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Gulati A, Bale AE, Dykas DJ, Bia MJ, Danovitch GM, Moeckel GW, Somlo S, Dahl NK. TREX1 Mutation Causing Autosomal Dominant Thrombotic Microangiopathy and CKD-A Novel Presentation. Am J Kidney Dis 2018; 72:895-899. [PMID: 29941221 DOI: 10.1053/j.ajkd.2018.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [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: 12/04/2017] [Accepted: 05/03/2018] [Indexed: 01/20/2023]
Abstract
Renal thrombotic microangiopathy (TMA) involves diverse causes and clinical presentations. Genetic determinants causing alternate pathway complement dysregulation underlie a substantial proportion of cases. In a significant proportion of TMAs, no defect in complement regulation is identified. Mutations in the major mammalian 3' DNA repair exonuclease 1 (TREX1) have been associated with autoimmune and cerebroretinal vasculopathy syndromes. Carboxy-terminal TREX1 mutations that result in only altered localization of the exonuclease protein with preserved catalytic function cause microangiopathy of the brain and retina, termed retinal vasculopathy and cerebral leukodystrophy (RVCL). Kidney involvement reported with RVCL usually accompanies significant brain and retinal microangiopathy. We present a pedigree with autosomal dominant renal TMA and chronic kidney disease found to have a carboxy-terminal frameshift TREX1 variant. Although symptomatic brain and retinal microangiopathy is known to associate with carboxy-terminal TREX1 mutations, this report describes a carboxy-terminal TREX1 frameshift variant causing predominant renal TMA. These findings underscore the clinical importance of recognizing TREX1 mutations as a cause of renal TMA. This case demonstrates the value of whole-exome sequencing in unsolved TMA.
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Affiliation(s)
- Ashima Gulati
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT.
| | - Allen E Bale
- Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Daniel J Dykas
- Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Margaret J Bia
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT
| | - Gabriel M Danovitch
- Division of Nephrology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Gilbert W Moeckel
- Department of Pathology, Yale University School of Medicine, New Haven, CT
| | - Stefan Somlo
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT; Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Neera K Dahl
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT
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Santoro N, Zhang CK, Zhao H, Pakstis AJ, Kim G, Kursawe R, Dykas DJ, Bale AE, Giannini C, Pierpont B, Shaw MM, Leif G, Caprio S. Variant in the glucokinase regulatory protein (GCKR) gene is associated with fatty liver in obese children and adolescents. Hepatology 2012; 55:781-9. [PMID: 22105854 PMCID: PMC3288435 DOI: 10.1002/hep.24806] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/07/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED Recently, the single nucleotide polymorphism (SNP) identified as rs1260326, in the glucokinase regulatory protein (GCKR), was associated with hypertriglyceridemia in adults. Because accumulation of triglycerides in hepatocytes represents the hallmark of steatosis, we aimed to investigate whether this variant might be associated with fatty liver (hepatic fat content, HFF%). Moreover, because recently rs738409 in the PNPLA3 and rs2854116 in the APOC3 were associated with fatty liver, we explored how the GCKR SNP and these two variants jointly influence hepatosteatosis. We studied 455 obese children and adolescents (181 Caucasians, 139 African Americans, and 135 Hispanics). All underwent an oral glucose tolerance test and fasting lipoprotein subclasses measurement by proton nuclear magnetic resonance. A subset of 142 children underwent a fast gradient magnetic resonance imaging to measure the HFF%. The rs1260326 was associated with elevated triglycerides (Caucasians P = 0.00014; African Americans P = 0.00417), large very low-density lipoprotein (VLDL) (Caucasians P = 0.001; African Americans, P = 0.03), and with fatty liver (Caucasians P = 0.034; African Americans P = 0.00002; and Hispanics P = 0.016). The PNPLA3, but not the APOC3 rs2854116 SNP, was associated with fatty liver but not with triglyceride levels. There was a joint effect between the PNPLA3 and GCKR SNPs, explaining 32% of HFF% variance in Caucasians (P = 0.00161), 39.0% in African Americans (P = 0.00000496), and 15% in Hispanics (P = 0.00342). CONCLUSION The rs1260326 in GCKR is associated with hepatic fat accumulation along with large VLDL and triglyceride levels. GCKR and PNPLA3 act together to convey susceptibility to fatty liver in obese youths.
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Affiliation(s)
- Nicola Santoro
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Clarence K. Zhang
- Yale Center for Statistical Genomics and Proteomics, Lund University, University Hospital, Malmoe, Malmoe, Sweden
| | - Hongyu Zhao
- Yale Center for Statistical Genomics and Proteomics, Lund University, University Hospital, Malmoe, Malmoe, Sweden
| | - Andrew J Pakstis
- Department of Genetics, Yale University School of Medicine, Lund University, University Hospital, Malmoe, Malmoe, Sweden
| | - Grace Kim
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Romy Kursawe
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Daniel J. Dykas
- Department of Genetics, Yale University School of Medicine, Lund University, University Hospital, Malmoe, Malmoe, Sweden
| | - Allen E. Bale
- Department of Genetics, Yale University School of Medicine, Lund University, University Hospital, Malmoe, Malmoe, Sweden
| | - Cosimo Giannini
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Bridget Pierpont
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Melissa M. Shaw
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Groop Leif
- Department of Clinical Sciences/Diabetes & Endocrinology and Lund University Diabetes Centre, Lund University, University Hospital, Malmoe, Malmoe, Sweden
| | - Sonia Caprio
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
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Santoro N, Kursawe R, D’Adamo E, Dykas DJ, Zhang CK, Bale AE, Calí AM, Narayan D, Shaw MM, Pierpont B, Savoye M, Lartaud D, Eldrich S, Cushman SW, Zhao H, Shulman GI, Caprio S. A common variant in the patatin-like phospholipase 3 gene (PNPLA3) is associated with fatty liver disease in obese children and adolescents. Hepatology 2010; 52:1281-90. [PMID: 20803499 PMCID: PMC3221304 DOI: 10.1002/hep.23832] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
UNLABELLED The genetic factors associated with susceptibility to nonalcoholic fatty liver disease (NAFLD) in pediatric obesity remain largely unknown. Recently, a nonsynonymous single-nucleotide polymorphism (rs738409), in the patatin-like phospholipase 3 gene (PNPLA3) has been associated with hepatic steatosis in adults. In a multiethnic group of 85 obese youths, we genotyped the PNLPA3 single-nucleotide polymorphism, measured hepatic fat content by magnetic resonance imaging and insulin sensitivity by the insulin clamp. Because PNPLA3 might affect adipogenesis/lipogenesis, we explored the putative association with the distribution of adipose cell size and the expression of some adipogenic/lipogenic genes in a subset of subjects who underwent a subcutaneous fat biopsy. Steatosis was present in 41% of Caucasians, 23% of African Americans, and 66% of Hispanics. The frequency of PNPLA3(rs738409) G allele was 0.324 in Caucasians, 0.183 in African Americans, and 0.483 in Hispanics. The prevalence of the G allele was higher in subjects showing hepatic steatosis. Surprisingly, subjects carrying the G allele showed comparable hepatic glucose production rates, peripheral glucose disposal rate, and glycerol turnover as the CC homozygotes. Carriers of the G allele showed smaller adipocytes than those with CC genotype (P = 0.005). Although the expression of PNPLA3, PNPLA2, PPARγ2(peroxisome proliferator-activated receptor gamma 2), SREBP1c(sterol regulatory element binding protein 1c), and ACACA(acetyl coenzyme A carboxylase) was not different between genotypes, carriers of the G allele showed lower leptin (LEP)(P = 0.03) and sirtuin 1 (SIRT1) expression (P = 0.04). CONCLUSION A common variant of the PNPLA3 gene confers susceptibility to hepatic steatosis in obese youths without increasing the level of hepatic and peripheral insulin resistance. The rs738409 PNPLA3 G allele is associated with morphological changes in adipocyte cell size.
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Affiliation(s)
- Nicola Santoro
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Romy Kursawe
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Ebe D’Adamo
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT,Department of Pediatrics, University of Chieti, Chieti, Italy
| | - Daniel J. Dykas
- Department of Genetics, Yale University School of Medicine, New Haven, CT
| | | | - Allen E. Bale
- Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Anna M. Calí
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Deepak Narayan
- Department of Plastic Surgery, Yale University School of Medicine, New Haven, CT
| | - Melissa M. Shaw
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Bridget Pierpont
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Mary Savoye
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Derek Lartaud
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Samuel Eldrich
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | | | - Hongyu Zhao
- Yale Center for Statistical Genomics and Proteomics, New Haven, CT
| | - Gerald I. Shulman
- Departments of Internal Medicine and Cellular and Molecular Physiology, Howard Hughes Medical Institute, New Haven, CT
| | - Sonia Caprio
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
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Klein RD, Thorland EC, Gonzales PR, Beck PA, Dykas DJ, McGrath JM, Bale AE. A multiplex assay for the detection and mapping of complex glycerol kinase deficiency. Clin Chem 2006; 52:1864-70. [PMID: 16887896 DOI: 10.1373/clinchem.2006.072397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Glycerol kinase deficiency (GKD) is an X-linked recessive disorder that presents in both isolated and complex forms. The contiguous deletion that leads to GKD also commonly affects NR0B1 (DAX1), the gene associated with adrenal hypoplasia congenita, and DMD, the Duchenne muscular dystrophy gene. Molecular testing to delineate this deletion is expensive and has only limited availability. METHODS We designed a multiplex PCR assay for the detection and mapping of a contiguous deletion potentially affecting the IL1RAPL1, NR0B1, GK, and DMD genes in a 29-month-old male patient with GKD. RESULTS Multiplex PCR detected a contiguous deletion that involved the IL1RAPL1, NR0B1, GK, and DMD genes. Although the patient had a creatine kinase concentration within the reference interval, further mapping with PCR revealed that exon 74 was the last intact exon at the 3' end of the DMD gene. CONCLUSIONS Multiplex PCR is an effective and inexpensive way to detect and map the contiguous deletion in cases of complex GKD. The extension of a deletion to include DMD exon 75 in a patient with a creatine kinase concentration within the reference interval suggests that this region of the gene may not be essential for protein function.
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Affiliation(s)
- Roger D Klein
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55901, USA.
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Abstract
PURPOSE This study determines which clinical features predict positive test results among samples submitted for DNA-based diagnostic nevoid basal cell carcinoma syndrome (NBCCS) testing, and further defines the mutational spectrum of the PTCH gene. METHODS DNA was extracted from peripheral blood leukocytes, and polymerase chain reaction products from exons 1 to 23 of the PTCH gene were directly sequenced. Pedigree phenotypic information was obtained by written questionnaire. RESULTS Among 106 presumably unrelated pedigrees, 44 independent mutations were found in 47 families. There were 11 nonsense mutations; 1 in-frame deletion; 17 deletions, 6 insertions, and 1 deletion-insertion that generated frameshifts; 5 splice-site mutations; 1 in-frame duplication; and 2 presumptive missense mutations. Twenty-seven of 46 pedigrees (58.7%) with two or more typical radiographic or pathologic features of NBCCS tested positive for PTCH mutations. Of these, 26 had jaw cysts in combination with other characteristics or neoplasms including basal cell carcinomas, palmar pits, skeletal abnormalities, ocular abnormalities, medulloblastomas, cardiac or ovarian fibromas, calcification of the falx cerebri, polydactyly, cleft lip and/or palate, and agenesis of the corpus callosum or other central nervous system malformations. None of the 13 pedigrees solely affected by multiple or early-onset basal cell carcinomas and none of the four pedigrees with jaw cysts alone had PTCH mutations. CONCLUSIONS Pedigrees with multiple features of NBCCS were most likely to test positive for PTCH mutations. Pedigrees with multiple or early-onset basal cell carcinomas without other features of the disease did not test positive for PTCH mutations.
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Affiliation(s)
- Roger D Klein
- DNA Diagnostic Laboratory, Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA
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