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Voskarides K, Papagregoriou G, Hadjipanagi D, Petrou I, Savva I, Elia A, Athanasiou Y, Pastelli A, Kkolou M, Hadjigavriel M, Stavrou C, Pierides A, Deltas C. COL4A5 and LAMA5 variants co-inherited in familial hematuria: digenic inheritance or genetic modifier effect? BMC Nephrol 2018; 19:114. [PMID: 29764427 PMCID: PMC5954460 DOI: 10.1186/s12882-018-0906-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 10/25/2017] [Accepted: 01/21/2018] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND About 40-50% of patients with familial microscopic hematuria (FMH) caused by thin basement membrane nephropathy (TBMN) inherit heterozygous mutations in collagen IV genes (COL4A3, COL4A4). On long follow-up, the full phenotypic spectrum of these patients varies a lot, ranging from isolated MH or MH plus low-grade proteinuria to chronic renal failure of variable degree, including end-stage renal disease (ESRD). METHODS Here, we performed Whole Exome Sequencing (WES) in patients of six families, presenting with autosomal dominant FMH, with or without progression to proteinuria and loss of renal function, all previously found negative for severe collagen IV mutations. Hierarchical filtering of the WES data was performed, followed by mutation prediction analysis, Sanger sequencing and genetic segregation analysis. RESULTS In one family with four patients, we found evidence for the contribution of two co-inherited variants in two crucial genes expressed in the glomerular basement membrane (GBM); LAMA5-p.Pro1243Leu and COL4A5-p.Asp654Tyr. Mutations in COL4A5 cause classical X-linked Alport Syndrome, while rare mutations in the LAMA5 have been reported in patients with focal segmental glomerulosclerosis. The phenotypic spectrum of the patients includes hematuria, proteinuria, focal segmental glomerulosclerosis, loss of kidney function and renal cortical cysts. CONCLUSIONS A modifier role of LAMA5 on the background of a hypomorphic Alport syndrome causing mutation is a possible explanation of our findings. Digenic inheritance is another scenario, following the concept that mutations at both loci more accurately explain the spectrum of symptoms, but further investigation is needed under this concept. This is the third report linking a LAMA5 variant with human renal disease and expanding the spectrum of genes involved in glomerular pathologies accompanied by familial hematurias. The cystic phenotype overlaps with that of a mouse model, which carried a Lama5 hypomorphic mutation that caused severely reduced Lama5 protein levels and produced kidney cysts.
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Affiliation(s)
- Konstantinos Voskarides
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, 1, University Avenue, 2109, Nicosia, Cyprus. .,Medical School, University of Cyprus, Nicosia, Cyprus.
| | - Gregory Papagregoriou
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, 1, University Avenue, 2109, Nicosia, Cyprus
| | - Despina Hadjipanagi
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, 1, University Avenue, 2109, Nicosia, Cyprus
| | - Ioanelli Petrou
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, 1, University Avenue, 2109, Nicosia, Cyprus
| | - Isavella Savva
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, 1, University Avenue, 2109, Nicosia, Cyprus
| | - Avraam Elia
- Department of Pediatric Nephrology, Archbishop Makarios III Hospital, Nicosia, Cyprus
| | | | | | - Maria Kkolou
- Department of Nephrology, Larnaca General Hospital, Larnaca, Cyprus
| | | | | | - Alkis Pierides
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, 1, University Avenue, 2109, Nicosia, Cyprus.,Hippocrateon Hospital, Nicosia, Cyprus
| | - Constantinos Deltas
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, 1, University Avenue, 2109, Nicosia, Cyprus. .,College of Medicine, Qatar University, Doha, Qatar.
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Papazachariou L, Demosthenous P, Pieri M, Papagregoriou G, Savva I, Stavrou C, Zavros M, Athanasiou Y, Ioannou K, Patsias C, Panagides A, Potamitis C, Demetriou K, Prikis M, Hadjigavriel M, Kkolou M, Loukaidou P, Pastelli A, Michael A, Lazarou A, Arsali M, Damianou L, Goutziamani I, Soloukides A, Yioukas L, Elia A, Zouvani I, Polycarpou P, Pierides A, Voskarides K, Deltas C. Frequency of COL4A3/COL4A4 mutations amongst families segregating glomerular microscopic hematuria and evidence for activation of the unfolded protein response. Focal and segmental glomerulosclerosis is a frequent development during ageing. PLoS One 2014; 9:e115015. [PMID: 25514610 PMCID: PMC4267773 DOI: 10.1371/journal.pone.0115015] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/17/2014] [Indexed: 12/29/2022] Open
Abstract
Familial glomerular hematuria(s) comprise a genetically heterogeneous group of conditions which include Alport Syndrome (AS) and thin basement membrane nephropathy (TBMN). Here we investigated 57 Greek-Cypriot families presenting glomerular microscopic hematuria (GMH), with or without proteinuria or chronic kidney function decline, but excluded classical AS. We specifically searched the COL4A3/A4 genes and identified 8 heterozygous mutations in 16 families (28,1%). Eight non-related families featured the founder mutation COL4A3-p.(G1334E). Renal biopsies from 8 patients showed TBMN and focal segmental glomerulosclerosis (FSGS). Ten patients (11.5%) reached end-stage kidney disease (ESKD) at ages ranging from 37-69-yo (mean 50,1-yo). Next generation sequencing of the patients who progressed to ESKD failed to reveal a second mutation in any of the COL4A3/A4/A5 genes, supporting that true heterozygosity for COL4A3/A4 mutations predisposes to CRF/ESKD. Although this could be viewed as a milder and late-onset form of autosomal dominant AS, we had no evidence of ultrastructural features or extrarenal manifestations that would justify this diagnosis. Functional studies in cultured podocytes transfected with wild type or mutant COL4A3 chains showed retention of mutant collagens and differential activation of the unfolded protein response (UPR) cascade. This signifies the potential role of the UPR cascade in modulating the final phenotype in patients with collagen IV nephropathies.
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Affiliation(s)
- Louiza Papazachariou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Panayiota Demosthenous
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Myrtani Pieri
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Gregory Papagregoriou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Isavella Savva
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | | | - Michael Zavros
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Kyriakos Ioannou
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Alexia Panagides
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | - Costas Potamitis
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Marios Prikis
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Maria Kkolou
- Department of Nephrology, Larnaca General Hospital, Larnaca, Cyprus
| | | | | | - Aristos Michael
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Akis Lazarou
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Maria Arsali
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Loukas Damianou
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | | | | | - Lakis Yioukas
- Department of Nephrology, Paphos General Hospital, Paphos, Cyprus
| | - Avraam Elia
- Department of Pediatrics, Archbishop Makarios III Hospital, Nicosia, Cyprus
| | - Ioanna Zouvani
- Department of Histopathology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Alkis Pierides
- Department of Nephrology, Hippocrateon Hospital, Nicosia, Cyprus
- * E-mail: (CD); (A. Pierides)
| | - Konstantinos Voskarides
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
- * E-mail: (CD); (A. Pierides)
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