Temporal retinal thinning might be an early diagnostic indicator in male pediatric X-linked Alport syndrome

AIM: To evaluate temporal retinal thinning changes in retinal layers using spectral-domain optical coherence tomography(SD-OCT) in pediatric X-linked Alport syndrome(XLAS) patients.METHODS: A retrospective case-control study. SDOCT scans of pediatric patients diagnosed with XLAS and age-and sex-matched healthy control participants were reviewed. Automated segmentation of SD-OCT scans was induced to analyze the retinal thickness(RT) of different layers. The temporal thinning index(TTI) was calculated for each layer and compared between the patients and the control group.RESULTS: Forty-three pediatric XLAS patients and 60 healthy controls were included. Temporal retinal thinning was present in 33 patients(76.74%), while 28 patients(65.11%) had severe pathological temporal retinal thinning and 5 patients(11.63%) had moderate thinning. The temporal inner sector RT(P<0.0001), the temporal outer sector RT(P<0.0001), and the nasal outer sector RT(P=0.0211) were significantly thinner in the XLAS male patients. The TTI of the total retina was significantly higher in the XLAS group than in the control group(P<0.0001). The TTI of the inner retina layers(P<0.0001), ganglion cell layer(P<0.0001), inner plexiform layer(P<0.0001), inner nuclear layer(P<0.0001), and outer nuclear layer(P<0.0001) were significantly higher in the XLAS group. The central RT of the XLAS group was significantly thinner than that of the control group(P<0.0001).CONCLUSION: Temporal retinal thinning appears early in XLAS patients, especially in male patients. The thinningis mainly caused by structural abnormalities of the inner retina. This suggests that temporal retinal thinning could be helpful for the early diagnosis and follow-up of XLAS with noninvasive SD-OCT examination.

Novel COL4A3 synonymous mutation causes Alport syndrome coexistent with immunoglobulin A nephropathy in a woman:A case report

BACKGROUND Alport syndrome(AS)is an inherited disease of the glomerular basement membrane caused by mutations in genes encodingα3,α4,orα5 chains of type IV collagen.It manifests with hematuria or proteinuria,which is often accompanied by hearing impairments and ocular abnormalities.Histopathologically,AS shows mesangial proliferation and sometimes incidental immunoglobulin A(IgA)deposition.Hematuria or proteinuria is also a common presentation in patients with IgA nephropathy that makes it difficult to differentially diagnose AS and IgA nephropathy solely based on these clinical and pathological features.CASE SUMMARY Herein,we present the case of a 59-year-old female patient who was admitted to our hospital with persistent microscopic hematuria and occasional proteinuria that had lasted for>2 years.This patient had a familial history of renal disease and was diagnosed with autosomal dominant AS(ADAS)and IgA nephropathy based on the findings of renal biopsy as well as genetic testing performed using whole-exome sequencing,which suggested that the patient carried a novel heterozygous variation(c.888G>A:p.Gln296Gln)in the COL4A3 gene that enriches the mutation spectrum of ADAS.The proband received an angiotensin receptor blocker therapy after a definitive diagnosis was established.After one year of therapy,a significant reduction in proteinuria was observed.The number of microscopic red blood cells per high-power field decreased to one-quarter of the baseline levels.Renal function also maintained well during the follow-up.CONCLUSION Our case highlights the significance of performing kidney biopsy and genetic testing in the diagnosis of AS and familial IgA nephropathy.

CNKSR2 mutation causes the X-linked epilepsy-aphasia syndrome:A case report and review of literature

The mutation in CNKSR2 leads to a broad spectrum of phenotypic variability and manifests as an X-linked intellectual disability. However, we reported that the male patient in this study not only had intellectual disability but also epileptic seizures. In addition, there were progressive language impairment, attention deficit hype-ractivity disorder and autism. Electroencephalograms showed continuous spike-and-wave during sleep. Genetic testing revealed a de novo mutation of the CNKSR2 gene(c.2185C >T, p.Arg729Ter) in the child that was not detected in the parents. Therefore, the child was diagnosed with X-linked epilepsy aphasia syndrome. Deletion of the CNKSR2 gene has been rarely reported in epilepsy aphasia syndrome, but no de novo mutation has been found in this gene. This report not only adds to the spectrum of epilepsy aphasia syndrome but also helps clinicians in diagnosis and genetic counseling.

X-linked recessive Kallmann syndrome:A case report

BACKGROUND Kallmann syndrome(KS),also known as hypogonadotropic hypogonadism(HH)or olfactory-gonadal dysplasia,is a genetic condition in which the primary symptom is a failure to begin puberty or a failure to fully complete it.It occurs in both males and females and has the additional symptoms of hypogonadism and almost invariably infertility.The condition has a low prevalence that is estimated to be 1 in 4000 for male HH cases overall and 1:50000 for KS.It is three to five times more common in males than females.Whether this is a true sex imbalance or a reflection of how difficult KS/HH is to diagnose correctly in males vs females has yet to be fully established.CASE SUMMARY This article reports a 26-year-old male presenting with delayed puberty.The synthetic decapeptide luteinizing hormone-releasing hormone stimulation test showed that the secretion levels of follicle-stimulating hormone and luteinizing hormone were delayed.The eigengenes commonly associated with idiopathic HH(IHH)were screened,and an X-linked recessive(KAL-1)mutation was found.His gonadotropin and testosterone levels increased significantly after pulsatile gonadotropin-releasing hormone(GnRH)subcutaneous therapy by pump.A relevant literature review on the recent advances in the diagnosis and treatment of KS and genetic counseling was conducted.CONCLUSION KS is caused by a KAL-1 mutation that follows an X-linked recessive inheritance pattern.Pulsatile GnRH subcutaneous therapy by pump was effective in this patient.

Early-onset refractory diarrhea due to immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome associated with a novel mutation in the FOXP3 gene: A case report

BACKGROUND Immune dysregulation,polyendocrinopthy,enteropathy,X-linked(IPEX)syndrome is a rare X-linked recessive disease caused by mutations in the forkhead box protein 3(FOXP3)gene,which is a master transcriptional regulator for the development and function of CD4+CD25+regulatory T(Treg)cells.The dysfunction of these cells leads to multiple system autoimmune diseases.We present a case of IPEX due to a mutation not reported in the literature before.CASE SUMMARY We report a male patient with IPEX syndrome who presented with refractory diarrhea and malabsorption leading to failure to thrive,as well as with hypothyroidism and nephrotic syndrome.Laboratory investigation showed increased total IgE and Treg cells,decreased free triiodothyronine(FT3)and free thyroxine(FT4),and proteinuria.Multiple dietary and supportive treatments were introduced but did not improve the diarrhea during his hospital stay.Ultimately,whole exome sequencing revealed that the patient was hemizygous for the exon 5,c.542G>A(p.Ser181Asn)mutation of the FOXP3 gene,which has not been previously reported.The patient remains on prednisone and euthyrox while awaiting hematopoietic stem cell transplantation at the time of the compilation of this case report.CONCLUSION We report a novel FOXP3 gene mutation involved in IPEX.A high level of suspicion should be maintained in an early-onset refractory diarrhea patient.

Identification of a novel COL4A5 mutation in the proband initially diagnosed as Ig AN from a Chinese family with X-linked Alport syndrome

Alport syndrome(AS) is a hereditary progressive nephropathy characterized by hematuria, ultrastructural lesions of the glomerular basement membrane, ocular lesions and sensorineural hearing loss. Germline mutations of COL4 A5 are associated with X-linked AS with an extreme phenotypic heterogeneity. Here, we investigated a Chinese family with Alport syndrome. The proband was a 9-year-old boy with hematuria and proteinuria. Based on the test results of renal biopsy and immunofluorescence,the proband was initially diagnosed as Ig A nephropathy and the treatment was recommended accordingly. Meanwhile, we found that the treatment outcome was poor. Therefore, for proper clinical diagnosis and appropriate treatment, targeted exome-based next-generation sequencing has been undertaken. We identified a novel hemizygous single nucleotide deletion c.1902 del A in COL4 A5 gene. Segregation analysis identified that this novel mutation is co-segregated among the affected family members but absent in unaffected family members. The clinical diagnosis of the proband was revised as AS accompanied by Ig A nephropathy,which has been rarely reported. Our findings demonstrated the significance of the application of Genetic screening, expanded the mutation spectrum of COL4 A5 associated AS patients with atypical renal phenotypes and provided a good lesson to be learned from our detour during the diagnosis.

Ocular manifestations of Alport syndrome

AIMTo analyze the clinical manifestation of Alport syndrome, especially the ocular features.

X-linked Charcot-Marie-Tooth disease after SARS-CoV-2 vaccination mimicked stroke-like episodes: A case report

BACKGROUND Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) vaccinations have been administered worldwide, with occasional reports of associated neurological complications. Specifically, the impact of vaccinations on individuals with Xlinked Charcot-Marie-Tooth disease type 1(CMTX1) is unclear. Patients with CMTX1 can have stroke-like episodes with posterior reversible encephalopathy syndrome on magnetic resonance imaging(MRI), although this is rare.CASE SUMMARY A 39-year-old man was admitted with episodic aphasia and dysphagia for 2 d. He received SARS-CoV-2 vaccination 39 d before admission. Physical examination showed pes cavus and reduced tendon reflexes. Brain MRI showed bilateral, symmetrical, restricted diffusion with T2 hyperintensities in the cerebral hemispheres. Nerve conduction studies revealed peripheral nerve damage. He was diagnosed with Charcot-Marie-Tooth disease, and a hemizygous mutation in the GJB1 gene on the X chromosome, known to be pathogenic for CMTX1, was identified. Initially, we suspected transient ischemic attack or demyelinating leukoencephalopathy. We initiated treatment with antithrombotic therapy and immunotherapy. At 1.5 mo after discharge, brain MRI showed complete resolution of lesions, with no recurrence.CONCLUSION SARS-CoV-2 vaccination could be a predisposing factor for CMTX1 and trigger a sudden presentation.

Alport syndrome combined with lupus nephritis in a Chinese family:A case report

BACKGROUND Alport syndrome(ATS)is a rare hereditary disease caused by mutations in genes such as COL4A3,COL4A4,and COL4A5.ATS involves a spectrum of phenotypes ranging from isolated hematuria that is nonprogressive to progressive renal disease with extrarenal abnormalities.Although ATS can be combined with other diseases or syndromes,ATS combined with lupus nephritis has not been reported before.CASE SUMMARY A Chinese family with ATS was recruited for the current study.Clinical characteristics(including findings from renal biopsy)of ATS patients were collected from medical records,and potential causative genes were explored by whole-exome sequencing.A heterozygous substitution in intron 22 of COL4A3(NM_000091 c.2657-1G>A)was found in the patients,which was further confirmed by quantitative polymerase chain reaction.CONCLUSION Heterozygous substitution of a COL4A3 gene splice site was identified by wholeexome sequencing,revealing the molecular pathogenic basis of this disorder.In general,identification of pathogenic genes can help to fully understand the molecular mechanism of disease and facilitate precise treatment.

Keratoconus in a patient with Alport syndrome: A case report

BACKGROUND Known ocular manifestations of Alport syndrome include features such as anterior lenticonus and fleck retinopathy. Reports of keratoconus in such patients are limited. We report tomographic findings consistent with keratoconus in a patient with Alport syndrome.CASE SUMMARY A 52-year-old female was referred to our ophthalmology clinic with decreased vision and increased tearing. She was diagnosed with stage Ⅲ Alport syndrome two years prior. Upon examination she was found to have average keratometries of 48D bilaterally with tomographic evidence of keratoconus.CONCLUSION Although a rare presentation, concurrent Alport syndrome and keratoconus should be considered when reviewing the ocular health of Alport syndrome patients and appropriate management steps should be taken upon the diagnosis.

Searching for a treatment for Alport syndrome using mouse models

Alport syndrome(AS) is a hereditary nephritis caused by mutations in COL4A3,COL4A4 or COL4A5 encoding the type IV collagen α3,α4,and α5 chains,which are major components of the glomerular basement membrane.About 20 years have passed since COL4A3,COL4A4,and COL4A5 were identified and the first Alport mouse model was developed using a knockout approach.The phenotype of Alport mice is similar to that of Alport patients,including characteristic thickening and splitting of the glomerular basement membrane.Alport mice have been widely used to study the pathogenesis of AS and to develop effective therapies.In this review,the newer therapies for AS,such as pharmacological interventions,genetic approaches and stem cell therapies,are discussed.Although some stem cel therapies have been demonstrated to slow the rena disease progression in Alport mice,these therapies demand continual refinement as research advances.In terms of the pharmacological drugs,angiotensin-converting enzyme inhibitors have been shown to be effective in Alport mice.Novel therapies that can provide a better outcome or lead to a cure are still awaited.

Speech,language,and hearing function in twins with Alport syndrome:A seven-year retrospective case report

Alport syndrome is an X-linked syndrome that results in nephritis, renal failure, sensorineural hearing loss, and eye deficits. As a result of sensorineural hearing loss, these individuals are likely to experience difficulties in the area of speech and language. While studies in the past have examined the speech and language characteristics of children with syndromic sensorineural hearing loss, to our knowledge there are no previous studies to have documented the speech and language characteristics of these children on a long-term basis. The current study addresses this limitation by reporting speech, language, hearing, and function of twin brothers with X-linked Alport syndrome across a seven-year period.Information was collected by examining the medical records of the participants as well as through a verbal interview with the participants' guardian. Results revealed that the participants' hearing abilities gradually deteriorated over the seven-year period which affected their speech and language development as well. The kidney function tests revealed significant presence of hematuria(blood in the urine) as well as proteinuria(protein in the urine) suggesting chronic kidney dysfunction. This longitudinal study demonstrates the functional relationship between the kidneys and the cochlea, although they appear to be independent of one another. As individuals with Alport syndrome exhibit systemic complications, interdisciplinary collaboration is essential among health care providers including audiologists, speech-language pathologists,nephrologists, and ophthalmologist to promote evidence-based practice.

Optic Disc Drusen in a Child Diagnosed with Alport Syndrome—Case Report

Optic disc drusen are eye abnormalities characterised by calcific degeneration affecting some axons of the optic nerve. Alport syndrome is a collagen IV related nephropathy with well-described pathognomonic ocular features. We present the case of a child who following series of investigations was found to have bilateral optic disc drusen, and eventually a further diagnosis of Alport syndrome confirmed. Literature is clear on the underlined aetiology responsible for both renal and extra renal abnormalities of Alport syndrome, which is not related to development of optic disc drusen. The case described makes it pertinent that not only the associated eye signs of Alport syndrome are monitored, but also early detection of other possible co-existing diseases that may influence outcomes.

Immunofluorescence study of type Ⅳ collagen α chains in epidermal base-ment membrane : application in diagnosis of X-linked Alport syndrome

Objective To detect the distribution of α5(Ⅳ) chain of collagen on the glomerular basement membrane (GBM) and epidermal basement membrane (EBM) in the Chinese Alport syndrome (AS) kindreds and to develop a simple diagnostic alternative method to electronic microscopy for diagnosis of AS. Methods Four male patients from 4 unrelated families manifested with hematuria, sensorineural hearing loss and had distinct family history. All patients had the characteristic AS pathologic changes by electron microscopy on their renal biopsy tissues. Three normal skin samples and 2 normal kidney samples were used as normal controls. Monoclonal antibody based IF test was performed to examine the α5(Ⅳ)NC1 domain in EBM of normal controls, X linked AS patients and their parents, and in GBM of normal controls and AS patients. Results In normal controls as well as the patients' fathers, all the monoclonal antibodies used in EBM and GBM staining showed positive reactions along basement membranes in a linear pattern. Characteristically, in AS patients there were negative reactions to monoclonal antibodies anti α5(Ⅳ)NC1 domain in EBM and anti α3 5(Ⅳ)NC1 domains in GBM. In patients' mothers, α5(Ⅳ) chain was distributed segmentally in EBM. Conclusion The staining of α5(Ⅳ) NC1 domain in EBM by IF can be used to diagnose patients and screen defect gene carriers of X linked AS.

母女同患紫癜性肾炎合并Alport综合征1家系报道

过敏性紫癜(henoch-schonlein purpura,HSP)又称IgA血管炎,是儿童常见的系统性血管炎疾病之一,本病多为自限性疾病、预后相对较好。HSP累及肾脏即为紫癜性肾炎(henoch schonlein purpura nephritis,HSPN),又称IgA血管炎肾炎,是儿科临床肾脏专业常见的继发性肾小球疾病之一[1-4]。

肾组织石蜡切片Ⅳ型胶原α链免疫组织化学染色在诊断Alport综合征中的应用

目的对Alport综合征(AS)患者肾脏穿刺组织进行石蜡切片Ⅳ型胶原α链免疫组织化学检测,探讨其临床应用价值。方法选取2018年11月至2022年7月浙江大学医学院附属第一医院肾脏病中心确诊的10例AS患者(AS病例组)、10例心脏死亡器官捐献者(DCD)供肾及10例确诊为免疫球蛋白A肾病患者(对照组)的肾组织进行石蜡切片Ⅳ型胶原α1、α3、α5链全自动免疫组织化学染色,将其与冰冻切片免疫荧光染色结果进行比较。将对照组肾组织石蜡切片分别采用多种方法进行抗原修复,比较修复效果。结果对照组肾组织2种染色方法Ⅳ型胶原α1、α3、α5链染色在肾小球基底膜(GBM)中均为连续线状阳性表达。AS病例组肾组织2种染色方法Ⅳ型胶原α1链染色在GBM均呈连续线状阳性表达,α3、α5链染色在GBM为阴性或节段弱阳性表达。2种染色方法染色结果具有较高的一致性(Kappa=0.615,P=0.035)。结论石蜡切片全自动免疫组织化学检测Ⅳ型胶原α1、α3和α5能较好地用于AS的诊断,为AS的诊断和研究提供了一种可靠的技术手段。

COL4A4基因新突变致常染色体显性遗传Alport综合征一例并文献复习

Alport综合征(AS)是慢性肾脏病和终末期肾脏病(ESRD)的重要病因之一,是继常染色体显性遗传性多囊肾后第二常见的遗传性肾脏疾病。常染色体显性遗传是AS中非常少见的遗传方式,既往报道常染色体显性遗传AS(ADAS)患者进展至ESRD年龄较晚。本文报道1例因发现尿检异常4年于2019-09-05就诊于河南中医药大学第一附属医院儿科肾脏病区确诊为ADAS患者的临床资料及基因检测结果并复习相关文献。报道了COL4A4基因新发变异c.3506-3528del(p.G1169Efs*13)所致ADAS家系(该家系中1名成员在31岁时已进展至ESRD)的临床、肾脏病理及基因突变情况,并总结了中国ADAS的文献报道,对该病的基因和临床表型、预后之间的关系做了较全面地分析。由于ADAS发病率低,此家系报道扩展了AS的基因突变谱,有助于提高临床医生对罕见发病的ADAS的认识和及时诊治。

儿童Alport综合征COL4A5基因型及临床特点分析

目的探讨儿童Alport综合征(Alportsyndrome,AS)致病基因COL4A5基因型与临床表型的特点。方法回顾性分析19例存在COL4A5基因突变的AS患儿的基因检测结果和临床资料。结果19例COL4A5基因突变导致的AS患儿中,1例(5%)存在COL4A5基因新突变位点c.3372A>G(p.P1124=),其表现为AS合并IgA血管炎肾炎;3例(16%)存在COL4A5基因大片段缺失,其中2例(例7为新突变位点:loss51-53)起病即存在肉眼血尿和蛋白尿,1例(例13,存在新突变位点:loss3-53)仅有镜下血尿;其余15例(79%)患儿均为AS的常见临床表型,其中7例存在COL4A5基因新突变位点。3例(16%)患儿合并COL4A4基因突变,1例(5%)合并COL4A3基因突变,在这些双基因突变患儿中有2例起病即为肉眼血尿合并蛋白尿。结论该研究拓展了AS致病基因COL4A5的基因型和表型谱;发生COL4A5基因大片段缺失突变或COL4A5合并COL4A3或COL4A4的双基因突变患儿的临床表现更严重。

以COL4A5基因突变为主Alport综合征临床分析

目的对COL4A5基因突变的X连锁遗传的Alport综合征(X-linked Alport syndrome,XLAS)患儿的临床表型及基因突变类型进行分析,探讨XLAS患儿与肾病综合征肾炎型的关系。方法纳入2016年4月至2023年4月期间在医院经二代测序发现COL4A5基因突变最终确诊为Alport综合征的32例患儿,回顾性分析其临床病理特征与基因突变特点。结果XLAS患儿平均起病年龄(3.68±2.07)岁,平均确诊年龄(6.56±2.95)岁,以孤立性血尿起病12例(37.5%),以血尿和蛋白尿起病8例(25%),以肾病综合征肾炎型起病12例(37.5%),患儿家族史阳性有11例(34.4%),眼部病变3例(9.37%),耳部病变6例(18.75%),后期随访发现7例(21.87%)患儿已发展为慢性肾脏病(chronic kidney disease,CKD)。21例患儿行肾脏组织穿刺活检,电镜表现为基底膜变薄(弥漫性或节段性)13例(61.9%),基底膜厚薄不均8例(38.09%);光镜:局灶节段肾小球硬化(FSGS)2例(9.52%),系膜增生性肾小球肾炎(Ms PGN)11例(52.38%),微小病变(MCD)8例(38.09%)。基因突变类型分为错义突变12例(37.5%)、剪切位点突9例(28.12%)、无义突变6例(18.75%)、缺失突变3例(9.37%)、移码突变2例(6.25%)。遗传突变22例(68.75%);自发突变10例(27.02%)。结论XLAS患儿在疾病早期临床表现和病理特征均不典型,进展缓慢,部分患儿早期易误诊为肾病综合征肾炎型,对于疑似本病尽早完善基因检测,合理药物选择,科学预测预后。

Alport综合征治疗进展

Alport综合征(AS)是引起肾衰竭的第二大常见单基因病,导致患者在生命早期即面临终末期肾病(ESKD)的风险。目前AS尚无病因治疗方法,也无明确可防止晚期肾衰竭的治疗选择。虽然血管紧张素转换酶抑制剂(ACEIs)的临床应用显著延缓了ESKD的发生,并且以时间依赖的方式提高了患者的预期寿命,但仍难以改变ESKD甚至死亡的临床结局。这反映了AS病理学的复杂性,单一的肾素血管紧张素-醛固酮系统阻滞剂不能够完全阻断疾病进展,需要与ACEIs具有不同作用方式的新型治疗选择。迄今为止,国际上已经开展了较多的相关研究以期为AS的临床治疗提供新的方法。文章主要对AS潜在治疗方案的最新研究进展进行综述。