Klaas Koop

ORCID: 0000-0003-4027-9723
Publications
Citations
Views
---
Saved
---
About
Contact & Profiles
Research Areas
  • Metabolism and Genetic Disorders
  • Diabetes and associated disorders
  • Renal Diseases and Glomerulopathies
  • Renal Transplantation Outcomes and Treatments
  • Amino Acid Enzymes and Metabolism
  • Lymphatic Disorders and Treatments
  • Genomics and Rare Diseases
  • Childhood Cancer Survivors' Quality of Life
  • Lymphatic System and Diseases
  • Congenital heart defects research
  • Diet and metabolism studies
  • Hematological disorders and diagnostics
  • Chronic Kidney Disease and Diabetes
  • Cellular Mechanics and Interactions
  • Blood disorders and treatments
  • Bartonella species infections research
  • Archaeological Research and Protection
  • Pneumothorax, Barotrauma, Emphysema
  • Clinical Nutrition and Gastroenterology
  • Infectious Aortic and Vascular Conditions
  • Connexins and lens biology
  • Renal and Vascular Pathologies
  • Organ Donation and Transplantation
  • Glycogen Storage Diseases and Myoclonus
  • Abdominal Surgery and Complications

University Medical Center Utrecht
2019-2025

Wilhelmina Children's Hospital
2019-2025

Utrecht University
2025

Institut NeuroMyoGène
2023

Hospices Civils de Lyon
2023

Inserm
2023

University of Florence
2023

Tallinn Health Care College
2023

Université Claude Bernard Lyon 1
2023

Centre National de la Recherche Scientifique
2023

Duchenne's muscular dystrophy is associated with severe, progressive muscle weakness and typically leads to death between the ages of 20 35 years. By inducing specific exon skipping during messenger RNA (mRNA) splicing, antisense compounds were recently shown correct open reading frame DMD gene thus restore dystrophin expression in vitro animal models vivo. We explored safety, adverse-event profile, local dystrophin-restoring effect a single, intramuscular dose an oligonucleotide, PRO051,...

10.1056/nejmoa073108 article EN New England Journal of Medicine 2007-12-26

Proteinuria is a poorly understood feature of many acquired renal diseases. Recent studies concerning congenital nephrotic syndromes and findings in genetically modified mice have demonstrated that podocyte molecules make pivotal contribution to the maintenance selective filtration barrier normal glomerulus. However, it unclear what role play proteinuria This study investigated mRNA protein expression several podocyte-associated Forty-eight patients with various diseases were studied,...

10.1097/01.asn.0000078803.53165.c9 article EN Journal of the American Society of Nephrology 2003-08-01

16p11.2 triplication is a rare chromosomal disorder associated with developmental delay, behavioral abnormalities, and various dysmorphic features. Here, we present case study of four-year-old girl triplication, whose healthy father has smaller duplication that partially overlaps the daughter. She global autism spectrum disorder, anxiety, sensory processing issues, alongside Genetic analysis revealed within region. We used different technical approaches to pinpoint exact genetic architecture...

10.1016/j.ejmg.2025.105013 article EN cc-by European Journal of Medical Genetics 2025-04-01

Galactosemia is a group of hereditary disorders galactose metabolism. A new type galactosemia was discovered, caused by deficiency in mutarotase (GALM), which catalyzes the epimerization between beta- and alpha-D-galactose. All GALM-deficient patients reported literature (n = 44) had abnormal newborn screening (NBS) results or did not receive NBS 2). We present first patient with GALM who negative Netherlands identified at age 1.5 years during broad metabolic because her global developmental...

10.3390/ijns11020025 article EN cc-by International Journal of Neonatal Screening 2025-04-11

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease. Albuminuria risk factor for FSGS and influenced by environmental, genetic, sex-specific factors. Podocytes play central role in the development albuminuria, but precise relationship between early glomerular podocyte-associated damage albuminuria unclear. Furthermore, experimental findings demonstrate sex difference FSGS. We investigated changes male Munich-Wistar-Frömter (MWF) rats, which spontaneously...

10.1152/ajprenal.00457.2007 article EN AJP Renal Physiology 2008-01-17

Undiagnosed and untreated tyrosinemia type 1 (TT1) individuals carry a significant risk for developing liver fibrosis, cirrhosis hepatocellular carcinoma (HCC). Elevated succinylacetone (SA) is pathognomonic TT1 therefore often used as marker newborn screening (NBS). While SA was long considered to be elevated in every patient, here we present recent false-negative screen. A nine-year-old boy presented with HCC cirrhotic liver. Additional tests the underlying cause unexpectedly revealed TT1....

10.3390/ijns9040066 article EN cc-by International Journal of Neonatal Screening 2023-12-04

Dried blood spot succinylacetone (SA) is often used as a biomarker for newborn screening (NBS) tyrosinemia type 1 (TT1). However, false-positive SA results are observed. Elevated may also be due to maleylacetoacetate isomerase deficiency (MAAI-D), which appears clinically insignificant. This study investigated whether urine organic acid (uOA) and quantitative maleic (Q-uMA) analyses can distinguish between TT1 MAAI-D. We reevaluated/measured uOA (GC-MS) and/or Q-uMA (LC-MS/MS) in available...

10.1002/jimd.12669 article EN cc-by-nc Journal of Inherited Metabolic Disease 2023-08-07

Abstract The sodium‐dependent multivitamin transporter that facilitates the uptake of water‐soluble vitamins biotin, pantothenic acid, and vitamin‐like substance lipoate is coded by SLC5A6 gene. Variants in this gene cause a relatively novel treatable metabolic disorder. Here we describe second case. A 17‐month‐old girl presented with hypoglycemia (2.0 mmol/L) severe acidosis (pH 6.87), leading to resuscitation. Her history revealed feeding problems from birth poor weight gain. Metabolic...

10.1002/jmd2.12040 article EN cc-by JIMD Reports 2019-05-28

The Wilson and Jungner (W&J) Andermann criteria are meant to help select diseases eligible for population-based screening. With the introduction of next-generation sequencing (NGS) methods newborn screening (NBS), more inherited metabolic (IMDs) can technically be included, a revision was attempted. This study aimed formulate statements investigate whether those could elaborate on criterion treatability IMDs decide eligibility NBS. An online Delphi started among panel Dutch IMD experts...

10.3390/ijns9040056 article EN cc-by International Journal of Neonatal Screening 2023-10-11

Little is known regarding the composition of interstitial extracellular matrix kidney allografts with deteriorating function. Collagen I, III, and IV, collagen IV alpha3 chain, laminin beta2 chain were investigated in biopsies allografted kidneys chronic cyclosporine A nephrotoxicity (CsAT) (n = 17), rejection (CR) 12), or allograft nephropathy (CAN) 19). alpha-Smooth muscle actin expression was also examined. Normal native used as control samples 11). Biopsy studied routine light microscopy...

10.1097/01.asn.0000077345.81206.00 article EN Journal of the American Society of Nephrology 2003-08-01

Abstract Dynamin plays an essential role in maintaining the structure and function of glomerular filtration barrier. Specifically, dynamin regulates actin cytoskeleton turnover nephrin podocytes, knocking down expression causes proteinuria. Moreover, promoting oligomerization with Bis‐T‐23 restores podocyte reduces proteinuria several animal models chronic kidney disease. Thus, is a promising therapeutic target for treating Here, we investigated pathophysiological under proteinuric...

10.1002/path.5181 article EN cc-by The Journal of Pathology 2018-10-23

Diffuse C4d staining in peritubular capillaries (PTCs) during an acute rejection episode (ARE) is the footprint of antibody-mediated rejection. In current clinical practice, diffuse C4d+ regarded as inferior prognostic sign. This case-control study investigated role mere for graft outcome ARE a well defined cohort similarly ARE-treated patients.All kidney transplant recipients authors' center from January 1, 1995 to December 31, 2005 were reviewed. From these patients, 151 had ARE. Paraffin...

10.2215/cjn.07820910 article EN Clinical Journal of the American Society of Nephrology 2011-04-29

Due to newborn screening for X-linked adrenoleukodystrophy (ALD), and the use of exome sequencing in clinical practice, detection variants unknown significance (VUS) ABCD1 gene is increasing. In these cases, functional tests fibroblasts may help classify a variant as (likely) benign or pathogenic. We sought establish reference ranges ALD patients control subjects with aim helping determine pathogenicity VUS ABCD1. Fibroblasts from 36 male confirmed ALD, 26 healthy 17 individuals without...

10.3390/genes12121930 article EN Genes 2021-11-30
Klaas Koop Weimin Yuan Federico Tessadori Wilmer R. Rodriguez-Polanco Jeremy J. Grubbs and 95 more Bo Zhang Matt Osmond Gail E. Graham Sarah L. Sawyer Erin Conboy Francesco Vetrini Kayla Treat Rafał Płoski Victor Murcia Pienkowski Anna Kłosowska Elizabeth L. Fieg Joel B. Krier Coralie Mallebranche Alban Ziegler Kimberly A. Aldinger Deborah Ritter Ellen F. Macnamara Bonnie Sullivan John Herriges Joseph T. Alaimo Catherine Helbig Colin A. Ellis Clare L. van Eyk Jozef Gécz Daniel J. Farrugia Ikeoluwa Osei‐Owusu Lesley C. Adès Marie-José van den Boogaard Sabine A. Fuchs Jeroen Bakker Karen Duran Zachary Dawson Anika Lindsey Huiyan Huang Dustin Baldridge Gary A. Silverman Barth D. Grant David M. Raizen Maria T. Acosta Margaret P Adam David R. Adams Justin Alvey Laura M. Amendola Ashley Andrews Euan A. Ashley Mahshid S. Azamian Carlos A. Bacino Güney Bademci Ashok Balasubramanyam Dustin Baldridge Jim Bale Michael Bamshad Deborah Barbouth Pinar Bayrak‐Toydemir Anita Beck Alan H. Beggs Edward M. Behrens Gill Bejerano Hugo J. Bellen Jimmy Bennet Beverly Berg-Rood Jonathan A. Bernstein Gerard T. Berry Anna Bican Stephanie Bivona Elizabeth Blue John Bohnsack Devon Bonner Lorenzo D. Botto Brenna Boyd Lauren C. Briere Elly Brokamp Gabrielle Brown Elizabeth A. Burke Lindsay C. Burrage Manish J. Butte Peter H. Byers William E. Byrd John C. Carey Olveen Carrasquillo Thomas Cassini Ta Chen Chang Sirisak Chanprasert Hsiao‐Tuan Chao Gary Clark Terra R. Coakley Laurel A. Cobban Joy D. Cogan Matthew Coggins F. Sessions Cole Heather A. Colley Cynthia M. Cooper Heidi Cope William J. Craigen Andrew B. Crouse

Abstract Rab GTPases are important regulators of intracellular vesicular trafficking. RAB5C is a member the GTPase family that plays an role in endocytic pathway, membrane protein recycling and signaling. Here we report on 12 individuals with nine different heterozygous de novo variants RAB5C. All but one patient missense (n = 9) exhibited macrocephaly, combined mild-to-moderate developmental delay. Patients loss function 2) had apparently more severe clinical phenotype refractory epilepsy...

10.1093/hmg/ddad130 article EN cc-by-nc Human Molecular Genetics 2023-08-08

Background and ObjectivesHeterozygous variants in RAR-related orphan receptor B (RORB) have recently been associated with susceptibility to idiopathic generalized epilepsy. However, few reports published so far describing pathogenic of this gene patients epilepsy intellectual disability (ID). In study, we aimed delineate the phenotype RORB provide arguments favor pathogenicity variants.MethodsThrough an international collaboration, analyzed seizure characteristics, EEG data, genotypes a...

10.1212/wnl.0000000000207945 article EN Neurology 2023-12-22

A 25-year-old man was admitted with a long history of weakness and wasting. In fact, he said “was born—and fell ill.” He claimed to be still unmarried as result his illness. One year earlier had been pain in left hip. Despite several hospital admissions, an explanation for illness not found. He wasted, pale, slightly jaundiced. His chest, abdomen, extremities appeared normal. forehead maxillae were prominent, this prompted us take x-ray skull. The (Figure 1A) showed hair-on-end pattern...

10.4269/ajtmh.12-0498 article EN other-oa American Journal of Tropical Medicine and Hygiene 2013-04-03

Pellagra is a disease of poverty that treatable but easily overlooked. The caused by deficiency niacin and clinically characterized the triad dermatitis, diarrhoea dementia. We describe two cases pellagra in Malawian district hospital discuss pathogenesis, clinical manifestations treatment disease.

10.1258/td.2012.120155 article EN Tropical Doctor 2012-07-01

A 2-year-old girl presented with recurrent episodes of pharyngitis and a perineal rash. During the first episode, course antibiotics resulted in quick resolution symptoms. Yet few days later, her symptoms had recurred she was referred to our clinic. She febrile, lips were red fissured (figure 1A), tonsils enlarged red, pronounced rash 1 …

10.1136/archdischild-2013-304564 article EN Archives of Disease in Childhood 2013-08-19
Coming Soon ...