinuria at the onset.@*CONCLUSIONS@#This study expands the genotype and phenotype spectrums of the pathogenic gene COL4A5 for AS. Children with large fragment deletion of the COL4A5 gene or double gene mutations of COL4A5 with COL4A3 or COL4A4 tend to have more serious clinical manifestations.

Bilateral giant full thickness macular holes: an infrequent manifestation of alport syndrome

Purpose: To report a case of Alport syndrome presenting with bilateral giant full-thickness macular holes, hypertensive chorioretinopathy, and exudative retinal detachment. Case Report: A 20 year-old man, a known case of Alport syndrome on hemodialysis, was referred to our clinic with bilateral vision loss initiated about 10 years prior to presentation, which exacerbated in the month prior to our visit. Bilateral large full-thickness macular holes, hypertensive chorioretinopathy, and exudative retinal detachment were detected in fundus examination. The patient had previous genetic counseling confirming the diagnosis of Alport syndrome. During follow-up, macular holes were covered with a thick epiretinal membrane and visual acuity decreased progressively in two weeks. Pars plana vitrectomy was performed in the right eye. Two weeks following surgery, the macular hole was closed and visual acuity improved significantly. Conclusion: Bilateral giant full-thickness macular holes are uncommon presentations of Alport syndrome. The retinal findings may be caused by an inefficient type IV collagen presenting in the Bruch's membrane and in the internal limiting membrane. Pars plana vitrectomy can be considered to repair macular holes in these patients.

Deciphering the pathogenicity of COL4A4 heterozygous splicing mutations and the genotype-phenotype correlation in autosomal dominant Alport syndrome / 中华肾脏病杂志

Objective:Through the investigation of the pathogenicity of COL4A4 heterozygous splicing mutations and the genotype-phenotype correlation in autosomal dominant Alport syndrome (ADAS), to better understand the impact of COL4A4 heterozygous splicing mutations on ADAS. Methods:The study was a case series analysis. Patients from 5 ADAS families with COL4A4 heterozygous splicing mutations detected by whole exome sequencing were recruited by three hospitals. In vivo transcriptional analysis and/or in vitro minigene splicing assay were conducted to determine the splicing patterns and assess the pathogenicity of COL4A4 heterozygous splicing mutations. Results:In the five ADAS pedigrees carrying COL4A4 heterozygous splicing mutations, four novel ADAS splicing patterns were described. In pedigree 1-4, most patients presented with continuous hematuria or/and microalbuminuria. Otherwise,the proband in pedigree 4 presented with macroalbuminuria and the proband in pedigree 1 had progressed to chronic kidney disease stage 2 at the age of 70 years old. In pedigree 5, all patients developed end-stage renal disease between 28 and 41 years old. c.735+3A>G detected in pedigree 1 and pedigree 2 and c.694-1G>C detected in pedigree 3 both led to exon 12 skipping in COL4A4, resulting in 42 nucleotides in-frame deletion (c.694_735del). c.2056+3A>G detected in pedigree 4 led to COL4A4 exon 26 skipping, which caused in-frame deletion of 69 nucleotides (c.1988_2056del). c.2716+5G>T detected in pedigree 5 led to a 360 nucleotides large in-frame deletion, including 100 bp sequence at the 3'end of exon 29,the whole sequence of exon 30 and 89 bp sequence at the 5'end of exon 31 (c.2446_2805del). Conclusions:Renal prognosis differs significantly for patients with small in-frame deletions versus large in-frame deletion splicing abnormalities. Determination of the pathogenicity and the splicing patterns of COL4A4 heterozygous splicing mutations using in vivo and in vitro transcriptional analysis may provide renal prognostic information.

Fenotipos inesperados en el síndrome de Alport: la necesidad del estudio genético / Unexpected phenotypes in Alport syndrome: the need for genetic testing

El diagnóstico del síndrome de Alport supone un reto en la edadpediátrica, debido a la ausencia de fenotipos clínicos esperados de la enfermedad, su clásica caracterización de entidad rara y la práctica muy restringida de biopsias renales con análisis rutinario de la muestra por microscopía electrónica durante la infancia. Se presentan las características clínicas y genéticas de 6 pacientes pediátricos (4 mujeres) diagnosticados de síndromede Alport en dos centros hospitalarios entre 2018 y 2021. Todos los pacientes presentaron un debut clínico claramente diferente y ninguno presentó complicaciones auditivas nioftalmológicas. La mitad carecía de antecedentes familiares de enfermedad renal crónica. Ninguna biopsia renal realizada confirmó el diagnóstico. Todos los pacientes fueron confirmadosgenéticamente y fueron el caso índice del estudio familiar. Esta serie ilustra la presencia de fenotipos clínicos inesperados en el síndrome de Alport y refleja la necesidad de incorporar el estudio genético para su diagnóstico.

The diagnosis of Alport syndrome is a challenge in the pediatric age, due to the absence of expected clinical phenotypes of the disease, its classic characterization of a rare disease and the very restricted practice of renal biopsies with routine analysis of the sample by electron microscopy during infancy. The clinical and genetic characteristics of 6 pediatric patients (4 women) diagnosed with Alport syndrome in two hospital centers between 2018 and 2021 are reported. All patients presented a clearly different clinical debut and none presented auditory or ophthalmological complications. Half had no family history of chronic kidney disease. No kidney biopsy performed confirmed the diagnosis. All patients were genetically confirmed and were the index case in the family study. This series illustrates the presence of unexpected clinical phenotypes in Alport syndrome and reflects the need for the incorporation of the genetic study for its diagnosis.

Whole-Exome Sequencing (WES) results of 50 patients with chronic kidney diseases: a perspective of Alport syndrome

SUMMARY OBJECTIVE: Chronic kidney disease (CKD) remains one of the major common health problems, and the number of people affected by the disease is progressively increasing in Turkey and worldwide. This study aimed to investigate molecular defects in Alport syndrome (AS) and other genes in patients with clinically suspected CKD using whole-exome sequencing (WES). METHODS: Patients with clinical suspicion of CKD were included in the study. Molecular genetic analyses were performed on genomic DNA by using WES. RESULTS: A total of 15 with 5 different pathogenic or likely pathogenic variants were identified in CKD patients, with a diagnostic rate of 30%. Eight variants of uncertain significance were also detected. In this study, 10 variants were described for the first time. As a result, we detected variants associated with CKD in our study population and found AS as the most common CKD after other related kidney diseases. CONCLUSIONS: Our results suggest that in heterogeneous diseases such as CKD, WES analysis enables accurate identification of underlying molecular defects promptly. Although CKD accounts for 10-14% of all renal dysfunction, molecular genetic diagnosis is necessary for optimal long-term treatment, prognosis, and effective genetic counseling.

Glomerulonefritis C3 en un paciente con síndrome de Alport: un caso raro

El síndrome de Alport es una entidad hereditaria que se produce principalmente por una mutación en los genes que codifican el colágeno tipo IV. Por otro lado, la glomerulonefritis C3 es una entidad rara que presenta un patrón de glomerulonefritis membranoproliferativa y su etiología se basa en un control anormal de la activación de la vía alternativa del complemento. A continuación se describe un caso de un paciente, de sexo masculino, que cursa con un síndrome nefrótico corticorresistente en el que se documenta un patrón de glomerulonefritis membranoproliferativa en la biopsia renal con depósitos de C3 en la inmunofluorescencia, asociada a una deleción heterocigota en el gen CFHR1 en el estudio genético de las proteínas reguladoras del complemento. Además, en el panel genético realizado por corticorresistencia se encuentra una variante COL4A5 asociada al síndrome de Alport ligado al X. Estas entidades pueden presentarse con un curso clínico diverso, pero al estar asociadas pueden acelerar la progresión a enfermedad renal crónica, por lo que se hace necesario hacer un seguimiento clínico más estricto.

Alport Syndrome is a hereditary entity that occurs mainly due to a mutation in the genes that encode type IV collagen. C3 glomerulonephritis is a rare entity with a pattern of membranoproliferative glomerulonephritis and its etiology is based on abnormal control of the activation of the alternative complement pathway. We describe a case of a male patient who presents with a corticosteroid nephrotic syndrome in which a pattern of membranoproliferative glomerulonephritis is documented in the renal biopsy with C3 deposits in the immunofluorescence, associated with a heterozygous deletion in the gene CFHR1 in the genetic study of complement regulatory proteins. Furthermore, a variant COL4A5 associated with X-linked Alport syndrome is found in the genetic panel for corticosteroid resistance. These entities can present with a diverse clinical course, but when associated they can accelerate progression to chronic kidney disease, which is why makes it necessary to do a more strict clinical follow-up.

Genotype and phenotype analysis of children with autosomal dominant inheritance Alport syndrome / 中华实用儿科临床杂志

Objective:To analyze the clinicopathological and gene mutation characteristics of children with autosomal dominant inheritance Alport syndrome (ADAS), and to improve the understanding of ADAS.Methods:Ten children with ADAS diagnosed in the Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from September 2016 to February 2020 were enrolled.The clinicopathological and gene mutation features were retrospectively analyzed, and the patients were followed up.Results:(1) The median age at diagnosis was 5.7 (2.4, 9.8) years.Of 10 children, 6 cases (60.0%) showed a family history of renal failure, 4 cases (40.0%) presented with hematuria and proteinuria at diagnosis, and 2 cases (20.0%) suffered a high-frequency hearing loss.Renal biopsy showed extensive splitting and lamellation of the glomerular basement membrane (GBM) dense layer in 4 cases (40.0%), and segmental splitting and lamellation in 6 cases (60.0%). (2)Among 10 children, 4 cases (40.0%) were heterozygous mutations of COL4A3 gene, including 2 point mutations of glycine, and 2 splicing mutations.The other 6 cases (60.0%) were heterozygous mutations of COL4A4 gene, including collagen glycine point mutations in 4 cases, nonsense mutation in 1 case and large deletion in 1 case.Six mutations were new and never reported before. Conclusions:The early clinical presentations of children with ADAS are often atypical and extrarenal manifestations are less common.The GBM dense layer is mainly featured by segmental splitting and lamellation.Glycine point mutations account for the majority of the gene mutations.

Thin basement membrane nephropathy combined with juvenile idiopathic arthritis caused by the COL4A4 gene mutation: a case report / 中华实用儿科临床杂志

To analyze a case of thin basement membrane nephropathy combined with juvenile idiopathic arthritis diagnosed in November 2017 in Children′s Hospital of Chongqing Medical University.A male patient with 7 years and 11 months old presented with swelling of bilateral interphalangeal joints and abnormal gait was diagnosed as juve-nile idiopathic arthritis.Urine examination revealed microscopic hematuria.Long-term follow-up after discharge showed recurrent joint symptoms and persistent microscopic hematuria.In February 2019, genetic testing showed the COL4A4 gene mutation (c.3479G>A p. G1160E). Through literature review, a case of rheumatoid arthritis complica-ted with Alport syndrome caused by the COL4A5 gene mutation c. 1351T>C (p.Cys451Arg) was previously reported.Both of 2 patients were diagnosed as collagen type Ⅳ-related renal diseases complicated with arthritis, and multiple joints involvement and renal involvement were detected.Excluding the influence of accidental factors and drugs, arthritis and some kidney diseases may have a co-pathogenesis under genetic background.The specific mechanism needs further exploration.This case report provided novel direction for the diagnosis and treatment of relevant diseases.

Clinical, Pathological and Genetic Analysis of Alport Syndrome in Children / 罕见病研究

  Objective  To explore the phenotype-genotype correlation of Alport syndrome in children.  Methods  Retrospectively analyze the clinical and pathological features of 55 patients with Alport syndrome with COL4A mutations detected by second-generation sequencing, who were treated at Beijing Children's Hospital from January 2016 to December 2020.  Results  A total of 55 children with Alport syndrome were included. All cases had hematuria, including 31 cases (56.4%) with gross hematuria and 24 cases (43.6%) with microscopic hematuria. A total of 39 (70.9%) patients also had proteinuria. Extrarenal manifestations were pres- ent in 12 patients (21.8%). 36(65.4%) patients had a family history of Alport syndrome. 32 patients underwent pathological examination and 23 of them had the specific pathological changes of Alport syndrome. In 55 cases, 36 (65.4%) were diagnosed as X-linked Alport syndrome, 5(9.1%) were diagnosed as autosomal recessive Alport syndrome, 10(18.2%) were diagnosed as autosomal dominate Alport syndrome, and 4(7.3%) were diagnosed as digenic Alport syndrome. Missense mutations in COL4A genes accounted for 62.5%, 67.5% of missense mutations resulted in glycine substitution. There were statistical significances in proteinuria degree and hearing loss between male and female patients with XLAS (P < 0.05) as well as statistical significance in the degree of proteinuria between autosomal recessive Alport syndrome and autosomal dominate Alport syndrome (P=0.044), and there was critical statistical significance in the age of onset. There was statistical significance in hearing loss between children with renal impairment and children with normal renal function (P=0.001).  Conclusions  Most of the pathogenic variants in COL4A genes that cause Alport syndrome result in glycine substitutions. The degree of proteinuria and hearing loss of males with XLAS were greater than those of females. The degree of proteinuria in autosomal recessive Alport syndrome was greater than that of children with autosomal dominate Alport syndrome, and the age of onset was earlier than that of autosomal dominate Alport syndrome. Renal manifestation was more severe in children with hearing loss. The early clinical manifestations of Alport syndrome are diverse and pathological manifestations may be atypical. The application of next-generation sequencing can reduce misdiagnosises of Alport syndrome.

Pathogenicity evaluation and splicing correction of COL4A5 splice mutation in X-linked Alport syndrome / 中华肾脏病杂志

Objective:To analyze the splicing mutation site of COL4A5 gene in a family with X-linked dominant Alport syndrome and explore the possibility of exon specific U1 small nuclear RNA (snRNA) gene therapy. Methods:The clinical data of the proband and family members of Alport syndrome were collected, and the gene mutations in the whole exon of a series of nephropathy genes in the proband were detected by high-throughput sequencing. The splice site changes and pathogenicity caused by COL4A5 c.546+5G>A mutation were analyzed by online software. Minigene experiment was used to verify and analyze the effect of COL4A5 gene mutation site c.546+5G>A in the proband of Alport syndrome family, and transient transfection and introduction of modified U1 snRNA to correct splicing mutation. Results:The results of gene sequencing showed that there was a hemizygous variation of COL4A5 gene in the proband and his half brother, and the variation site was c.546+5G>A. The results of online software for analyzing the pathogenicity of splice variation showed that the original donor splicing site could not be detected after mutation, suggesting that there was a great possibility of affecting splicing. The abnormal splicing mode of COL4A5 gene with c.546+5G>A mutation—deletion of exon 9 was verified by hybridized small gene detection. The abnormal splicing mutation could be partially corrected by the modified U1 snRNA. The correction ratios of ExSpeU1 (MT), ExSpeU1(E9+1), ExSpeU1(E9+9) and ExSpeU1(E9+11) to exon 9 deletion caused by c.546+5G>A were 0, 43.81%, 52.09% and 48.12%, respectively. Conclusions:The pathogenicity of the new splicing mutation of COL4A5 is verified, and the modified U1 snRNA can partially correct the abnormal splicing.

Analysis and literature review of COL4A5 mutation mosaicism in male patients with X-linked Alport syndrome / 中华肾脏病杂志

Objective:To report four male COL4A5 mutation mosaicism patients with X-linked Alport syndrome, and to provide evidence for diagnosis, genetic counseling, and reproduction in the respective families and improve our knowledge of mosaicism in Alport syndrome. Methods:Suspected male mosaic patients for COL4A5 who met the following criteria: clinical diagnosis of Alport syndrome, harbored COL4A5 mutations detected using next generation sequencing or Sanger sequencing, heterozygosity for the mutant and normal COL4A5 alleles in the DNA demonstrated by Sanger sequencing, registered in the on-line registry of hereditary kidney diseases, and admitted to Peking University First Hospital during the period of April 2018 to April 2019 were enrolled. Clinical data and karyotypes were retrospectively analyzed. Genetic DNA isolated from multiple tissues was analyzed for COL4A5 gene mutations by using PCR and Sanger sequencing. Related literatures published in PubMed, CNKI and Wanfang databases were reviewed. Results:Four COL4A5 somatic and germline mosaic male patients with Alport syndrome were included in the study. Patient 1 was characterized by hematuria and proteinuria. His karyotype of peripheral blood was normal. COL4A5 c.3455-1G>A mosaicism was detected in multiple tissues (peripheral blood, saliva and urine). Patient 2 presented with hematuria and microalbuminuria. His karyotype of peripheral blood was normal. COL4A5 c.4994+1G>A mosaicism was detected in multiple tissues (peripheral blood, saliva and skin fibroblasts). Patients 3 showed hematuria without proteinuria. COL4A5 c.3535G>A mosaicism was found in genomic DNA of peripheral blood and hair. Laboratory and physical examinations of patient 4 showed hematuria and normal renal function, without proteinuria, megasoma or small testes. COL4A5 c.3106G>A mosaicism was detected in genomic DNA of skin fibroblasts. Although without karyotype analysis due to unavailable specimens, 47,XXY or 46,XY/47,XXY mosaicism was not considered according to the reproductive history and lack of clinical manifestations of megasoma and small testes in patients 3 and 4. Renal disease in 8 published male cases with mosaicism for COL4A5 was affected by mutant allelic fractions and genotype. Conclusions:Compared with hemizygous males with X-linked Alport syndrome, the renal phenotype of mosaic males was milder, and associated with mutant allelic fractions and mutation type.

Clinical characteristics and gene analysis of a family with autosomal dominant Alport syndrome with the onset of nephrotic syndrome / 中华实用儿科临床杂志

The clinical characteristics, mutation analysis results, and family tree of a patient with autosomal dominant Alport syndrome (ADAS), who had nephrotic syndrome as the first manifestation were examined.The proband was a 11-month-old girl who presented with nephrotic syndromes and gross hematuria.During the treatment course, the patient had steroid resistance and a poor response to Cyclosporine and Cyclophosphamide pulse therapy.Renal biopsy was performed 2 years after disease onset.Under the light microscopy, glomerular segmental mesangio-proliferative lesions were observed.The staining of type Ⅳ collagen showed the loss of the α3 chain in the glomerular basement membrane (GBM) and tubular basement membrane, and α5 chain loss in GBM.Electron microscopy showed uneven thickness of GBM, with obviously delaminated and tearing dense basement membrane (BM) layer, showing a typical lace-like change.The segmental BM was loosened and widened.Her father did not develop microscopic hematuria until 10 years later, while her grandmother had asymptomatic hematuria and proteinuria when the proband was diagnosed.A new mutation in the COL4A4 gene was found in the proband, namely c. 1715delG (p.G572Vfs * 81). Her father and grandmother carried the same mutation, but her mother and sister did not have.The clinical manifestation of ADAS is clinically heterogeneous and its incidence may be higher than what we have expected.

Research progress of ocular manifestations and pathological mechanisms in Alport syndrome / 国际眼科杂志(Guoji Yanke Zazhi)

@#Alport syndrome(AS)is a genetic disease characterized by abnormal basement membrane structure of the kidneys, ears and eyes. The incidence of the disease is 1:5000 approximately. The report on ocular manifestations is relatively scarce, however, it is of great value to diagnosis of the disease. The ocular tissue histopathological analysis provides an effective method to uncover the pathological mechanisms of AS. Besides, it is good for understanding and treatment of AS.

Clinical and genetic diagnosis of a pedigree affected with autosomal recessive Alport syndrome / 中华医学遗传学杂志

Objective@#To explore the genetic basis of a child with chronic kidney disease featuring renal shrinkage and creatinine increase.@*Methods@#Peripheral venous blood samples were taken from the child, his brother and two parents and subjected to whole exome sequencing. Suspected mutations were verified by Sanger sequencing. Bioinformatic analysis was carried out to predict the influence of mutations on the structure and function of the protein product.@*Results@#High-throughput and Sanger sequencing revealed that the child has carried compound heterozygous mutations of the COL4A4 gene, namely c. 4550T>G in exon 47 (inherited from his mother) and c. 199C>T in exon 5 (inherited from his father). Neither mutation was reported previously. Bioinformatic analysis showed that both mutations have located in highly conserved regions. The same mutations were not found in his brother.@*Conclusion@#The compound heterozygous c. 4550T>G and c. 199C>T mutations probably underlie the disease in this child. The findings have enriched the mutation spectrum of the COL4A4 gene.

A novel splicing mutation identified in a Chinese family with Alport syndrome and analysis of its pathogenicity / 医学研究生学报

Objective The purpose of this study was to identify a pathogenic variant in a Chinese family with Alport syndrome and analyze the pathogenicity of the variant. Methods Using targeted region capture and high-throughput sequencing technology, we identified the genetic variant of the proband with Alport syndrome, verified the variant in the family members by Sanger sequencing, and analyzed its influence on the pre-mRNA splicing process by in vitro minigene assay. Results A heterozygous variant c.2767G>T (p.Gly923Cys) was identified as a novel variant in exon 32 of the COL4A5 gene in the proband, which was confirmed by Sanger sequencing to be cosegregated with disease in the family. The minigene assay demonstrated that the c.2767G>T variant induced deletion of exon 32 of the COL4A5 gene. Conclusion A novel COL4A5 mutation was identified by targeted region capture and high-throughput sequencing, which has enriched the gene mutation spectrum of Alport syndrome. The exonic mutation c.2767G>T confirmed to be a splicing mutation by in vitro minigene assay, which may lead to a deeper insight into the molecular pathogenesis of Alport syndrome.

De novo mutations in COL4A5 identified by whole exome sequencing in 2 girls with Alport syndrome in Korea / 소아과

Alport syndrome (ATS) is an inherited glomerular disease caused by mutations in one of the type IV collagen novel chains (α3, α4, and α5). ATS is characterized by persistent microscopic hematuria that starts during infancy, eventually leading to either progressive nephritis or end-stage renal disease. There are 3 known genetic forms of ATS, namely X-linked ATS, autosomal recessive ATS, and autosomal dominant ATS. About 80% of patients with ATS have X-linked ATS, which is caused by mutations in the type IV collagen α5 chain gene, COL4A5. Although an 80% mutation detection rate is observed in men with X-linked ATS, some difficulties do exist in the genetic diagnosis of ATS. Most mutations are point mutations without hotspots in the COL4A3, COL4A4, and COL4A5 genes. Further, there are insufficient data on the detection of COL4A3 and COL4A4 mutations for their comparison between patients with autosomal recessive or dominant ATS. Therefore, diagnosis of ATS in female patients with no apparent family history can be challenging. Therefore, in this study, we used whole-exome sequencing (WES) to identify mutations in type IV collagen in 2 girls with glomerular basement membrane structural changes suspected to be associated with ATS; these patients had no relevant family history. Our results revealed de novo c.4688G>A (p.Arg1563Gln) and c.2714G>A (p.Gly905Asp) mutations in COL4A5. Therefore, we suggest that WES is an effective approach to obtain genetic information in ATS, particularly in female patients without a relevant family history, to detect unexpected DNA variations.

Clinical analysis of angiotensin-converting enzyme inhibitor in treatment of Alport syndrome / 中华实用儿科临床杂志

Objective To investigate the clinical efficacy and safety of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) in treatment of children with Alport syndrome (AS).Methods A total of 22 children with AS in Department of Pediatrics,Guangzhou First People's Hospital and Department of Pediatrics,Shenzhen People's Hospital between January 2013 and December 2017 were selected.But four children were not included in this study since they did not take medication regularly,and the other 18 cases were included in this study.All the 18 children were initially treated with ACEI.The observation time was from 1 to 5 years.If the symptoms were not effectively controlled,treatment plan would be changed to ACEI combined with ARB treatment.The observation time was from 1 to 3 years.The clinical data and laboratory examination results [including 24-hour urine protein (mg/24 h),urine red blood cell count,plasma albumin (Alb),urea nitrogen (BUN),serum creatinine (Scr),total cholesterol (TC)] were collected for retrospective analysis.Results Eighteen patients started their treatment with ACEI inhibitors (Fosinopril).Within 2 years of treatment,the urinary protein and urinary red blood cells in the children decreased to 47.7％ and 41.3％,respectively,and the differences were all statistically significant (all P ＜ 0.05),and the renal function was stable within the normal range.Two years later,7 patients had elevation of urinary protein and urinary erythrocyte elevations and decrease of renal function,and they were treated with ACEI and ARB (Losartan).The other children had no significant change in urine protein and urine red blood cells in the 3 rd,4th,and 5th year,and their renal function was stable.After ACEI treatment alone for 5 years,urinary protein was 47.8％ lower than before treatment,and the difference was statistically significant (P ＜ 0.05);urinary red blood cells decreased to 32.0％ compared with before treatment,and the difference was statistically significant (P ＜ 0.05).Seven patients with ACEI alone had poor efficacy,after the treatment with ACEI combined with ARB,the urinary protein and urine red blood cells were lower in the first year and the renal function improved.There was no significant change in urinary protein and urine red blood cells in the 2nd and 3rd year,and renal function was stable.After ACEI combined with ARB treatment for 3 years,urinary protein decreased to 42.3％ before treatment,and the difference was statistically significant (P ＜ 0.05),and urinary red blood cells decreased to 46.9％ compared with before treatment,and the difference was statistically significant(P ＜ 0.05).Conclusions ACEI treatment of children with AS can reduce urine protein and help delay renal failure.For children with poor efficacy of ACEI treatment,ACEI combined with ARB may have a certain effect.ARB can be used as an adjunctive treatment for patients with AS who have a poor response to ACEI alone.

Advances in Alport syndrome / 国际儿科学杂志

Alport syndrome is a rare genetic disorder of specialized basement membranes in the kidney,ear,and eye.Eighty percent of patients have X-linked disease caused by mutations in the COL4A5 gene;autosomal forms of the other Alport syndrome are caused by mutations in COI4A3 and COL4A4 genes.These mutations result in progressive irregular thickening,thinning,and splitting of the GBM,leading to end stage renal failure.During the past two decades,research into this rare disease has focused on the effects of mutations in collagen type Ⅳ α chains and the role of changes in podocytes and the glomerular basement membrane that lead to early kidney fibrosis.In this review,we discuss the latest basic and clinical research on Alport syndrome,focusing on the roles of podocyte pathology and the extracellular matrix.