Comprehensive EHMT1 variants analysis broadens genotype-phenotype associations and molecular mechanisms in Kleefstra syndrome.

The shift to a genotype-first approach in genetic diagnostics has revolutionized our understanding of neurodevelopmental disorders, expanding both their molecular and phenotypic spectra. Kleefstra syndrome (KLEFS1) is caused by EHMT1 haploinsufficiency and exhibits broad clinical manifestations. EHMT1 encodes euchromatic histone methyltransferase-1-a pivotal component of the epigenetic machinery.

De novo heterozygous missense variants in as cause of fetal pleural effusions and progressive fetal hydrops.

Fetal hydrops as detected by prenatal ultrasound usually carries a poor prognosis depending on the underlying aetiology. We describe the prenatal and postnatal clinical course of two unrelated female probands in whom heterozygous missense variants in the planar cell polarity gene were detected using exome sequencing. Using several in vitro assays, we show that the p.

Clinical phenotype of FOXP1 syndrome: parent-reported medical signs and symptoms in 40 individuals.

Background: The first studies on patients with forkhead-box protein P1 (FOXP1) syndrome reported associated global neurodevelopmental delay, autism symptomatology, dysmorphic features and cardiac and urogenital malformations. The aim of this study was to assess the prevalence of congenital abnormalities in an unbiased cohort of patients with FOXP1 syndrome and to document rare complications.

Methods: Patients with FOXP1 syndrome were included, mostly diagnosed via whole-exome sequencing for neurodevelopmental delay.

Elucidating the clinical and molecular spectrum of SMARCC2-associated NDD in a cohort of 65 affected individuals.

Purpose: Coffin-Siris and Nicolaides-Baraitser syndromes are recognizable neurodevelopmental disorders caused by germline variants in BAF complex subunits. The SMARCC2 BAFopathy was recently reported. Herein, we present clinical and molecular data on a large cohort.

Landscape of mSWI/SNF chromatin remodeling complex perturbations in neurodevelopmental disorders.

DNA sequencing-based studies of neurodevelopmental disorders (NDDs) have identified a wide range of genetic determinants. However, a comprehensive analysis of these data, in aggregate, has not to date been performed. Here, we find that genes encoding the mammalian SWI/SNF (mSWI/SNF or BAF) family of ATP-dependent chromatin remodeling protein complexes harbor the greatest number of de novo missense and protein-truncating variants among nuclear protein complexes.

Prenatal testing for imprinting disorders: A laboratory perspective.

Imprinting Disorders (ImpDis) are a group of congenital syndromes associated with up to four different types of molecular disturbances affecting the monoallelic and parent-of-origin specific expression of genomically imprinted genes. Though each ImpDis is characterized by aberrations at a distinct genetic site and a specific set of postnatal clinical signs, there is a broad overlap between several of them. In particular, the prenatal features of ImpDis are non-specific.

Biallelic loss of LDB3 leads to a lethal pediatric dilated cardiomyopathy.

Autosomal dominant variants in LDB3 (also known as ZASP), encoding the PDZ-LIM domain-binding factor, have been linked to a late onset phenotype of cardiomyopathy and myofibrillar myopathy in humans. However, despite knockout mice displaying a much more severe phenotype with premature death, bi-allelic variants in LDB3 have not yet been reported. Here we identify biallelic loss-of-function variants in five unrelated cardiomyopathy families by next-generation sequencing.

Missense variants in ANKRD11 cause KBG syndrome by impairment of stability or transcriptional activity of the encoded protein.

Purpose: Although haploinsufficiency of ANKRD11 is among the most common genetic causes of neurodevelopmental disorders, the role of rare ANKRD11 missense variation remains unclear. We characterized clinical, molecular, and functional spectra of ANKRD11 missense variants.

Methods: We collected clinical information of individuals with ANKRD11 missense variants and evaluated phenotypic fit to KBG syndrome.

Discovering a new part of the phenotypic spectrum of Coffin-Siris syndrome in a fetal cohort.

Purpose: Genome-wide sequencing is increasingly being performed during pregnancy to identify the genetic cause of congenital anomalies. The interpretation of prenatally identified variants can be challenging and is hampered by our often limited knowledge of prenatal phenotypes. To better delineate the prenatal phenotype of Coffin-Siris syndrome (CSS), we collected clinical data from patients with a prenatal phenotype and a pathogenic variant in one of the CSS-associated genes.

Diagnostic Value of a Protocolized In-Depth Evaluation of Pediatric Bone Marrow Failure: A Multi-Center Prospective Cohort Study.

Background: Severe multilineage cytopenia in childhood caused by bone marrow failure (BMF) often represents a serious condition requiring specific management. Patients are at risk for invasive infections and bleeding complications. Previous studies report low rates of identifiable causes of pediatric BMF, rendering most patients with a descriptive diagnosis such as aplastic anemia (AA).

Gene-disease relationship evidence: A clinical perspective focusing on ultra-rare diseases.

The ACMG framework for variant interpretation is well-established and widely used. Although formal guidelines have been published on the establishment of the gene-disease relationships as well, these are not nearly as widely acknowledged or utilized, and implementation of these guidelines is lagging. In addition, for many genes so little information is available that the framework cannot be used in sufficient detail.

Novel diagnostic DNA methylation episignatures expand and refine the epigenetic landscapes of Mendelian disorders.

Overlapping clinical phenotypes and an expanding breadth and complexity of genomic associations are a growing challenge in the diagnosis and clinical management of Mendelian disorders. The functional consequences and clinical impacts of genomic variation may involve unique, disorder-specific, genomic DNA methylation episignatures. In this study, we describe 19 novel episignature disorders and compare the findings alongside 38 previously established episignatures for a total of 57 episignatures associated with 65 genetic syndromes.

Population pharmacokinetics of clonazepam in saliva and plasma: Steps towards noninvasive pharmacokinetic studies in vulnerable populations.

Aim: Traditional studies focusing on the relationship between pharmacokinetics (PK) and pharmacodynamics necessitate blood draws, which are too invasive for children or other vulnerable populations. A potential solution is to use noninvasive sampling matrices, such as saliva. The aim of this study was to develop a population PK model describing the relationship between plasma and saliva clonazepam kinetics and assess whether the model can be used to determine trough plasma concentrations based on saliva samples.

Deficiency of TET3 leads to a genome-wide DNA hypermethylation episignature in human whole blood.

TET3 encodes an essential dioxygenase involved in epigenetic regulation through DNA demethylation. TET3 deficiency, or Beck-Fahrner syndrome (BEFAHRS; MIM: 618798), is a recently described neurodevelopmental disorder of the DNA demethylation machinery with a nonspecific phenotype resembling other chromatin-modifying disorders, but inconsistent variant types and inheritance patterns pose diagnostic challenges. Given TET3's direct role in regulating 5-methylcytosine and recent identification of syndrome-specific DNA methylation profiles, we analyzed genome-wide DNA methylation in whole blood of TET3-deficient individuals and identified an episignature that distinguishes affected and unaffected individuals and those with mono-allelic and bi-allelic pathogenic variants.