De Novo Balanced Translocations Disrupting the FBN1 Gene Diagnosed by Genome Sequencing: An Uncommon Cause of Marfan Syndrome Modifying Genetic Counseling.

Marfan syndrome (MFS) is a well-characterized rare genetic connective tissue disorder. The features of MFS are primarily skeletal, ocular, and cardiovascular and are mainly caused by single-nucleotide variants (SNVs) in the FBN1 gene (MIM#134797) located on chromosome 15q21.1.

Clinico-biological refinement of BCL11B-related disorder and identification of an episignature: A series of 20 unreported individuals.

Purpose: BCL11B-related disorder (BCL11B-RD) arises from rare genetic variants within the BCL11B gene, resulting in a distinctive clinical spectrum encompassing syndromic neurodevelopmental disorder, with or without intellectual disability, associated with facial features and impaired immune function. This study presents an in-depth clinico-biological analysis of 20 newly reported individuals with BCL11B-RD, coupled with a characterization of genome-wide DNA methylation patterns of this genetic condition.

Methods: Through an international collaboration, clinical and molecular data from 20 individuals were systematically gathered, and a comparative analysis was conducted between this series and existing literature.

Quantification of Female Chimeric Cells in the Tonsils of Male Children and Their Determinants.

The factors influencing mother-to-child cell trafficking and persistence over children's lives have yet to be established. The quantification of maternal microchimerism was previously reported through HLA-based approaches, which introduced bias regarding the tolerogenic environment. We aimed to identify cells of maternal origin irrespective of the HLA repertoire and to ascertain the determinants of microchimeric cells.

Chromoanagenesis, the mechanisms of a genomic chaos.

Designated under the name of chromoanagenesis, the phenomena of chromothripsis, chromanasynthesis and chromoplexy constitute new types of complex rearrangements, including many genomic alterations localized on a few chromosomal regions, and whose discovery over the last decade has changed our perception about the formation of chromosomal abnormalities and their etiology. Although exhibiting specific features, these new catastrophic mechanisms generally occur within a single cell cycle and their emergence is closely linked to genomic instability. Various non-exclusive exogenous or cellular mechanisms capable of generating chromoanagenesis have been evoked.

Outcome of publicly funded nationwide first-tier noninvasive prenatal screening.

Purpose: Noninvasive prenatal screening (NIPS) using cell-free DNA has transformed prenatal care. Belgium was the first country to implement and fully reimburse NIPS as a first-tier screening test offered to all pregnant women. A consortium consisting of all Belgian genetic centers report the outcome of two years genome-wide NIPS implementation.

iPSC reprogramming of fibroblasts from a patient with a Rothmund-Thomson syndrome RTS.

Rothmund-Thomson Syndrome (RTS) is a rare autosomal recessive disease that manifests several clinical features of accelerated aging. These findings include atrophic skin and pigment changes, alopecia, osteopenia, cataracts, and an increased incidence of cancer for patients. Mutations in RECQL4 gene are responsible for cases of RTS.

Current use of noninvasive prenatal testing in Europe, Australia and the USA: A graphical presentation.

Introduction: Noninvasive prenatal testing (NIPT) using cell-free fetal DNA has increasingly been adopted as a screening tool for fetal aneuploidies. Several studies have discussed benefits and limitations of NIPT compared with both ultrasound and invasive procedures, but in spite of some shortcomings NIPT has become extensively used within the last 5 years. This study aims to describe the current use of NIPT in Europe, Australia and the USA.

Chromoanagenesis: a piece of the macroevolution scenario.

Over the last decade, new types of massive and complex chromosomal rearrangements based on the chaotic shattering and restructuring of chromosomes have been identified in cancer cells as well as in patients with congenital diseases and healthy individuals. These unanticipated phenomena are named chromothripsis, chromoanasynthesis and chromoplexy, and are grouped under the term of chromoanagenesis. As mechanisms for rapid and profound genome modifications in germlines and early development, these processes can be regarded as credible pathways for genomic evolution and speciation process.

iPSC line derived from a Bloom syndrome patient retains an increased disease-specific sister-chromatid exchange activity.

Bloom syndrome is characterized by severe pre- and postnatal growth deficiency, immune abnormalities, sensitivity to sunlight, insulin resistance, and a high risk for many cancers that occur at an early age. The diagnosis is established on characteristic clinical features and/or presence of biallelic pathogenic variants in the BLM gene. An increased frequency of sister-chromatid exchanges is also observed and can be useful to diagnose BS patients with weak or no clinical features.

Growth charts in Kabuki syndrome 1.

Kabuki syndrome (KS, KS1: OMIM 147920 and KS2: OMIM 300867) is caused by pathogenic variations in KMT2D or KDM6A. KS is characterized by multiple congenital anomalies and neurodevelopmental disorders. Growth restriction is frequently reported.

De novo and inherited variants in ZNF292 underlie a neurodevelopmental disorder with features of autism spectrum disorder.

Purpose: Intellectual disability (ID) and autism spectrum disorder (ASD) are genetically heterogeneous neurodevelopmental disorders. We sought to delineate the clinical, molecular, and neuroimaging spectrum of a novel neurodevelopmental disorder caused by variants in the zinc finger protein 292 gene (ZNF292).

Methods: We ascertained a cohort of 28 families with ID due to putatively pathogenic ZNF292 variants that were identified via targeted and exome sequencing.

POLR1B and neural crest cell anomalies in Treacher Collins syndrome type 4.

Purpose: Treacher Collins syndrome (TCS) is a rare autosomal dominant mandibulofacial dysostosis, with a prevalence of 0.2-1/10,000. Features include bilateral and symmetrical malar and mandibular hypoplasia and facial abnormalities due to abnormal neural crest cell (NCC) migration and differentiation.

A Novel Chromosomal Translocation Identified due to Complex Genetic Instability in iPSC Generated for Choroideremia.

Induced pluripotent stem cells (iPSCs) have revolutionized the study of human diseases as they can renew indefinitely, undergo multi-lineage differentiation, and generate disease-specific models. However, the difficulty of working with iPSCs is that they are prone to genetic instability. Furthermore, genetically unstable iPSCs are often discarded, as they can have unforeseen consequences on pathophysiological or therapeutic read-outs.

Mosaic complete tetrasomy 21 in a fetus with complete atrioventricular septal defect and minor morphological variations.

Background: Tetrasomy 21 is a very rare aneuploidy which could clinically resemble a Down syndrome. It was most often described in its partial form than complete. We report the prenatal, pathological and genetic characteristics of a fetus with mosaic complete tetrasomy 21.

Reprogramming of Human Peripheral Blood Mononuclear Cell (PBMC) from a patient suffering of a Werner syndrome resulting in iPSC line (REGUi003-A) maintaining a short telomere length.

Werner syndrome (WS) is a rare human autosomal recessive disorder characterized by early onset of aging-associated diseases, chromosomal instability, and cancer predisposition, without therapeutic treatment solution. Major clinical symptoms of WS include common age-associated diseases, such as insulin-resistant diabetes mellitus, and atherosclerosis. WRN, the gene responsible for the disease, encodes a RECQL-type DNA helicase with a role in telomere metabolism.

Report on three additional patients and genotype-phenotype correlation in SLC25A22-related disorders group.

Early infantile epileptic encephalopathy (EIEE) is a heterogeneous group of severe forms of age-related developmental and epileptic encephalopathies with onset during the first weeks or months of life. The interictal electroencephalogram (EEG) shows a "suppression burst" (SB) pattern. The prognosis is usually poor and most children die within the first two years or survive with very severe intellectual disabilities.