1
|
Segura-Guerrero M, Saus C, Gozalbo-Rovira R, Cabello-Pelegrín S, Vargas ML, Martínez-Pomar N, Rodríguez-Díaz J, Saus J, Julià MR. Denovo glomerulonephritis associated with IgA anti-GBM alloantibodies after kidney transplantation in Alport syndrome: A case report with diagnostic implications. Clin Immunol 2024; 268:110354. [PMID: 39237079 DOI: 10.1016/j.clim.2024.110354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 07/03/2024] [Accepted: 08/28/2024] [Indexed: 09/07/2024]
Abstract
Alport syndrome (AS) is a hereditary disorder caused by pathogenic variants in COL4A3, COL4A4, or COL4A5 genes expressing α3, α4, and α5 chains of basement membrane type IV collagen (COL4). The triple-helical α3α4α5(IV) protomer is a major component of the mature glomerular basement membrane (GBM) whose defective formation in AS leads to structural GBM disruption and kidney dysfunction, often resulting in kidney replacement therapy. A genetically intact renal graft exposes the immune system to a non-tolerized α3α4α5(IV) component and an alloimmune response eventually ensues. So far, only IgG alloantibodies reacting against COL4 have been reported in AS alloimmune responses. Here, we report alloimmune glomerulonephritis mediated by IgA antibodies against the non-collagenous C-terminal domain 1 of the α5(IV) chain in a patient with autosomal recessive AS following a second kidney transplantation. The patient presented a not previously described biallelic variant in the COL4A4 gene. Immunological, diagnostic, and clinical implications are discussed.
Collapse
Affiliation(s)
- Marina Segura-Guerrero
- Immunology Department, Son Espases University Hospital, Balearic Islands Health Research Institute (IdISBa), Palma de Mallorca, Spain.
| | - Carlos Saus
- Pathology Department, Son Espases University Hospital, Balearic Islands Health Research Institute (IdISBa), Palma de Mallorca, Spain.
| | - Roberto Gozalbo-Rovira
- Microbiology Department, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain.
| | - Sheila Cabello-Pelegrín
- Nephrology Department, Son Espases University Hospital, Balearic Islands Health Research Institute (IdISBa), Palma de Mallorca, Spain.
| | | | - Natalia Martínez-Pomar
- Immunology Department, Son Espases University Hospital, Balearic Islands Health Research Institute (IdISBa), Palma de Mallorca, Spain.
| | - Jesús Rodríguez-Díaz
- Microbiology Department, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain.
| | - Juan Saus
- Biochemistry and Molecular Biology Department, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain.
| | - Maria Rosa Julià
- Immunology Department, Son Espases University Hospital, Balearic Islands Health Research Institute (IdISBa), Palma de Mallorca, Spain.
| |
Collapse
|
2
|
Zeni L, Mescia F, Toso D, Dordoni C, Mazza C, Savoldi G, Econimo L, Cortinovis R, Fisogni S, Alberici F, Scolari F, Izzi C. Clinical Significance of the Cystic Phenotype in Alport Syndrome. Am J Kidney Dis 2024; 84:320-328.e1. [PMID: 38514012 DOI: 10.1053/j.ajkd.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/16/2024] [Accepted: 02/02/2024] [Indexed: 03/23/2024]
Abstract
RATIONALE & OBJECTIVE Alport syndrome (AS) is the most common genetic glomerular disease caused by mutations that affect type IV collagen. However, the clinical characteristics and significance of AS with kidney cysts are not well defined. This study investigated the prevalence and clinical significance of cystic kidney phenotype in AS. STUDY DESIGN Retrospective cohort study. SETTING & PARTICIPANTS One hundred-eight patients with AS and a comparison cohort of 79 patients with IgA nephropathy (IgAN). Clinical, genetic, and imaging data were collected from medical records. EXPOSURE Cystic kidney phenotype evaluated by ultrasonography and defined as the presence of≥3 cysts in each kidney; demographic characteristics and estimated glomerular filtration rate (eGFR) at disease onset. OUTCOME Cystic kidney phenotype in the AS and IgAN cohorts; time to chronic kidney disease (CKD) stage 3b and longitudinal changes in eGFR in the AS cohort. ANALYTICAL APPROACH Logistic regression analysis to test independent strengths of associations of clinical/demographic features with the binary outcome of cystic phenotype. Survival analysis for the outcome of reaching CKD stage 3b and linear mixed models for changes in eGFR over time in the AS cohort. RESULTS We studied 108 patients with AS; 76 (70%) had a genetic diagnosis. Autosomal dominant AS was prevalent, accounting for 68% of patients with a genetic diagnosis. Cystic kidney phenotype was observed in 38% of patients with AS and was associated with normal-sized kidneys in all but 3 patients, who showed increased total kidney volume, mimicking autosomal dominant polycystic kidney disease. The prevalence of cystic kidney phenotype was significantly higher in patients with AS when compared with the group of patients with IgAN (42% vs 19%; P=0.002). Patients with the cystic kidney phenotype were older and had more marked reduction in eGFR than patients without cystic changes. Among patients with AS, the cystic phenotype was associated with older age and a faster decline eGFR. LIMITATIONS Retrospective, single-center study. CONCLUSIONS Cystic kidney phenotype is a common finding in AS. The cystic kidney phenotype is a common finding in AS, suggesting a possible role in cystogenesis for the genetic variants that cause this disease. PLAIN-LANGUAGE SUMMARY Hematuria is the classic renal presentation of Alport syndrome (AS), a hereditary glomerulopathy caused by pathogenic variants of the COL4A3-5 genes. An atypical kidney cystic phenotype has been rarely reported in individuals with these variants. To determine the prevalence of kidney cysts, we performed abdominal ultrasonography in a large group of patients with AS and a comparison group of patients with another glomerular kidney disease, IgA nephropathy (IgAN). Multiple kidney cysts, usually with normal kidney volume, were found in 38% of patients with AS. A few patients' kidney volumes were large enough to mimic a different hereditary cystic kidney disease, autosomal dominant polycystic kidney disease. The overall prevalence of kidney cysts in AS was more than double that observed in the well-matched comparison group with IgAN. These findings emphasize the high prevalence of cystic kidney phenotype in AS, suggesting a likely association between the genetic variants that cause this disease and the development of kidney cysts.
Collapse
Affiliation(s)
- Letizia Zeni
- Division of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili
| | - Federica Mescia
- Division of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili; Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Diego Toso
- Division of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili; Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Chiara Dordoni
- Clinical Genetics Unit, Department of Obstetrics and Gynaecology, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili
| | - Cinzia Mazza
- Medical Genetics Laboratory, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili
| | - Gianfranco Savoldi
- Medical Genetics Laboratory, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili
| | - Laura Econimo
- Division of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili
| | - Roberta Cortinovis
- Division of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili
| | - Simona Fisogni
- Section of Pathology, Department of Molecular and Translational Medicine, ASST-Spedali Civili, University of Brescia, Brescia, Italy
| | - Federico Alberici
- Division of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili; Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Francesco Scolari
- Division of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili; Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Claudia Izzi
- Clinical Genetics Unit, Department of Obstetrics and Gynaecology, Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili; Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
| |
Collapse
|
3
|
Vivante A. Genetics of Chronic Kidney Disease. N Engl J Med 2024; 391:627-639. [PMID: 39141855 DOI: 10.1056/nejmra2308577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Affiliation(s)
- Asaf Vivante
- From the Department of Pediatrics and the Pediatric Nephrology Unit, Edmond and Lily Safra Children's Hospital, and the Nephro-Genetics Clinic and Genetic Kidney Disease Research Laboratory, Sheba Medical Center, Tel Hashomer, and the Faculty of Medicine, Tel Aviv University, Tel Aviv - all in Israel
| |
Collapse
|
4
|
Younsi ME, Achour A, Kraoua L, Nesrine M, Sayari T, Abderrahim E, Laabidi J, Zouaghi MK, Kharrat M, Gargah T, Trabelsi M, M'rad R. Genetic study of Alport syndrome in Tunisia. Pediatr Nephrol 2024:10.1007/s00467-024-06474-7. [PMID: 39138691 DOI: 10.1007/s00467-024-06474-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 06/13/2024] [Accepted: 07/11/2024] [Indexed: 08/15/2024]
Abstract
BACKGROUND Alport syndrome is a genetic disorder affecting the kidneys, ears, and eyes, causing chronic kidney disease, sensorineural hearing loss, and ocular abnormalities. It results from pathogenic variants in the COL4A3, COL4A4, or COL4A5 genes, with different inheritance patterns: X-linked from COL4A5 variants, autosomal recessive from homozygous variants in COL4A3 or COL4A4, digenic from variants in both COL4A3 and COL4A4, and autosomal dominant from heterozygous variants in COL4A3 or COL4A4. METHODS We analyzed 45 patients with Alport syndrome from 11 Tunisian families to determine their clinical and genetic characteristics. Clinical data were collected retrospectively, and whole-exome sequencing was conducted on one patient from each family. Sanger sequencing validated pathogenic variants, and cascade screening extended the analysis to 53 individuals. RESULTS We identified nine likely pathogenic variants among 11 index cases: six novel and three known variations. Of these, five were in COL4A3, and four were in COL4A5, with variants including frameshift, nonsense, missense, and alternative splicing. Most variations affected the Gly-XY codon. Among the 45 clinically identified siblings, 30 tested positive for Alport syndrome. The cascade screening identified 3 additional affected individuals, 10 unaffected siblings, and 10 unaffected parents. The mode of inheritance was autosomal recessive in six families and X-linked in four families. CONCLUSIONS This study is the first to screen the mutational spectrum of Alport syndrome in Tunisia. It reveals novel pathogenic variants and suggests that autosomal recessive inheritance may be more common in the Tunisian population than X-linked inheritance, contrary to existing literature.
Collapse
Affiliation(s)
- Mariem El Younsi
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
| | - Ahlem Achour
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Lilia Kraoua
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Mezzi Nesrine
- Laboratory of Biomedical Genomics and Oncogenetics, Pasteur Institute of Tunis, 1002, Tunis, Tunisia
| | - Taha Sayari
- Service de Néphrologie Pédiatrique, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Ezzeddine Abderrahim
- Service de Médecine Interne Et de Néphrologie Adulte, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Janet Laabidi
- Service Néphrologie, L'Hôpital Militaire Principal d'Instruction de Tunis, MontFleury, 1008, Tunis, Tunisia
| | - Mohamed Karim Zouaghi
- Service de Néphrologie, Dialyse Et Transplantation Rénale, Hôpital La Rabta 1007, Tunis, Tunisia
| | - Maher Kharrat
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
| | - Tahar Gargah
- Service de Néphrologie Pédiatrique, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Mediha Trabelsi
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Ridha M'rad
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia.
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia.
| |
Collapse
|
5
|
Mitrotti A, Giliberti M, Di Leo V, di Bari I, Pontrelli P, Gesualdo L. Hidden genetics behind glomerular scars: an opportunity to understand the heterogeneity of focal segmental glomerulosclerosis? Pediatr Nephrol 2024; 39:1685-1707. [PMID: 37728640 PMCID: PMC11026212 DOI: 10.1007/s00467-023-06046-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 05/02/2023] [Accepted: 05/30/2023] [Indexed: 09/21/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a complex disease which describes different kinds of kidney defects, not exclusively linked with podocyte defects. Since nephrin mutation was first described in association with early-onset nephrotic syndrome (NS), many advancements have been made in understanding genetic patterns associated with FSGS. New genetic causes of FSGS have been discovered, displaying unexpected genotypes, and recognizing possible site of damage. Many recent large-scale sequencing analyses on patients affected by idiopathic chronic kidney disease (CKD), kidney failure (KF) of unknown origin, or classified as FSGS, have revealed collagen alpha IV genes, as one of the most frequent sites of pathogenic mutations. Also, recent interest in complex and systemic lysosomal storage diseases, such as Fabry disease, has highlighted GLA mutations as possible causes of FSGS. Tubulointerstitial disease, recently classified by KDIGO based on genetic subtypes, when associated with UMOD variants, may phenotypically gain FSGS features, as well as ciliopathy genes or others, otherwise leading to completely different phenotypes, but found carrying pathogenic variants with associated FSGS phenotype. Thus, glomerulosclerosis may conceal different heterogeneous conditions. When a kidney biopsy is performed, the principal objective is to provide an accurate diagnosis. The broad spectrum of phenotypic expression and genetic complexity is demonstrating that a combined path of management needs to be applied. Genetic investigation should not be reserved only to selected cases, but rather part of medical management, integrating with clinical and renal pathology records. FSGS heterogeneity should be interpreted as an interesting opportunity to discover new pathways of CKD, requiring prompt genotype-phenotype correlation. In this review, we aim to highlight how FSGS represents a peculiar kidney condition, demanding multidisciplinary management, and in which genetic analysis may solve some otherwise unrevealed idiopathic cases. Unfortunately there is not a uniform correlation between specific mutations and FSGS morphological classes, as the same variants may be identified in familial cases or sporadic FSGS/NS or manifest a variable spectrum of the same disease. These non-specific features make diagnosis challenging. The complexity of FSGS genotypes requires new directions. Old morphological classification does not provide much information about the responsible cause of disease and misdiagnoses may expose patients to immunosuppressive therapy side effects, mistaken genetic counseling, and misguided kidney transplant programs.
Collapse
Affiliation(s)
- Adele Mitrotti
- Precision and Regenerative Medicine and Ionian Area, Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy.
| | - Marica Giliberti
- Precision and Regenerative Medicine and Ionian Area, Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Vincenzo Di Leo
- Precision and Regenerative Medicine and Ionian Area, Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Ighli di Bari
- Precision and Regenerative Medicine and Ionian Area, Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Paola Pontrelli
- Precision and Regenerative Medicine and Ionian Area, Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Loreto Gesualdo
- Precision and Regenerative Medicine and Ionian Area, Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| |
Collapse
|
6
|
Mabillard H, Ryan R, Tzoumas N, Gear S, Sayer JA. Explaining Alport syndrome-lessons from the adult nephrology clinic. JOURNAL OF RARE DISEASES (BERLIN, GERMANY) 2024; 3:14. [PMID: 38745975 PMCID: PMC11088994 DOI: 10.1007/s44162-024-00036-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 02/15/2024] [Indexed: 05/16/2024]
Abstract
Alport syndrome is a genetic kidney disease that causes worsening of kidney function over time, often progressing to kidney failure. Some types of Alport syndrome cause other symptoms and signs, including hearing loss and eye abnormalities. Research now indicates that Alport syndrome (autosomal dominant inheritance) is the most common form. Alport syndrome can have X-linked or a rare form of autosomal recessive inheritance. Traditionally, a kidney biopsy was used to diagnose Alport syndrome, but genetic testing provides a more precise and less invasive means of diagnosis and reveals the underlying pattern of inheritance. At present, there are no specific curative treatments for Alport syndrome however there is a strong international effort in pursuit of future therapies. Currently, angiotensin-converting enzyme inhibitors (ACEi), or an angiotensin receptor blocker (ARB) if a patient cannot tolerate an ACEi, slow down the progression of kidney disease and can delay the onset of kidney failure by years. There are other potential treatments in research that potentially can help delay the onset of kidney issues. Early treatment of patients and identification of their at-risk relatives is a priority. People living with Alport syndrome and their doctors now benefit from an active international research community working on translating further treatments into clinical practice and providing up-to-date clinical guidelines.
Collapse
Affiliation(s)
- Holly Mabillard
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle Upon Tyne, UK
| | - Rebecca Ryan
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
| | - Nik Tzoumas
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Central Parkway, Newcastle Upon Tyne, UK
- Sunderland Eye Infirmary, Sunderland, UK
| | - Susie Gear
- Alport UK, Cirencester, Gloucestershire, UK
| | - John A. Sayer
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle Upon Tyne, UK
| |
Collapse
|
7
|
Venda J, Henriques A, Leal R, Alves R. Coexisting presentation of two rare genetic variants of autosomal dominant polycystic kidney disease and Alport syndrome. BMJ Case Rep 2024; 17:e259500. [PMID: 38740443 DOI: 10.1136/bcr-2023-259500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024] Open
Abstract
Alport syndrome and autosomal dominant polycystic kidney disease are monogenic causes of chronic kidney disease and end-stage kidney failure. We present a case of a man in his 60s with progressive chronic kidney disease, bilateral sensorineural hearing loss and multiple renal cysts. Genetic analysis revealed a heterozygous variant in COL4A3 (linked to Alport syndrome) and in the GANAB gene (associated with a milder form of autosomal dominant polycystic kidney disease). Although each variant confers a mild risk of developing end-stage kidney disease, the patient presented a pronounced and accelerated progression of chronic kidney disease, which goes beyond what would be predicted by adding up their individual effects. This suggests a potential synergic effect of both variants, which warrants further investigation.
Collapse
Affiliation(s)
- João Venda
- Department of Nephrology, Coimbra Hospital and University Centre, Coimbra, Portugal
| | - Andreia Henriques
- Department of Nephrology, Coimbra Hospital and University Centre, Coimbra, Portugal
| | - Rita Leal
- Department of Nephrology, Coimbra Hospital and University Centre, Coimbra, Portugal
- University of Coimbra, Coimbra, Portugal
| | - Rui Alves
- Department of Nephrology, Coimbra Hospital and University Centre, Coimbra, Portugal
- University of Coimbra, Coimbra, Portugal
| |
Collapse
|
8
|
Graziani L, Minotti C, Carriero ML, Bengala M, Lai S, Terracciano A, Novelli A, Novelli G. A Novel COL4A5 Pathogenic Variant Joins the Dots in a Family with a Synchronous Diagnosis of Alport Syndrome and Polycystic Kidney Disease. Genes (Basel) 2024; 15:597. [PMID: 38790225 PMCID: PMC11121527 DOI: 10.3390/genes15050597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/30/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Alport Syndrome (AS) is the most common genetic glomerular disease, and it is caused by COL4A3, COL4A4, and COL4A5 pathogenic variants. The classic phenotypic spectrum associated with AS ranges from isolated hematuria to chronic kidney disease (CKD) with extrarenal abnormalities. Atypical presentation of the disorder is possible, and it can mislead the diagnosis. Polycystic kidney disease (PKD), which is most frequently associated with Autosomal Dominant PKD (ADPKD) due to PKD1 and PKD2 heterozygous variants, is emerging as a possible clinical manifestation in COL4A3-A5 patients. We describe a COL4A5 novel familial frameshift variant (NM_000495.5: c.1095dup p.(Leu366ValfsTer45)), which was associated with AS and PKD in the hemizygous proband, as well as with PKD, IgA glomerulonephritis and focal segmental glomerulosclerosis (FSGS) in the heterozygous mother. Establishing the diagnosis of AS can sometimes be difficult, especially in the context of misleading family history and atypical phenotypic features. This case study supports the emerging genotypic and phenotypic heterogeneity in COL4A3-A5-associated disorders, as well as the recently described association between PKD and collagen type IV (Col4) defects. We highlight the importance of the accurate phenotyping of all family members and the relevance of next-generation sequencing in the differential diagnosis of hereditary kidney disease.
Collapse
Affiliation(s)
- Ludovico Graziani
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.M.); (M.L.C.); (G.N.)
| | - Chiara Minotti
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.M.); (M.L.C.); (G.N.)
| | - Miriam Lucia Carriero
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.M.); (M.L.C.); (G.N.)
| | - Mario Bengala
- Medical Genetics Unit, Tor Vergata University Hospital, 00133 Rome, Italy;
| | - Silvia Lai
- Division of Nephrology, Department of Translational and Precision Medicine, “Sapienza” University, 00133 Rome, Italy;
| | - Alessandra Terracciano
- Translational Cytogenomics Research Unit, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy; (A.T.); (A.N.)
| | - Antonio Novelli
- Translational Cytogenomics Research Unit, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy; (A.T.); (A.N.)
| | - Giuseppe Novelli
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.M.); (M.L.C.); (G.N.)
- Medical Genetics Unit, Tor Vergata University Hospital, 00133 Rome, Italy;
| |
Collapse
|
9
|
Chavez E, Goncalves S, Rheault MN, Fornoni A. Alport Syndrome. ADVANCES IN KIDNEY DISEASE AND HEALTH 2024; 31:170-179. [PMID: 39004457 DOI: 10.1053/j.akdh.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 02/10/2024] [Accepted: 02/28/2024] [Indexed: 07/16/2024]
Abstract
Alport syndrome (AS) is characterized by progressive kidney failure, hematuria, sensorineural hearing loss, and ocular abnormalities. Pathogenic variants in the COL4A3-5 genes result in a defective deposition of the collagen IV α3α4α5 protomers in the basement membranes of the glomerulus in the kidney, the cochlea in the ear and the cornea, lens capsule and retina in the eye. The presence of a large variety of COL4A3-5 gene(s) pathogenetic variants irrespective of the mode of inheritance (X-linked, autosomal recessive, autosomal dominant, or digenic) with and without syndromic features is better defined as the "Alport spectrum disorder", and represents the most common cause of genetic kidney disease and the second most common cause of genetic kidney failure. The clinical course and prognosis of individuals with AS is highly variable. It is influenced by gender, mode of inheritance, affected gene(s), type of genetic mutation, and genetic modifiers. This review article will discuss the epidemiology, classification, pathogenesis, diagnosis, clinical course with genotype-phenotype correlations, and current and upcoming treatment of patients with AS. It will also review current recommendations with respect to when to evaluate for hearing loss or ophthalmologic abnormalities.
Collapse
Affiliation(s)
- Efren Chavez
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL.
| | - Stefania Goncalves
- Department of Otolaryngology-Head and Neck Surgery, University of Miami Miller School of Medicine, University of Miami Ear Institute, Miami, FL
| | - Michelle N Rheault
- Department of Pediatrics, University of Minnesota Masonic Children's Hospital, Minneapolis, MN
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL; Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL.
| |
Collapse
|
10
|
Puapatanakul P, Miner JH. Alport syndrome and Alport kidney diseases - elucidating the disease spectrum. Curr Opin Nephrol Hypertens 2024; 33:283-290. [PMID: 38477333 PMCID: PMC10990029 DOI: 10.1097/mnh.0000000000000983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
PURPOSE OF REVIEW With the latest classification, variants in three collagen IV genes, COL4A3 , COL4A4 , and COL4A5 , represent the most prevalent genetic kidney disease in humans, exhibiting diverse, complex, and inconsistent clinical manifestations. This review breaks down the disease spectrum and genotype-phenotype correlations of kidney diseases linked to genetic variants in these genes and distinguishes "classic" Alport syndrome (AS) from the less severe nonsyndromic genetically related nephropathies that we suggest be called "Alport kidney diseases". RECENT FINDINGS Several research studies have focused on the genotype-phenotype correlation under the latest classification scheme of AS. The historic diagnoses of "benign familial hematuria" and "thin basement membrane nephropathy" linked to heterozygous variants in COL4A3 or COL4A4 are suggested to be obsolete, but instead classified as autosomal AS by recent expert consensus due to a significant risk of disease progression. SUMMARY The concept of Alport kidney disease extends beyond classic AS. Patients carrying pathogenic variants in any one of the COL4A3/A4/A5 genes can have variable phenotypes ranging from completely normal/clinically unrecognizable, hematuria without or with proteinuria, or progression to chronic kidney disease and kidney failure, depending on sex, genotype, and interplays of other genetic as well as environmental factors.
Collapse
Affiliation(s)
- Pongpratch Puapatanakul
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Jeffrey H. Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
11
|
Duan Y, Cai B, Guo J, Wang C, Mai Q, Xu Y, Zeng Y, Shi Y, Wang B, Ding C, Chen M, Zhou C, Xu Y. GDF9 His209GlnfsTer6/S428T and GDF9 Q321X/S428T bi-allelic variants caused female subfertility with defective follicle enlargement. Cell Commun Signal 2024; 22:235. [PMID: 38643161 PMCID: PMC11031944 DOI: 10.1186/s12964-024-01616-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/12/2024] [Indexed: 04/22/2024] Open
Abstract
BACKGROUND Antral follicles consist of an oocyte cumulus complex surrounding by somatic cells, including mural granulosa cells as the inner layer and theca cells as the outsider layer. The communications between oocytes and granulosa cells have been extensively explored in in vitro studies, however, the role of oocyte-derived factor GDF9 on in vivo antral follicle development remains elusive due to lack of an appropriate animal model. Clinically, the phenotype of GDF9 variants needs to be determined. METHODS Whole-exome sequencing (WES) was performed on two unrelated infertile women characterized by an early rise of estradiol level and defect in follicle enlargement. Besides, WES data on 1,039 women undergoing ART treatment were collected. A Gdf9Q308X/S415T mouse model was generated based on the variant found in one of the patients. RESULTS Two probands with bi-allelic GDF9 variants (GDF9His209GlnfsTer6/S428T, GDF9Q321X/S428T) and eight GDF9S428T heterozygotes with normal ovarian response were identified. In vitro experiments confirmed that these variants caused reduction of GDF9 secretion, and/or alleviation in BMP15 binding. Gdf9Q308X/S415T mouse model was constructed, which recapitulated the phenotypes in probands with abnormal estrogen secretion and defected follicle enlargement. Further experiments in mouse model showed an earlier expression of STAR in small antral follicles and decreased proliferative capacity in large antral follicles. In addition, RNA sequencing of granulosa cells revealed the transcriptomic profiles related to defective follicle enlargement in the Gdf9Q308X/S415T group. One of the downregulated genes, P4HA2 (a collagen related gene), was found to be stimulated by GDF9 protein, which partly explained the phenotype of defective follicle enlargement. CONCLUSIONS GDF9 bi-allelic variants contributed to the defect in antral follicle development. Oocyte itself participated in the regulation of follicle development through GDF9 paracrine effect, highlighting the essential role of oocyte-derived factors on ovarian response.
Collapse
Affiliation(s)
- Yuwei Duan
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Bing Cai
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Jing Guo
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Chen Wang
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Qingyun Mai
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Yan Xu
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Yang Zeng
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Yue Shi
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Boyan Wang
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Chenhui Ding
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Minghui Chen
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Canquan Zhou
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China
| | - Yanwen Xu
- Department of Gynecology & Obstetrics, Center for Reproductive Medicine, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, 510080, China.
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, Guangdong, 510080, China.
- Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Guangzhou, Guangdong, 510080, China.
| |
Collapse
|
12
|
Schott C, Colaiacovo S, Baker C, Weir MA, Connaughton DM. Reclassification of Genetic Testing Results: A Case Report Demonstrating the Need for Structured Re-Evaluation of Genetic Findings. Can J Kidney Health Dis 2024; 11:20543581241242562. [PMID: 38623282 PMCID: PMC11017705 DOI: 10.1177/20543581241242562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 03/01/2024] [Indexed: 04/17/2024] Open
Abstract
Rationale Alport Syndrome (AS) is a progressive genetic condition characterized by chronic kidney disease (CKD), hearing loss, and eye abnormalities. It is caused by mutations in the genes COL4A3, COL4A4, and COL4A5. Heterozygous mutations in COL4A4 and COL4A3 cause autosomal dominant Alport Syndrome (ADAS), and a spectrum of phenotypes ranging from asymptomatic hematuria to CKD, with variable extra-renal features. In the past, heterozygous mutations in these genes were thought to be benign, however recent studies show that about 30% of patients can progress to CKD, and 15% can progress to end stage kidney disease (ESKD). Presenting Concerns We present a case of a woman who was noted to have microscopic hematuria pre-living kidney donation. Genetic testing revealed a heterozygous variant of uncertain significance (VUS) in the COL4A4 gene. VUSs are medically nonactionable findings and data show that VUSs can be detected in 41% of all patients who undergo clinical genetic testing. VUSs frustrate clinicians and patients alike. Although they cannot be used in medical decision-making, data suggest that reanalysis can result in the reclassification of a VUS over time. Diagnosis Post-donation, the index patient had a higher than anticipated rise in serum creatinine, raising a concern for possible intrinsic kidney disease. Kidney biopsy was deemed high risk in the setting of a unilateral kidney thereby limiting possible diagnostic intervention to determine the cause of disease. Intervention Re-evaluation of prior genetic testing results and reassessment of the previously identified VUS in COL4A4 was performed 5-years post-donation. These analyses, along with the addition of new phenotypic data and extended pedigree data, resulted in the reclassification of the previously identified VUS to a likely pathogenic variant. Outcomes This case demonstrates the importance of structured, periodic re-evaluation of genetic testing results. With the ever-changing landscape of genetics in medicine, the interpretation of a VUS can be dynamic and therefore warrant caution in living kidney donor evaluations. Studies have shown that about 10% of VUSs can be upgraded to a pathogenic classification after an 18- to 36-month interval. Structured re-evaluation of genomic testing results has not yet been integrated into clinical practice and poses a unique challenge in living kidney donation. Novel findings This case report highlights the variability of the ADAS phenotype caused by pathogenic heterozygous variants in the type 4 collagen genes. It supports the nomenclature change from a benign hematuria phenotype to ADAS, particularly when additional risk factors such as proteinuria, focal segmental glomerulosclerosis or glomerular basement membrane changes on kidney biopsy are present, or as in this case, evidence of disease in other family members.
Collapse
Affiliation(s)
- Clara Schott
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western, London, ON, Canada
| | - Samantha Colaiacovo
- Division of Medical Genetics, Department of Pediatrics, Victoria Hospital, London Health Science Center, ON, Canada
| | - Cadence Baker
- Division of Nephrology, Department of Medicine, University Hospital, London Health Sciences Centre, ON, Canada
| | - Matthew A. Weir
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western, London, ON, Canada
- Department of Epidemiology and Biostatistics, Schulich School of Medicine & Dentistry, University of Western, London, ON, Canada
| | - Dervla M. Connaughton
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western, London, ON, Canada
- Division of Nephrology, Department of Medicine, University Hospital, London Health Sciences Centre, ON, Canada
| |
Collapse
|
13
|
Yavas C, Ozgenturk NO, Dogan M, Gezdirici A, Keskin E, İli EG, Dogan T, Celebi E, Bender O, Un C. A Deeper Insight into COL4A3, COL4A4, and COL4A5 Variants and Genotype-Phenotype Correlation of a Turkish Cohort with Alport Syndrome. Mol Syndromol 2024; 15:1-13. [PMID: 38357258 PMCID: PMC10862325 DOI: 10.1159/000533915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/26/2023] [Indexed: 02/16/2024] Open
Abstract
Introduction Alport syndrome (AS) is an inherited, rare, progressive kidney disease that affects the eye and ear physiology. Pathogenic variants of COL4A5 account for 85% of all cases, while COL4A3 and COL4A4 account for the remaining 15%. Methods Targeted next-generation sequencing of the COL4A3, COL4A4, and COL4A5 genes was performed in 125 Turkish patients with AS. The patients were compared to 45 controls and open-access population data. Results The incidence of AS variants in patients was found as 21.6%. 27 variants were identified as pathogenic/likely pathogenic, 28 as variant of uncertain significance, and 52 as benign/likely benign. We also found 31 novel variants (14 in COL4A3, 6 in COL4A4, and 11 in COL4A5) of which 27 were classified as pathogenic/likely pathogenic. Pathogenic/likely Pathogenic variants were most commonly found in the COL4A5 gene, consistent with the literature. This study contributed novel variants associated with AS to the literature. Conclusion Genetic testing is a crucial part for the diagnosis and management of AS. Studies on the genetic etiology of AS are limited for the Turkish population. We believe that this study will contribute to the literature and the clinical decision-making process of patients with AS and emphasize the importance of genetic counseling.
Collapse
Affiliation(s)
- Cuneyd Yavas
- Department of Medical Genetics, Başaksehir Çam and Sakura City Hospital, Istanbul, Turkey
| | - Nehir Ozdemir Ozgenturk
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Yildiz Technical University, Istanbul, Turkey
| | - Mustafa Dogan
- Department of Medical Genetics, Başaksehir Çam and Sakura City Hospital, Istanbul, Turkey
| | - Alper Gezdirici
- Department of Medical Genetics, Başaksehir Çam and Sakura City Hospital, Istanbul, Turkey
| | - Ece Keskin
- Haseki Training and Research Hospital, Clinic of Medical Genetic, Istanbul, Turkey
| | - Ezgi Gokpınar İli
- Department of Medical Genetics, Başaksehir Çam and Sakura City Hospital, Istanbul, Turkey
| | - Tunay Dogan
- Department of Pathology, Faculty of Medicine, Istinye University, Istanbul, Turkey
| | - Evrim Celebi
- Department of Medical Genetics, Başaksehir Çam and Sakura City Hospital, Istanbul, Turkey
| | - Onur Bender
- Biotechnology Institute, Ankara University, Ankara, Turkey
| | - Cemal Un
- Department of Biology Molecular Biology Section, Ege University Faculty of Science, İzmir, Turkey
| |
Collapse
|
14
|
Uedono H, Mori K, Nakatani S, Watanabe K, Nakaya R, Morioka F, Sone K, Ono C, Hotta J, Tsuda A, Morisada N, Seto T, Nozu K, Emoto M. Novel Digenic Variants in COL4A4 and COL4A5 Causing X-Linked Alport Syndrome: A Case Report. Case Rep Nephrol Dial 2024; 14:1-9. [PMID: 38179179 PMCID: PMC10764090 DOI: 10.1159/000535493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 11/18/2023] [Indexed: 01/06/2024] Open
Abstract
Introduction Alport syndrome (AS) is a hereditary, progressive kidney disease characterized by structural abnormalities and dysfunction of the glomerular basement membrane (GBM). AS is classified as X-linked, autosomal, and digenic. The number of cases of digenic AS has increased, but the genotype-phenotype correlation of patient with digenic AS is still unclear. Here, we present a case of digenic AS with novel digenic missense variants in COL4A4 (c.827G>C, p.Gly276Ala) and COL4A5 (c.4369G>C, p.Gly1457Arg). Case Presentation The patient was a 29-year-old Japanese man suffering from persistent microscopic hematuria and proteinuria without kidney function impairment. Kidney biopsy showed focal interstitial foam cell infiltration, global and segmental glomerulosclerosis. Immunofluorescence staining for collagen IV α5 was almost negative in the GBM and Bowman's capsule. Electron microscopy revealed irregular thickening with lamellation and segmental thinning of the GBM. Clinical and pathological findings were consistent with AS. Comprehensive next-generation sequencing revealed a heterozygous missense variant in COL4A4 (c.827G>C, p.Gly276Ala) in exon 1 and a hemizygous missense variant in COL4A5 (c.4369G>C, p.Gly1457Arg) in exon 49 on the patient's paternal and maternal alleles, respectively. The same digenic variants were detected in his sister, and she also showed a similar phenotype. After treatment with angiotensin-converting enzyme inhibitors, proteinuria decreased from 2.3 to 1.1 g/g creatinine, but occult blood persisted. During follow-up, kidney function has been preserved. Conclusion The novel genotype of our case provides more information on the genotype-phenotype correlation of digenic XLAS, although long-term follow-up is required. The findings in the present case also indicate the importance of genetic tests for family members of a patient diagnosed with digenic AS.
Collapse
Affiliation(s)
- Hideki Uedono
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Katsuhito Mori
- Department of Nephrology, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Shinya Nakatani
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Kohei Watanabe
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Rino Nakaya
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Fumiyuki Morioka
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Kazuma Sone
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Chie Ono
- Department of Medical Genetics, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Junko Hotta
- Department of Medical Genetics, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Akihiro Tsuda
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Naoya Morisada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Toshiyuki Seto
- Department of Medical Genetics, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masanori Emoto
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
- Department of Nephrology, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| |
Collapse
|
15
|
Cipriani V, Vestito L, Magavern EF, Jacobsen JO, Arno G, Behr ER, Benson KA, Bertoli M, Bockenhauer D, Bowl MR, Burley K, Chan LF, Chinnery P, Conlon P, Costa M, Davidson AE, Dawson SJ, Elhassan E, Flanagan SE, Futema M, Gale DP, García-Ruiz S, Corcia CG, Griffin HR, Hambleton S, Hicks AR, Houlden H, Houlston RS, Howles SA, Kleta R, Lekkerkerker I, Lin S, Liskova P, Mitchison H, Morsy H, Mumford AD, Newman WG, Neatu R, O'Toole EA, Ong AC, Pagnamenta AT, Rahman S, Rajan N, Robinson PN, Ryten M, Sadeghi-Alavijeh O, Sayer JA, Shovlin CL, Taylor JC, Teltsh O, Tomlinson I, Tucci A, Turnbull C, van Eerde AM, Ware JS, Watts LM, Webster AR, Westbury SK, Zheng SL, Caulfield M, Smedley D. Rare disease gene association discovery from burden analysis of the 100,000 Genomes Project data. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.20.23300294. [PMID: 38196618 PMCID: PMC10775325 DOI: 10.1101/2023.12.20.23300294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
To discover rare disease-gene associations, we developed a gene burden analytical framework and applied it to rare, protein-coding variants from whole genome sequencing of 35,008 cases with rare diseases and their family members recruited to the 100,000 Genomes Project (100KGP). Following in silico triaging of the results, 88 novel associations were identified including 38 with existing experimental evidence. We have published the confirmation of one of these associations, hereditary ataxia with UCHL1 , and independent confirmatory evidence has recently been published for four more. We highlight a further seven compelling associations: hypertrophic cardiomyopathy with DYSF and SLC4A3 where both genes show high/specific heart expression and existing associations to skeletal dystrophies or short QT syndrome respectively; monogenic diabetes with UNC13A with a known role in the regulation of β cells and a mouse model with impaired glucose tolerance; epilepsy with KCNQ1 where a mouse model shows seizures and the existing long QT syndrome association may be linked; early onset Parkinson's disease with RYR1 with existing links to tremor pathophysiology and a mouse model with neurological phenotypes; anterior segment ocular abnormalities associated with POMK showing expression in corneal cells and with a zebrafish model with developmental ocular abnormalities; and cystic kidney disease with COL4A3 showing high renal expression and prior evidence for a digenic or modifying role in renal disease. Confirmation of all 88 associations would lead to potential diagnoses in 456 molecularly undiagnosed cases within the 100KGP, as well as other rare disease patients worldwide, highlighting the clinical impact of a large-scale statistical approach to rare disease gene discovery.
Collapse
|
16
|
Tkemaladze T, Bregvadze K, Kvaratskhelia E, Abzianidze E, Davitaia T. A founder COL4A3 pathogenic variant resulting in Alport syndrome and thin basement membrane disease: a case report series. Front Med (Lausanne) 2023; 10:1281049. [PMID: 38188341 PMCID: PMC10768050 DOI: 10.3389/fmed.2023.1281049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/05/2023] [Indexed: 01/09/2024] Open
Abstract
Alport syndrome is a rare genetic condition characterized by kidney disease, hearing impairment, and ocular abnormalities. It exhibits various inheritance patterns involving pathogenic variants in COL4A3, COL4A4, and COL4A5 genes. The phenotypes can range from isolated hematuria with a non-progressive or very slowly progressive course to progressive kidney disease with extrarenal abnormalities. Timely diagnosis of Alport syndrome facilitates the early and effective implementation of treatment, as well as genetic counseling. Here, we report the COL4A3 c.765G > A, p.((=)) mutation in three ethnically Azerbaijani, apparently unrelated, consanguineous families from the village of Algeti in the Marneuli region of Georgia. We speculate that this variant could represent a founder mutation within this population and recommend offering genetic testing to Algeti village residents with persistent hematuria.
Collapse
Affiliation(s)
- Tinatin Tkemaladze
- Department of Molecular and Medical Genetics, Tbilisi State Medical University, Tbilisi, Georgia
- Department of Pediatrics, Givi Zhvania Pediatric Academic Clinic, Tbilisi State Medical University, Tbilisi, Georgia
| | - Kakha Bregvadze
- Department of Molecular and Medical Genetics, Tbilisi State Medical University, Tbilisi, Georgia
| | - Eka Kvaratskhelia
- Department of Molecular and Medical Genetics, Tbilisi State Medical University, Tbilisi, Georgia
| | - Elene Abzianidze
- Department of Molecular and Medical Genetics, Tbilisi State Medical University, Tbilisi, Georgia
| | - Tinatin Davitaia
- Department of Pediatrics, Givi Zhvania Pediatric Academic Clinic, Tbilisi State Medical University, Tbilisi, Georgia
| |
Collapse
|
17
|
Mahrous NN, Jamous YF, Almatrafi AM, Fallatah DI, Theyab A, Alanati BH, Alsagaby SA, Alenazi MK, Khan MI, Hawsawi YM. A Current Landscape on Alport Syndrome Cases: Characterization, Therapy and Management Perspectives. Biomedicines 2023; 11:2762. [PMID: 37893135 PMCID: PMC10604007 DOI: 10.3390/biomedicines11102762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 09/30/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
Alport syndrome (AS) is a rare genetic disorder categorized by the progressive loss of kidney function, sensorineural hearing loss and eye abnormalities. It occurs due to mutations in three genes that encode for the alpha chains of type IV collagen. Globally, the disease is classified based on the pattern of inheritance into X-linked AS (XLAS), which is caused by pathogenic variants in COL4A5, representing 80% of AS. Autosomal recessive AS (ARAS), caused by mutations in either COL4A3 or COL4A4, represents 15% of AS. Autosomal dominant AS (ADAS) is rare and has been recorded in 5% of all cases due to mutations in COL4A3 or COL4A4. This review provides updated knowledge about AS including its clinical and genetic characteristics in addition to available therapies that only slow the progression of the disease. It also focuses on reported cases in Saudi Arabia and their prevalence. Moreover, we shed light on advances in genetic technologies like gene editing using CRISPR/Cas9 technology, the need for an early diagnosis of AS and managing the progression of the disease. Eventually, we provide a few recommendations for disease management, particularly in regions like Saudi Arabia where consanguineous marriages increase the risk.
Collapse
Affiliation(s)
- Nahed N. Mahrous
- Department of Biological Sciences, College of Science, University of Hafr Al-Batin, Hafr Al-Batin 39524, Saudi Arabia;
| | - Yahya F. Jamous
- The National Center of Vaccines and Bioprocessing, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia;
| | - Ahmad M. Almatrafi
- Department of Biological Sciences, College of Science, Taibah University, Madinah 42353, Saudi Arabia;
| | - Deema I. Fallatah
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia;
| | - Abdulrahman Theyab
- Department of Laboratory and Blood Bank, Security Forces Hospital, Makkah 11481, Saudi Arabia;
- Department of Biochemistry & Molecular Medicine, College of Medicine, Al-Faisal University, P.O. Box 50927, Riyadh 11533, Saudi Arabia
| | - Bayan H. Alanati
- Center for Synthetic Microbiology, Bioinformatics Core Facility, University of Marburg, 35032 Marburg, Germany;
| | - Suliman A. Alsagaby
- Department of Medicinal Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al-Majmaah 11952, Saudi Arabia;
| | - Munifa K. Alenazi
- Research Center, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah 21499, Saudi Arabia; (M.K.A.); (M.I.K.)
| | - Mohammed I. Khan
- Research Center, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah 21499, Saudi Arabia; (M.K.A.); (M.I.K.)
| | - Yousef M. Hawsawi
- Department of Biochemistry & Molecular Medicine, College of Medicine, Al-Faisal University, P.O. Box 50927, Riyadh 11533, Saudi Arabia
- Research Center, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah 21499, Saudi Arabia; (M.K.A.); (M.I.K.)
| |
Collapse
|
18
|
Adone A, Anjankar A. Alport Syndrome: A Comprehensive Review. Cureus 2023; 15:e47129. [PMID: 38021591 PMCID: PMC10649250 DOI: 10.7759/cureus.47129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Alport syndrome is an genetic disorder that distresses the basement membrane of the kidneys and can also impact other organs, such as the cochlea of the inner ear and eyes. It is characterized by mutation causing abnormalities in the collagen within the basement membrane, which has a crucial role in the filtration process of the kidneys. These abnormalities lead to progressive kidney damage and often result in chronic kidney disease. In some cases of Alport syndrome, the abnormal collagen can also affect the cochlea in the inner ear, leading to sensorineural hearing loss. Additionally, changes in the ocular lens, named anterior lenticonus, can occur, causing vision problems. Alport syndrome can manifest differently among individuals, and its severity can vary. Some people may experience mild symptoms, while others may develop more severe kidney problems, including end-stage renal disease, which may need dialysis or kidney transplant. Treatment for Alport syndrome primarily focuses on managing its symptoms and complications. Regular monitoring of kidney function and blood pressure, along with medications to control hypertension, are crucial aspects of the management plan. In cases of severe kidney damage, kidney transplantation may be necessary. As with any medical condition, early detection and intervention can improve results and quality of life for persons with Alport syndrome. Therefore, if there is a family history of the disorder or any concerning symptoms, it is essential to seek medical attention promptly. Genetic testing can help confirm the diagnosis and identify affected family members, allowing for appropriate monitoring and management.
Collapse
Affiliation(s)
- Avanti Adone
- Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Ashish Anjankar
- Biochemistry, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| |
Collapse
|
19
|
Zhang Y, Wang X, Zhou J, Ding J, Wang F. Abnormal mRNA Splicing Effect of COL4A3 to COL4A5 Unclassified Variants. Kidney Int Rep 2023; 8:1399-1406. [PMID: 37441478 PMCID: PMC10334324 DOI: 10.1016/j.ekir.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/30/2023] [Accepted: 04/03/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction Genetic diagnosis of Alport syndrome (AS), which results from pathogenic variants in COL4A3, COL4A4, or COL4A5 genes, is hindered by large numbers of unclassified variants detected using next-generation sequencing (NGS). We examined the impact on splicing of variants of uncertain significance in COL4A3 to COL4A5. Methods Nine unrelated patients with clinical diagnosis or suspicion of AS were enrolled according to the criteria. Their clinical and genetic data were collected. Blood and urine samples were obtained from the patients and their family members. Sanger sequencing was used to confirm the 9 COL4A3 to COL4A5 unclassified variants identified by NGS. COL4A3 to COL4A5 mRNAs from urine were analyzed using targeted reverse transcription polymerase chain reaction and direct sequencing. Results Nine COL4A3 to COL4A5 unclassified variants were found to alter mRNAs splicing. Skipping of an exon or an exon fragment was induced by variants COL4A3 c.828+5G>A; COL4A4 c.3506-13_3528del; and COL4A5 c.451A>G (p. [Ile151Val]), c.2042-9 T>G, c.2689 G>C (p. [Glu897Gln]) and c.1033-10_1033-2delGGTAATAAA. Retention of an intron fragment was caused by variants COL4A3 c.3211-30G>T, and COL4A5 c.4316-20T>A and c.1033-10 G>A, respectively. The 9 families in this study obtained genetic diagnosis of AS, including 3 with autosomal recessive AS and 6 with X-linked AS. Conclusions Our findings demonstrate that urine mRNA analysis facilitates the identification of abnormal splicing of unclassified variants in Alport genes, which provides evidence of routine use of RNA analysis to improve genetic diagnosis of AS.
Collapse
Affiliation(s)
- Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoyuan Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jianmei Zhou
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| |
Collapse
|
20
|
Kim JH, Lim SH, Song JY, Cho MH, Hyun H, Yang EM, Lee JW, Cho MH, Park MJ, Lee JH, Jung J, Yoo KH, Jang KM, Pai KS, Suh JS, Namgoong MK, Chung WY, Kim SJ, Cho EY, Kim KM, Kim NH, Kim M, Paik JH, Kang HG, Ahn YH, Cheong HI. Genotype-phenotype correlation of X-linked Alport syndrome observed in both genders: a multicenter study in South Korea. Sci Rep 2023; 13:6827. [PMID: 37100867 PMCID: PMC10133262 DOI: 10.1038/s41598-023-34053-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/24/2023] [Indexed: 04/28/2023] Open
Abstract
The genotype-phenotype correlation of the X-linked Alport syndrome (XLAS) has been well elucidated in males, whereas it remains unclear in females. In this multicenter retrospective study, we analyzed the genotype-phenotype correlation in 216 Korean patients (male:female = 130:86) with XLAS between 2000 and 2021. The patients were divided into three groups according to their genotypes: the non-truncating group, the abnormal splicing group, and the truncating group. In male patients, approximately 60% developed kidney failure at the median age of 25.0 years, and kidney survival showed significant differences between the non-truncating and truncating groups (P < 0.001, hazard ratio (HR) 2.8) and splicing and truncating groups (P = 0.002, HR 3.1). Sensorineural hearing loss was detected in 65.1% of male patients, while hearing survival periods showed a highly significant difference between the non-truncating and truncating groups (P < 0.001, HR 5.1). In female patients, approximately 20% developed kidney failure at the median age of 50.2 years. The kidney survival was significantly different between the non-truncating and truncating groups (P = 0.006, HR 5.7). Our findings support the presence of genotype-phenotype correlation not only in male patients but also in female patients with XLAS.
Collapse
Affiliation(s)
- Ji Hyun Kim
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, South Korea
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea
| | - Seon Hee Lim
- Department of Pediatrics, Pusan National University Yangsan Children's Hospital and School of Medicine, Yangsan, South Korea
| | - Ji Yeon Song
- Department of Pediatrics, Pusan National University Yangsan Children's Hospital and School of Medicine, Yangsan, South Korea
| | - Myung Hyun Cho
- Department of Pediatrics, Hallym University Sacred Heart Hospital, Anyang, South Korea
| | - HyeSun Hyun
- Department of Pediatrics, College of Medicine, St. Vincent's Hospital, The Catholic University of Korea, Seoul, South Korea
| | - Eun Mi Yang
- Department of Pediatrics, Chonnam National University and School of Medicine, Gwangju, South Korea
| | - Jung Won Lee
- Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, South Korea
| | - Min Hyun Cho
- Department of Pediatrics, Kyungpook National University, School of Medicine, Daegu, South Korea
| | - Min Ji Park
- Department of Pediatrics, Kyungpook National University, School of Medicine, Daegu, South Korea
| | - Joo Hoon Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jiwon Jung
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Kee Hwan Yoo
- Department of Nephrology, Woori Children's Hospital, Seoul, South Korea
| | - Kyung Mi Jang
- Department of Pediatrics, Yeungnam University College of Medicine, Gyeongsan, South Korea
| | - Ki Soo Pai
- Department of Pediatrics, Ajou University School of Medicine, Suwon, South Korea
| | - Jin-Soon Suh
- Department of Pediatrics, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Mee Kyung Namgoong
- Department of Pediatrics, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | | | - Su Jin Kim
- Department of Pediatrics, Inha University College of Medicine, Inha University Hospital, Incheon, South Korea
| | - Eun Young Cho
- Department of Pediatrics, Chungnam National University Hospital, Daejeon, South Korea
| | - Kyung Min Kim
- Department of Pediatrics, Chungnam National University Hospital, Daejeon, South Korea
| | - Nam Hee Kim
- Department of Pediatrics, Inje University Ilsan Paik Hospital, Goyang, South Korea
| | - Minsun Kim
- Department of Pediatrics, Jeonbuk National University Medical School, Jeonju, South Korea
| | - Jin Ho Paik
- Department of Pathology, Seoul National University Bundang Hospital and Seoul National University College of Medicine, Seongnam, South Korea
| | - Hee Gyung Kang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea
- Kidney Research Institute, Medical Research Center, Seoul National University, Seoul, South Korea
| | - Yo Han Ahn
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea.
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea.
- Kidney Research Institute, Medical Research Center, Seoul National University, Seoul, South Korea.
| | - Hae Il Cheong
- Department of Pediatrics, Seoul Red Cross Hospital, Seoul, South Korea.
| |
Collapse
|
21
|
Zhang H, Wang F, Xiao H. Combined Alport syndrome, Klinefelter syndrome and Fanconi syndrome in a Chinese boy. Nephrology (Carlton) 2023; 28:272-275. [PMID: 36878861 DOI: 10.1111/nep.14152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/19/2023] [Accepted: 02/20/2023] [Indexed: 03/08/2023]
Abstract
Alport syndrome (AS) is a progressive renal disease characterized by hematuria and progressive renal failure. X-linked dominant (XLAS) is the major inheritance form, accounting for almost 80% of the cases, caused by mutations in COL4A5 genes. Klinefelter syndrome (KS) is the most common genetic cause of human male gonadal dysgenesis. AS and KS are both rare disease, there are only three cases of combined AS and KS in the literatures. Fanconi syndrome (FS) caused by AS is also very rare. We report here the first case combined AS, KS and FS in a Chinese boy. We suggest that the severe renal phenotype and FS might be due to the two homozygous COL4A5 variants in our boy, and cases of AS combined KS will be good research objects for X chromosome inactivation.
Collapse
Affiliation(s)
- Hongwen Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
| | - Huijie Xiao
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
| |
Collapse
|
22
|
Gregorio VD, Caparali B, Shojaei A, Ricardo S, Barua M. Alport Syndrome: Clinical Spectrum and Therapeutic Advances. Kidney Med 2023; 5:100631. [PMID: 37122389 PMCID: PMC10131117 DOI: 10.1016/j.xkme.2023.100631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023] Open
Abstract
Alport syndrome is a hereditary disorder characterized by kidney disease, ocular abnormalities, and sensorineural hearing loss. Work in understanding the cause of Alport syndrome and the molecular composition of the glomerular basement membrane ultimately led to the identification of COL4A3, COL4A4 (both on chromosome 2q36), and COL4A5 (chromosome Xq22), encoding the α3, α4, and α5 chains of type IV collagen, as the responsible genes. Subsequent studies suggested that autosomal recessive Alport syndrome and males with X-linked Alport syndrome have more severe disease, whereas autosomal dominant Alport syndrome and females with X-linked Alport syndrome have more variability. Variant type is also influential-protein-truncating variants in autosomal recessive Alport syndrome or males with X-linked Alport syndrome often present with severe symptoms, characterized by kidney failure, extrarenal manifestations, and lack of the α3-α4-α5(IV) network. By contrast, mild-moderate forms from missense variants display α3-α4-α5(IV) in the glomerular basement membrane and are associated with protracted kidney involvement without extrarenal manifestations. Regardless of type, therapeutic intervention for kidney involvement is focused on early initiation of angiotensin-converting enzyme inhibitors. There are several therapies under investigation including sodium/glucose cotransporter 2 inhibitors, aminoglycoside analogs, endothelin type A antagonists, lipid-modifying drugs, and hydroxychloroquine, although targeting the underlying defect through gene therapy remains in preclinical stages.
Collapse
|
23
|
Borza DB, Abrahamson DR, Gross O, Savige J. Editorial: Collagen IV nephropathies: Alport syndrome and beyond. Front Med (Lausanne) 2022; 9:1039949. [PMID: 36250080 PMCID: PMC9562859 DOI: 10.3389/fmed.2022.1039949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 09/20/2022] [Indexed: 12/05/2022] Open
Affiliation(s)
- Dorin-Bogdan Borza
- Department of Microbiology, Immunology and Physiology, School of Medicine, Meharry Medical College, Nashville, TN, United States
- *Correspondence: Dorin-Bogdan Borza
| | - Dale R. Abrahamson
- Department of Cell Biology and Physiology and the Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, United States
| | - Oliver Gross
- Department of Nephrology and Rheumatology, University Medical Center Goettingen, Goettingen, Germany
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
24
|
Gibson JT, de Gooyer M, Huang M, Savige J. A systematic review of pathogenic COL4A5 variants and proteinuria in women and girls with X-linked Alport syndrome. Kidney Int Rep 2022; 7:2454-2461. [DOI: 10.1016/j.ekir.2022.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/17/2022] Open
|
25
|
Gomes AM, Lopes D, Almeida C, Santos S, Malheiro J, Lousa I, Caldas Afonso A, Beirão I. Potential Renal Damage Biomarkers in Alport Syndrome—A Review of the Literature. Int J Mol Sci 2022; 23:ijms23137276. [PMID: 35806283 PMCID: PMC9266446 DOI: 10.3390/ijms23137276] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023] Open
Abstract
Alport syndrome (AS) is the second most common cause of inherited chronic kidney disease. This disorder is caused by genetic variants on COL4A3, COL4A4 and COL4A5 genes. These genes encode the proteins that constitute collagen type IV of the glomerular basement membrane (GBM). The heterodimer COL4A3A4A5 constitutes the majority of the GBM, and it is essential for the normal function of the glomerular filtration barrier (GFB). Alterations in any of collagen type IV constituents cause disruption of the GMB structure, allowing leakage of red blood cells and albumin into the urine, and compromise the architecture of the GFB, inducing inflammation and fibrosis, thus resulting in kidney damage and loss of renal function. The advances in DNA sequencing technologies, such as next-generation sequencing, allow an accurate diagnose of AS. Due to the important risk of the development of progressive kidney disease in AS patients, which can be delayed or possibly prevented by timely initiation of therapy, an early diagnosis of this condition is mandatory. Conventional biomarkers such as albuminuria and serum creatinine increase relatively late in AS. A panel of biomarkers that might detect early renal damage, monitor therapy, and reflect the prognosis would have special interest in clinical practice. The aim of this systematic review is to summarize the biomarkers of renal damage in AS as described in the literature. We found that urinary Podocin and Vascular Endothelial Growth Factor A are important markers of podocyte injury. Urinary Epidermal Growth Factor has been related to tubular damage, interstitial fibrosis and rapid progression of the disease. Inflammatory markers such as Transforming Growth Factor Beta 1, High Motility Group Box 1 and Urinary Monocyte Chemoattractant Protein- 1 are also increased in AS and indicate a higher risk of kidney disease progression. Studies suggest that miRNA-21 is elevated when renal damage occurs. Novel techniques, such as proteomics and microRNAs, are promising.
Collapse
Affiliation(s)
- Ana Marta Gomes
- Nephrology Department, Hospital Centre Vila Nova de Gaia/Espinho, 4434-502 Vila Nova de Gaia, Portugal; (A.M.G.); (D.L.); (C.A.)
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
| | - Daniela Lopes
- Nephrology Department, Hospital Centre Vila Nova de Gaia/Espinho, 4434-502 Vila Nova de Gaia, Portugal; (A.M.G.); (D.L.); (C.A.)
| | - Clara Almeida
- Nephrology Department, Hospital Centre Vila Nova de Gaia/Espinho, 4434-502 Vila Nova de Gaia, Portugal; (A.M.G.); (D.L.); (C.A.)
| | - Sofia Santos
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
- ITR, Laboratory for Integrative and Translational Research in Population Health, 4050-313 Porto, Portugal
- Nephrology Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
| | - Jorge Malheiro
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
- ITR, Laboratory for Integrative and Translational Research in Population Health, 4050-313 Porto, Portugal
- Nephrology Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
| | - Irina Lousa
- UCIBIO/REQUIMTE, Laboratory of Biochemistry, Department of Biological Sciences, Faculty Pharmacy, University of Porto, 4050-313 Porto, Portugal;
| | - Alberto Caldas Afonso
- Paediatrics Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal;
- European Rare Kidney Disease Centre (ERKNET)—Universitary Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
| | - Idalina Beirão
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
- ITR, Laboratory for Integrative and Translational Research in Population Health, 4050-313 Porto, Portugal
- Nephrology Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
- European Rare Kidney Disease Centre (ERKNET)—Universitary Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
- Correspondence: or ; Tel.: +351-222077500
| |
Collapse
|