OBJECTIVETo analyze the clinical features and gene mutation of Chinese children with Alport syndrome(AS).

METHODFrom May 2011 to May 2014, clinical and pathological information gathered from 25 patients was retrospectively analyzed. COL4A5, COL4A4 and COL4A3 genes were analyzed using next-generation sequencing in these patients, and gene mutations of related family members were identified by Sanger method.

RESULTOf these 25 cases, 19(76%) had X-linked Alport syndromes (XL-AS), 6 had autosomal recessive Alport syndromes (AR-AS). Twenty five patients had an onset of hematuria and proteinuria and in 8 cases the disease was induced by upper respiratory tract infections. Hearing loss was present in 2 of 25 (8%) cases and ocular lesions in 1 of 25 (4%). Renal pathology showed that 16 of them had minimal change disease (MCD), 8 mesangial proliferative glomerulonephritis (MsPNG), 1 focal segmental glomerulo-sclerosis (FSGS). Extensive lamination and split of glomerular basement membrane (GBM) dense layers were found in 2 (8%) of 25 patients. Twenty one of 25 patients (84%) showed abnormal renal α-chain distribution. COL4A5, COL4A4 and COL4A3 genes of 25 patients (23 families) were analyzed and 24 pathogenic mutations were identified: 18 in COL4A5, 1 in COL4A3 and 5 in COL4A4. It was observed that 13 patients inherited the mutation from the mother, 3 patients inherited from the father, 2 patients inherited 1 mutation from the mother and another mutation from the father, and 7 patients carried the novel mutations.

CONCLUSIONXL is the main inherited type in AS. Most of patients showed MCD and MsPNG in renal biopsy. This research examined 24 mutations and 16 mutations were not reported previously.

Child ; Deafness ; Genes, Recessive ; Genotype ; Hematuria ; Humans ; Kidney ; Mutation ; Nephritis, Hereditary ; genetics ; pathology ; Pedigree ; Phenotype

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.
Humans ; Nephritis, Hereditary/pathology* ; Hematuria/complications* ; Retrospective Studies ; Collagen Type IV/genetics* ; Genotype ; Mutation

OBJECTIVETo study the clinical and pathological features of Alport syndrome in children.

METHODSThe clinical and histopathological data of 10 hospitalized children with Alport syndrome from February 2007 to February 2009 were retrospectively reviewed.

RESULTSThere were 7 males and 3 females, with the age ranging from 2 years to 6 years and 7 months (mean 3 years and 2 months). Five of 10 cases had positive family history. X-linked dominant inheritance Alport syndrome was diagnosed in 8 cases, and autosomal recessive inheritance Alport syndrome in 2 cases. Recurrent gross hematuria was found in 5 cases, hematuria and proteinuria in 3 cases, massive proteinuria in 1 case, and nephritic syndrome in 1 case. Under the light microscope, 8 cases presented with mesangial proliferation glomerulonephritis, and 2 cases with focal segmental glomerulosclerosis. Immunofluorescence assay showed that all cases had IgM deposition in glomerulus. Only 1 case showed typical glomerular basement membrane (GBM) pathological changes. All cases showed abnormal alpha-chain distribution in renal collagen IV.

CONCLUSIONSThe children with Alport syndrome have diverse clinical manifestations. Characteristic histopathological presentations could not be found under a light microscope, mesangial proliferation glomerulonephritis is the dominant pathological change, and IgM deposition in glomerulus is common. The GBM pathological change in children is not common. Immunofluorescence assay of alpha-chain in collagen IV is needed for the diagnosis of Alport syndrome.

Child ; Child, Preschool ; Collagen Type IV ; genetics ; Female ; Humans ; Kidney ; pathology ; Male ; Nephritis, Hereditary ; diagnosis ; genetics ; pathology

Objective:To investigate long-term auditory changes and characteristics of Alport syndrome（AS） patients with different degrees of renal injury. Methods:Retrospectively analyzing clinical data of patients diagnosed AS from January 2007 to September 2022, including renal pathology, genetic detection and hearing examination. A long-term follow-up focusing on hearing and renal function was conducted. Results:This study included 70 AS patients, of which 33（25 males, 8 females, aged 3.4-27.8 years） were followed up, resulting in a loss rate of 52.9%.The follow-up period ranged from 1.1to 15.8 years, with 16 patients followed-up for over 10 years. During the follow-up, 10 patients presenting with hearing abnormalities at the time of diagnosis of AS had progressive hearing loss, and 3 patients with new hearing abnormalities were followed up, which appeared at 5-6 years of disease course. All of which were sensorineural deafness. While only 3 patients with hearing abnormalities among 13 patients received hearing aid intervention. Of these patients,7 developed end-stage renal disease（ESRD）, predominantly males （6/7）. The rate of long-term hearing loss was significantly different between ESRD group and non-ESRD group（P=0.013）. There was no correlation between the progression of renal disease and long-term hearing level（P>0.05）. kidney biopsies from 28 patients revealed varying degrees of podocyte lesion and uneven thickness of basement membrane. The severity of podocyte lesion was correlated with the rate of long-term hearing loss（P=0.048）, and there was no correlation with the severity of hearing loss（P>0.05）. Among 11 cases, theCOL4A5mutationwas most common （8 out of 11）, but there was no significant correlation between the mutation type and hearing phenotype（P>0.05）. Conclusion:AS patients exhibit progressive hearing loss with significant heterogeneity over the long-term.. THearing loss is more likely to occur 5-6 years into the disease course. Hearing abnormalities are closely related to renal disease status, kidney tissue pathology, and gene mutations, emphasizing the need for vigilant long-term hearing follow-up and early intervention.
Male ; Child ; Female ; Humans ; Nephritis, Hereditary/pathology* ; Retrospective Studies ; Kidney ; Deafness ; Hearing Loss/genetics* ; Kidney Failure, Chronic/pathology* ; Mutation

Alport syndrome is a hereditary, progressive disease characterized by progressive nephritis, sensorineural deafness, and ocular abnormalities, including anterior lenticonus. The ultrastructure of the lens capsule abnormalities in Alport syndrome is reported. Four anterior lens capsules from 31-year-old patient and 26-year-old patient with lenticonus who were affected by the Alport syndrome were obtained at capsulectomy. And all four anterior lens capsules were examined by transmission electron microscopy. The histopathologic findings showed that the thickness of the anterior lens capsules was decreased (4~13 micrometer) and that there were many vascular dehiscences localized at the inner part of the lens capsule. There were large numbers of capsular dehiscences containing fibrillar materials and vacuoles. The anterior capsules were clearly fragile in this disease, forming the basis for the progressive lenticonus and anterior polar cataract.
Adult ; Epithelial Cells/ultrastructure ; Humans ; Lens Capsule, Crystalline/*ultrastructure ; Lens Diseases/genetics/*pathology ; Lens Implantation, Intraocular ; Male ; Nephritis, Hereditary/genetics/*pathology ; Phacoemulsification

OBJECTIVETo explore the clinical and pathological features and the diagnosis of childhood Alport syndrome (AS).

METHODSA retrospective analysis was performed on clinical data of 91 children with AS.

RESULTSHematuria was observed in all 91 patients, of whom 86 were accompanied with proteinuria. Sixty-one children with X-Linked AS (XL-AS) had positive family history. Renal biopsy was performed on 82 children. Mild to moderate mesangial proliferation was observed in 74 cases. Small amounts of immune complexes deposits in the glomerular mesangial area were observed in 48 cases. Glomerular basement membrane (GBM) attenuation, thickening and layering were observed in 53 cases by electron microscopy (EM). In 63 cases receiving renal tissue type IV collagen α3 and α5 chain immunofluorescence detection, 58 were diagnosed with AS, including 53 cases of XL-AS and 5 cases of autosomal recessive AS. In 91 cases of AS, 58 were diagnosed as AS by renal tissue type IV collagen α3 and α5 chain immunofluorescence, 21 were diagnosed by EM, one was diagnosed by skin biopsy, and 12 were diagnosed by gene detection. Six novel mutations of COL4A5 gene were found. Forty-five cases were misdiagnosed before the diagnosis of AS. Forty-one of the 45 cases received steroids and/or immunosuppressant therapy.

CONCLUSIONSThe clinical manifestations and pathological changes are not specific in children with AS, resulting in a higher rate of misdiagnosis. Typical lesions of GBM under EM are only observed in a part of patients. There is a high novel mutation rate of COL4A5 in the detected AS children.

Child ; Child, Preschool ; Collagen Type IV ; genetics ; Diagnostic Errors ; Female ; Glomerular Basement Membrane ; pathology ; Humans ; Male ; Nephritis, Hereditary ; diagnosis ; genetics ; pathology ; Retrospective Studies

OBJECTIVETo analyze the clinical and genetic features of X-linked Alport syndrome (XLAS) in men positive for the collagen α5(Ⅳ) chain in epidermal basement membrane.

METHODThis was a retrospective study. Totally 725 families were diagnosed as Alport syndrome in Department of Pediatrics of Peking University First Hospital during January 1998 to December 2014, among them 450 patients were males with XLAS. Patients who met both of the following two criteria were included in this study. (1)Patients underwent α5(Ⅳ) chain staining in the epidermal basement membrane. (2)Mutations in COL4A5 gene were detected.Mann-Whitney test and χ(2) test were used.

RESULTTotally 140 males with XLAS were included in this study, 18 cases were α5 (Ⅳ)-positive and 122 cases were α5 (Ⅳ)-negative. The two groups of patients were compared, the median age at analysis was 11.0 vs. 7.2 years (Z = -1.839, P = 0.066), the 24-hour urine protein was 1.50 vs. 0.57 g/d (Z = -1.212, P = 0.226), the rate of hearing loss was 28% vs. 53% (χ(2) = 3.619, P = 0.067), the number of patients progressed to end stage renal disease (ESRD) was 4 vs. 12 (χ(2) =2.377, P = 0.128), the median age of ESRD was 31.0 vs. 16.6 years (Z = -2.554, P = 0.011), the rate of missense mutations in COL4A5 gene was 67% vs. 52% (χ(2) = 1.424, P = 0.313).

CONCLUSIONCompared the two groups of patients with positive and negative staining for the collagen Ⅳ α5 chain in epidermal basement membrane, there was no significant difference in the proteinuria level, the rate of hearing loss and genotype of COL4A5 gene. But the patients with positive staining progressed to ESRD significantly later than the patients with negative staining.

Basement Membrane ; pathology ; Child ; Collagen Type IV ; genetics ; DNA Mutational Analysis ; Deafness ; Humans ; Kidney Failure, Chronic ; Male ; Mutation, Missense ; Nephritis, Hereditary ; genetics ; pathology ; Proteinuria ; Retrospective Studies

OBJECTIVETo analyze the clinical and pathological features of children with Alport syndrome (AS).

METHODSA series of 47 patients with AS from unrelated families hospitalized from Jan. 1990 to Jan. 2007 were involved in this study. The clinical and histopathological data were collected and analyzed.

RESULTSOf the 47 cases, 32 were male and 15 female, M/F: 2.1:1. The patient's age ranged from 15 months to 13 years, mean 9 years. Thirty-nine of the 47 cases had positive family history, X-linked dominant inheritance AS was diagnosed in 37 cases, autosomal recessive inheritance AS in 2 cases. Gross hematuria or microscopic hematuria were found in 59.3% of the cases as the first manifestations, while 29.8% showed edema or proteinuria. The major clinical manifestations were isolated hematuria (23.4%), hematuria and proteinuria (36.2%), nephrotic syndrome (29.8%), and renal failure (10.6%). Hematuria and proteinuria existed in all the cases, while only 7 to 13 years children had nephrotic syndrome and renal failure. Of the 47 patients, 33 (70.2%) showed mesangial proliferative glomerulonephritis (MsPGN) under the light microscope, 13 (27.6%) focal segmental glomerulosclerosis (FSGS), 1 (2.1%) membrane proliferative glomerulonephritis (MPGN). For immunofluorescence, there was IgM (40.4%) as the dominant deposition in 19 patients, IgA in 9 (19.1%), IgG in 9 (19.1%), and 10 (21.4%) were negative. Thirty-nine cases showed typical glomerular basement membrane (GBM) pathological changes under electron microscope, while thin basement membrane in 8 cases; 46 showed abnormal skin and/or renal alpha-chain distribution.

CONCLUSIONFor Alport syndrome, number of male patients was higher than that of female patients. There was a significant difference among different age groups. Hematuria might be present throughout the course, while urine protein increases gradually. MsPGN was the dominant pathological change. The GBM pathological changes in younger children is not typical, so the immunofluorescence test of alpha-chain in collagen IV should be used as an important diagnostic method.

Adolescent ; Child ; Child, Preschool ; Collagen Type IV ; metabolism ; Female ; Humans ; Infant ; Kidney ; pathology ; Male ; Nephritis, Hereditary ; diagnosis ; genetics ; pathology ; Pedigree ; Retrospective Studies