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Schack VR, Herlin MK, Pedersen H, Jensen JMB, Færch M, Bundgaard B, Jensen RK, Jensen UB, Christensen R, Andersen GR, Thiel S, Höllsberg P. Novel homozygous CD46 variant with C-isoform expression affects C3b inactivation in atypical hemolytic uremic syndrome. Eur J Immunol 2022; 52:1610-1619. [PMID: 35987516 PMCID: PMC9804674 DOI: 10.1002/eji.202249838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 01/29/2022] [Revised: 05/04/2022] [Accepted: 08/19/2022] [Indexed: 01/09/2023]
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy that may lead to organ failure. Dysregulation of the complement system can cause aHUS, and various disease-related variants in the complement regulatory protein CD46 are described. We here report a pediatric patient with aHUS carrying a hitherto unreported homozygous variant in CD46 (NM_172359.3:c.602C>T p.(Ser201Leu)). In our functional analyses, this variant caused complement dysregulation through three separate mechanisms. First, CD46 surface expression on the patient's blood cells was significantly reduced. Second, stably expressing CD46(Ser201Leu) cells bound markedly less to patterns of C3b than CD46 WT cells. Third, the patient predominantly expressed the rare isoforms of CD46 (C dominated) instead of the more common isoforms (BC dominated). Using BC1 and C1 expressing cell lines, we found that the C1 isoform bound markedly less C3b than the BC1 isoform. These results highlight the coexistence of multiple mechanisms that may act synergistically to disrupt CD46 function during aHUS development.
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Affiliation(s)
| | - Morten K. Herlin
- Department of Clinical GeneticsAarhus University HospitalAarhus NDenmark
| | - Henrik Pedersen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - J. Magnus Bernth Jensen
- Department of Clinical ImmunologyAarhus University HospitalAarhus NDenmark,Department of Molecular MedicineAarhus University HospitalAarhus NDenmark
| | - Mia Færch
- Department of Pediatrics and Adolescent MedicineAarhus University HospitalAarhus NDenmark
| | | | - Rasmus K. Jensen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Uffe B. Jensen
- Department of Clinical GeneticsAarhus University HospitalAarhus NDenmark
| | - Rikke Christensen
- Department of Clinical GeneticsAarhus University HospitalAarhus NDenmark
| | - Gregers R. Andersen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Steffen Thiel
- Department of BiomedicineAarhus UniversityAarhus CDenmark
| | - Per Höllsberg
- Department of BiomedicineAarhus UniversityAarhus CDenmark
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Herlin MK, Le VQ, Højland AT, Ernst A, Okkels H, Petersen AC, Petersen MB, Pedersen IS. Whole-exome sequencing identifies a GREB1L variant in a three-generation family with Müllerian and renal agenesis: a novel candidate gene in Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome. A case report. Hum Reprod 2020; 34:1838-1846. [PMID: 31424080 DOI: 10.1093/humrep/dez126] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/14/2019] [Accepted: 06/19/2019] [Indexed: 11/14/2022] Open
Abstract
The aetiology of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, characterized by uterovaginal agenesis in 46,XX women, remains poorly understood. Since familial occurrences are rare, genetic findings reported so far only apply to a minority of mainly sporadic cases and most studies have not included other family members enabling segregation analysis. Herein, we report on the investigation of a unique three-generation family of two female cousins with MRKH syndrome and unilateral renal agenesis (RA) and two deceased male relatives with RA. We performed whole-exome sequencing (WES) in eight family members leading to the identification of a novel pathogenic (CADD = 33) c.705G>T missense variant in GREB1L, a gene recently identified as a novel cause of RA. Previous reports include several cases of female fetuses with bilateral RA and uterus agenesis, which support GREB1L as an important gene in both kidney and female genital tract development. The pedigree is compatible with autosomal dominant inheritance with incomplete penetrance following a parent-origin-specific manner, which could be due to imprinting. To our knowledge, this is the first investigation of a larger MRKH syndrome pedigree using WES, and we suggest GREB1L as a novel and promising candidate gene in the aetiology of MRKH syndrome.
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Affiliation(s)
- Morten K Herlin
- Department of Clinical Genetics, Aalborg University Hospital, Ladegårdsgade 5, bygning E, 5. Sal, 9000 Aalborg, Denmark.,Pediatrics and Adolescent Medicine, Aarhus University Hospital, Palle Juul-Jensens Blvd. 99, 8200 Aarhus N, Denmark
| | - Vang Q Le
- Section of Molecular Diagnostics, Clinical Biochemistry, Aalborg University Hospital, Reberbansgade 15, 9000 Aalborg, Denmark
| | - Allan T Højland
- Department of Clinical Genetics, Aalborg University Hospital, Ladegårdsgade 5, bygning E, 5. Sal, 9000 Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, 9000 Aalborg, Denmark
| | - Anja Ernst
- Section of Molecular Diagnostics, Clinical Biochemistry, Aalborg University Hospital, Reberbansgade 15, 9000 Aalborg, Denmark
| | - Henrik Okkels
- Section of Molecular Diagnostics, Clinical Biochemistry, Aalborg University Hospital, Reberbansgade 15, 9000 Aalborg, Denmark
| | - Astrid C Petersen
- Department of Pathology, Aalborg University Hospital, Ladegårdsgade 3, 9000 Aalborg, Denmark
| | - Michael B Petersen
- Department of Clinical Genetics, Aalborg University Hospital, Ladegårdsgade 5, bygning E, 5. Sal, 9000 Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, 9000 Aalborg, Denmark
| | - Inge S Pedersen
- Section of Molecular Diagnostics, Clinical Biochemistry, Aalborg University Hospital, Reberbansgade 15, 9000 Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, 9000 Aalborg, Denmark
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