Long-read genome sequencing identifies cryptic structural variants in congenital aniridia cases.

Background: Haploinsufficiency of the transcription factor PAX6 is the main cause of congenital aniridia, a genetic disorder characterized by iris and foveal hypoplasia. 11p13 microdeletions altering PAX6 or its downstream regulatory region (DRR) are present in about 25% of patients; however, only a few complex rearrangements have been described to date. Here, we performed nanopore-based whole-genome sequencing to assess the presence of cryptic structural variants (SVs) on the only two unsolved "PAX6-negative" cases from a cohort of 110 patients with congenital aniridia after unsuccessfully short-read sequencing approaches.

Biallelic intragenic tandem duplication of CPLANE1 in Joubert syndrome: A case report.

Joubert syndrome (JS) is a clinically and genetically heterogeneous genetic disorder. To date, 40 JS-causing genes have been reported and CPLANE1 is one of the most frequently mutated, with biallelic pathogenic missense and truncating variants explaining up to 14% of JS cases. We present a case of JS diagnosed after the identification of a novel biallelic intragenic duplication of exons 20-46 of CPLANE1.

Fine Breakpoint Mapping by Genome Sequencing Reveals the First Large X Inversion Disrupting the Gene in a Patient with Syndromic Cataracts.

Inversions are structural variants that are generally balanced. However, they could lead to gene disruptions or have positional effects leading to diseases. Mutations in the gene cause Nance-Horan syndrome, an X-linked disorder characterised by congenital cataracts and dental anomalies.

Attention Deficit Hyperactivity and Autism Spectrum Disorders as the Core Symptoms of AUTS2 Syndrome: Description of Five New Patients and Update of the Frequency of Manifestations and Genotype-Phenotype Correlation.

Haploinsufficiency of has been associated with a syndromic form of neurodevelopmental delay characterized by intellectual disability, autistic features, and microcephaly, also known as AUTS2 syndrome. While the phenotype associated with large deletions and duplications of is well established, clinical features of patients harboring sequence variants have not been extensively described. In this study, we describe the phenotype of five new patients with pathogenic variants, three of them harboring loss-of-function sequence variants.

Comparison of the diagnostic yield of aCGH and genome-wide sequencing across different neurodevelopmental disorders.

Most consensus recommendations for the genetic diagnosis of neurodevelopmental disorders (NDDs) do not include the use of next generation sequencing (NGS) and are still based on chromosomal microarrays, such as comparative genomic hybridization array (aCGH). This study compares the diagnostic yield obtained by aCGH and clinical exome sequencing in NDD globally and its spectrum of disorders. To that end, 1412 patients clinically diagnosed with NDDs and studied with aCGH were classified into phenotype categories: global developmental delay/intellectual disability (GDD/ID); autism spectrum disorder (ASD); and other NDDs.

Enhanced anti-inflammatory effects of mesenchymal stromal cells mediated by the transient ectopic expression of CXCR4 and IL10.

Background: Mesenchymal stromal cells (MSCs) constitute one of the cell types most frequently used in cell therapy. Although several studies have shown the efficacy of these cells to modulate inflammation in different animal models, the results obtained in human clinical trials have been more modest. Here, we aimed at improving the therapeutic properties of MSCs by inducing a transient expression of two molecules that could enhance two different properties of these cells.

European registration process for Clinical Laboratory Geneticists in genetic healthcare.

Tremendous progress in genetics and genomics led to a wide range of healthcare providers, genetic tests, and more patients who can benefit from these developments. To guarantee and improve the quality of genetic testing, a unified European-based registration for individuals qualified in biomedicine was realized. Therefore a Europe-wide recognition of the profession 'European registered Clinical Laboratory Geneticist (ErCLG)' based on a syllabus of core competences was established which allows for harmonization in professional education.

Fetal Genotyping in Maternal Blood by Digital PCR: Towards NIPD of Monogenic Disorders Independently of Parental Origin.

Purpose: To date, non-invasive prenatal diagnosis (NIPD) of monogenic disorders has been limited to cases with a paternal origin. This work shows a validation study of the Droplet Digital PCR (ddPCR) technology for analysis of both paternally and maternally inherited fetal alleles. For the purpose, single nucleotide polymorphisms (SNPs) were studied with the only intention to mimic monogenic disorders.

Two interstitial rearrangements (16q deletion and 17p duplication) in a child with MR/MCA.

Patients with rare deletions in 16q12 and a duplication of 17p, both interstitial and de novo. Only seven cases have been described with these deletions and none of them presented other chromosomal abnormalities. The proband showed a complex phenotype with features found in patients with dup17p11.

Non-Invasive Prenatal Diagnosis in the Management of Preimplantation Genetic Diagnosis Pregnancies.

Prenatal diagnosis (PD) is recommended in pregnancies after a Preimplantation Genetic Diagnosis (PGD). However, conventional PD entails a risk of fetal loss which makes PGD patients reluctant to undergo obstetric invasive procedures. The presence of circulating fetal DNA in maternal blood allows performing a non-invasive prenatal diagnosis (NIPD) without risk for the pregnancy outcome.

Overview of Five-Years of Experience Performing Non-Invasive Fetal Sex Assessment in Maternal Blood.

Since the discovery of the presence of fetal DNA in maternal blood, non-invasive fetal sex determination has been the test most widely translated into clinical practice. To date there is no agreement between the different laboratories performing such tests in relation to which is the best protocol. As a consequence there are almost as many protocols as laboratories offering the service, using different methodologies and thus obtaining different diagnostic accuracies.

Non-invasive prenatal diagnosis of single-gene disorders from maternal blood.

Prenatal diagnosis (PD) is available for pregnancies at risk of monogenic disorders. However, PD requires the use of invasive obstetric techniques for fetal-sample collection and therefore, involves a risk of fetal loss. Circulating fetal DNA in the maternal bloodstream is being used to perform non-invasive prenatal diagnosis (NIPD).

Noninvasive prenatal diagnosis of monogenic disorders.

Introduction: Since the presence of circulating cell-free fetal DNA (ccffDNA) in maternal peripheral blood was demonstrated in 1997, great efforts have been done in order to use this source of fetal material for noninvasive prenatal diagnosis. The advantage that it represents is avoiding the obstetric invasive procedures required for conventional prenatal diagnosis.

Areas Covered: Efforts are mainly focused on finding the most accurate way to diagnose the most common fetal aneuploidies, paying special attention to trisomy 21.

Noninvasive prenatal diagnosis using ccffDNA in maternal blood: state of the art.

Owing to the risk of fetal loss associated with prenatal diagnostic procedures, the last decade has seen great developments in noninvasive prenatal diagnosis (NIPD). The discovery of circulating cell-free fetal DNA (ccffDNA) in maternal plasma has opened new lines of research in alternative technologies that may facilitate safe diagnosis. Because ccffDNA represents only a small fraction of all DNA present in maternal plasma and it is masked by the background of maternal DNA, the scope of NIPD was, until recently, limited to the study of paternal DNA sequences (i.

Early noninvasive prenatal detection of a fetal CRB1 mutation causing Leber congenital amaurosis.

Purpose: Leber congenital amaurosis (LCA) is one of the most severe inherited retinal dystrophies with the earliest age of onset. Mutations in the Crumbs homologue 1 (CRB1; OMIM 600105) gene explain 10%-24% of cases with LCA depending on the population. The aim of the present work was to study a fetal mutation associated to LCA in maternal plasma by a new methodology in the noninvasive prenatal diagnosis field: the denaturing High Performance Liquid Chromatography (dHPLC).

Prenatal diagnosis in maternal plasma of a fetal mutation causing propionic acidemia.

Prenatal diagnosis (PD) is available to families affected with propionic acidemia (PA), however, it entails a risk of miscarriage. Fetal DNA circulating in maternal blood could allow performing a safe prenatal diagnosis of fetal mutations. Exclusion of the paternal mutation in maternal plasma may avoid conventional PD in cases of recessive disorders such us PA.

New strategy for the prenatal detection/exclusion of paternal cystic fibrosis mutations in maternal plasma.

Background: Since the presence of fetal DNA was discovered in maternal blood, different investigations have focused on non-invasive prenatal diagnosis. The analysis of fetal DNA in maternal plasma may allow the diagnosis of fetuses at risk of cystic fibrosis (CF) without any risk of fetal loss. Here, we present a new strategy for the detection of fetal mutations causing CF in maternal plasma.

MLPA as a screening method of aneuploidy and unbalanced chromosomal rearrangements in spontaneous miscarriages.

Objective: The present study aims to validate multiplex ligation-dependent probe amplification (MLPA) technique with subtelomeric probe mixes as a screening method to detect aneuploidy and unbalanced terminal chromosomal rearrangements in spontaneous abortions (SAs).

Methods: MLPA with P036B and P070 probe mixes was performed on 221 miscarriage DNA samples between the 5th and 24th week of gestation. Cytogenetic culture was attempted on 178 miscarriages.

Clinical presentation of a variant of Axenfeld-Rieger syndrome associated with subtelomeric 6p deletion.

We report a 22-year-old female with a variant of the Axenfeld-Rieger Syndrome (ARS) and discuss its relation with the subtelomeric 6p deletion. An ARS variant has been described in two familial cases of Axenfeld-Rieger Anomaly (ARA) featuring specific extra ocular manifestations-hypertelorism, midface hypoplasia, mild sensorial deafness, hydrocephaly, psychomotor delay and flattened femoral epiphyses. We proposed that this set of characteristics represents a separate syndrome within the ARS.

Detection of a paternally inherited fetal mutation in maternal plasma by the use of automated sequencing.

The discovery of circulating fetal DNA in maternal blood has been an encouraging step forward in the prenatal diagnostic field. It has opened up the possibility of development of a noninvasive method for the genetic analysis of the fetus. Many techniques have been applied to the study of this fetal DNA, but automated sequencing has been seldom used.

Mutational screening of the RP2 and RPGR genes in Spanish families with X-linked retinitis pigmentosa.

Purpose: The X-linked form of retinitis pigmentosa (XLRP) is the most severe type because of its early onset and rapid progression. Five XLRP loci have been mapped, although only two genes, RPGR (for RP3) and RP2, have been cloned. In this study, 30 unrelated XLRP Spanish families were screened to determine the molecular cause of the disease.

Genotype-phenotype variations in five Spanish families with Norrie disease or X-linked FEVR.

Purpose: Norrie disease (OMIM 310600) is a rare X-linked disorder characterized by congenital blindness in males. Approximately 40 to 50% of the cases develop deafness and mental retardation. X-linked familial exudative vitreoretinopathy (XL-FEVR) is a hereditary ocular disorder characterized by a failure of peripheral retinal vascularization.