Publications by authors named "Kempers M"

Article Synopsis
  • ARID1A and ARID1B duplications are linked to Coffin-Siris syndrome, but ARID1B duplications have not been previously associated with a specific clinical phenotype until now.
  • A study analyzed 16 cases of ARID1A and 13 cases of ARID1B duplications, revealing that ARID1A duplications resulted in more severe symptoms, including intellectual disabilities and growth delays, while both groups displayed similar features.
  • The research identified unique DNA methylation patterns in ARID1A duplication patients, which differ from those with loss-of-function variants, suggesting the presence of a distinct clinical phenotype for both ARID1A and ARID1B duplications, indicating a new type of
View Article and Find Full Text PDF

Background: Current guidelines indicate that patients with extreme oligozoospermia or azoospermia should be tested for chromosomal imbalances, azoospermia factor (AZF) deletions and/or CFTR variants. For other sperm abnormalities, no genetic diagnostics are recommended.

Objectives: To determine whether exome sequencing (ES) with combined copy number variant (CNV) and single nucleotide variant (SNV) analysis is a reliable first-tier method to replace current methods (validation study), and to evaluate the diagnostic yield after 10 months of implementation (evaluation study).

View Article and Find Full Text PDF

Background: Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder with a high risk for arterial, bowel, and uterine rupture, caused by heterozygous pathogenic variants in . The aim of this cohort study is to provide further insights into the natural history of vEDS and describe genotype-phenotype correlations in a Dutch multicenter cohort to optimize patient care and increase awareness of the disease.

Methods: Individuals with vEDS throughout the Netherlands were included.

View Article and Find Full Text PDF

Our case report documents the first type A aortic dissection in a patient with Kabuki syndrome (KS) and emphasize the need for intensive cardiovascular risk monitoring in patients with KS. It stresses the importance of further research to establish a correlation and awareness for patients with KS.

View Article and Find Full Text PDF

Heritable thoracic aortic diseases (HTAD) are rare pathologies associated with thoracic aortic aneurysms and dissection, which can be syndromic or non-syndromic. They may result from genetic defects. Associated genes identified to date are classified into those encoding components of the (a) extracellular matrix (b) TGFβ pathway and (c) smooth muscle contractile mechanism.

View Article and Find Full Text PDF

To optimize care for children with Marfan syndrome (MFS) in the Netherlands, Dutch MFS growth charts were constructed. Additionally, we aimed to investigate the effect of FBN1 variant type (haploinsufficiency [HI]/dominant negative [DN]) on growth, and compare MFS-related height increase across populations. Height and weight data of individuals with MFS aged 0-21 years were retrospectively collected.

View Article and Find Full Text PDF

Purpose: Heterozygous pathogenic/likely pathogenic (P/LP) variants in the ACTA2 gene confer a high risk for thoracic aortic aneurysms and aortic dissections. This retrospective multicenter study elucidates the clinical outcome of ACTA2-related vasculopathies.

Methods: Index patients and relatives with a P/LP variant in ACTA2 were included.

View Article and Find Full Text PDF

Introduction: The diagnosis of Ehlers-Danlos syndrome is usually based on well-defined diagnostic criteria and the result of DNA investigation. Classical (cEDS) and vascular type (vEDS) are the most prevalent subtypes and are caused by heterozygous pathogenic variants in COL5A1, COL5A2, COL1A1 or, respectively, in COL3A1. We describe 3 cases with contiguous deletions resulting in haploinsufficiency of both genes with relative mild features of connective tissue disease.

View Article and Find Full Text PDF

Vascular Ehlers-Danlos syndrome (vEDS) is a rare genetic disorder clinically characterized by vascular, intestinal and uterine fragility and caused by heterozygous pathogenic variants in the COL3A1 gene. Management of patients with vEDS is difficult due to the unpredictability of the events and clear recommendations on the care of adults and children with vEDS are lacking. Therefore, we aimed to collect data on the current strategy of surveillance and monitoring of vEDS patients by expert centers in continental Europe and Great Britain, as a first step towards a consensus statement.

View Article and Find Full Text PDF

Colorectal cancer (CRC) accounts for approximately 10% of all cancer cases worldwide. Conventional treatment has relied on chemotherapy, radiation therapy and surgery with limited success for patients with metastatic CRC. Toll like receptor (TLR) agonists have garnered attention for their ability to stimulate the innate immune system and consequently stimulate production of proinflammatory cytokines and activate an antitumor T cell response.

View Article and Find Full Text PDF

Neonatal hyperparathyroidism is a rare disease caused by a homozygous inactivating mutation in the calcium sensing receptor gene. It presents early in life with life threatening manifestations of hypercalcemia, if left untreated the condition may be lethal. This is the first case series reported from Sudan.

View Article and Find Full Text PDF

Background: KCNMA1 mutations have recently been associated with a wide range of dysmorphological, gastro-intestinal, cardiovascular, and neurological manifestations.

Methods: Whole exome sequencing was performed in order to identify the underlying pathogenic mutation in two cases presenting with diverse phenotypical manifestations that did not fit into well-known clinical entities.

Results: In an 8-year-old boy presenting with severe aortic dilatation, facial dysmorphism, and overgrowth at birth a de novo p.

View Article and Find Full Text PDF

Thoracic aortic aneurysm and dissection (TAAD) is a major cause of cardiovascular morbidity and mortality. Loss-of-function variants in , encoding the extracellular matrix crosslinking enzyme lysyl oxidase, have been reported to cause familial TAAD. Using a next-generation TAAD gene panel, we identified five additional probands carrying variants, including two missense variants affecting highly conserved amino acids in the catalytic domain and three truncating variants.

View Article and Find Full Text PDF

Turner syndrome (TS) is a chromosomal condition which is associated with an increased prevalence of cardiac morbidity and mortality. In this cross-sectional study, Minnesota-based electrocardiographic (ECG) abnormalities, aortic dimensions, routine- and myocardial strain echocardiographic parameters, and karyotype-cardiac phenotype associations were assessed in girls with TS. In total, 101 girls with TS (0-18 years) were included.

View Article and Find Full Text PDF

Background: Aortic root dilation is a major complication of Marfan syndrome and is one of the most important criteria in establishing the diagnosis. Currently, different echocardiographic nomograms are used to calculate aortic root Z-scores. The aim of the present study was to assess the potential differences in aortic root measurements when aortic root Z-scores were obtained in a cohort of paediatric Marfan patients using several published nomograms.

View Article and Find Full Text PDF

Reversible modification of proteins with linkage-specific ubiquitin chains is critical for intracellular signaling. Information on physiological roles and underlying mechanisms of particular ubiquitin linkages during human development are limited. Here, relying on genomic constraint scores, we identify 10 patients with multiple congenital anomalies caused by hemizygous variants in , encoding a K48/K63 linkage-specific deubiquitylase.

View Article and Find Full Text PDF

Cancer stem cells (CSCs) are located in dedicated niches, where they remain inert to chemotherapeutic drugs and drive metastasis. Although plasticity in the CSC pool is well appreciated, the molecular mechanisms implicated in the regulation of cancer stemness are still elusive. Here, we define a fucosylation-dependent reprogramming of colon cancer cells towards a stem cell-like phenotype and function.

View Article and Find Full Text PDF

Context: Turner syndrome (TS) is a genetic condition that is reported to be associated with a prolonged rate-corrected QT (QTc) interval.

Objectives: To evaluate the prevalence of QTc prolongation in patients with TS, to compare their QTc intervals with healthy controls, and to investigate whether QTc prolongation is associated with a monosomy 45,X karyotype.

Method: Girls (n = 101) and women (n = 251) with TS visiting our center from 2004-2018 were included in this cross-sectional study.

View Article and Find Full Text PDF

We present key points from the updated Dutch-Flemish guideline on comprehensive diagnostics in disorders/differences of sex development (DSD) that have not been widely addressed in the current (inter)national literature. These points are of interest to physicians working in DSD (expert) centres and to professionals who come across persons with a DSD but have no (or limited) experience in this area. The Dutch-Flemish guideline is based on internationally accepted principles.

View Article and Find Full Text PDF

Filamin C (FLNC) variants are associated with cardiac and muscular phenotypes. Originally, FLNC variants were described in myofibrillar myopathy (MFM) patients. Later, high-throughput screening in cardiomyopathy cohorts determined a prominent role for FLNC in isolated hypertrophic and dilated cardiomyopathies (HCM and DCM).

View Article and Find Full Text PDF

Objective: The combination of aortic coarctation (CoA) and bicuspid aortic valve (BAV) is assumed to be associated with a higher risk of ascending aortic dilatation and type A dissection, and current European Society of Cardiology (ESC) guidelines advise therefore to operate at a lower threshold in the presence of CoA. The aim of our study is to evaluate whether the coexistence of CoA in BAV patients is indeed associated with a higher risk of ascending aortic events (AAE).

Methods: In a retrospective study, all adult BAV patients visiting the outpatient clinic of our tertiary care center between February 2003 and February 2019 were included.

View Article and Find Full Text PDF

The ACTA2 gene encodes for smooth muscle specific α-actin, a critical component of the contractile apparatus of the vascular smooth muscle cell. Pathogenic variants in the ACTA2 gene are the most frequently encountered genetic cause of non-syndromic hereditary thoracic aortic disease (HTAD). Although thoracic aortic aneurysm and/or dissection is the main clinical manifestation, a variety of occlusive vascular disease and extravascular manifestations occur in ACTA2-related vasculopathy.

View Article and Find Full Text PDF

Ambiguous genitalia affect 1 in 5,000 live births. Diagnostic procedures can be time-consuming, and often the etiology cannot be established in this group of individuals with differences/disorders of sex development (DSD). We aimed to evaluate the clinical presentation, sex assignment, and diagnostic workup in these patients.

View Article and Find Full Text PDF