In silico, in vitro and ex vivo characterization of cystic fibrosis transmembrane conductance regulator pathogenic variants localized in the fourth intracellular loop and their rescue by modulators.

Background And Purpose: Cystic fibrosis (CF) is due to loss-of-function variants of the CF transmembrane conductance regulator (CFTR) channel. The most effective treatment for people with CF carrying the F508del mutation is the triple combination of elexacaftor-tezacaftor-ivacaftor (ETI). ETI can correct the underlying defect(s) in other CFTR mutants.

Chromosomal Deletion Involving ANKRD26 Leads to Expression of a Fusion Protein Responsible for ANKRD26-Related Thrombocytopenia.

ANKRD26-related thrombocytopenia (ANKRD26-RT) is characterized by lifelong mild to moderate thrombocytopenia. Patients suffer from an increased susceptibility to acute or chronic myeloid leukemia, myelodysplastic syndrome, or chronic lymphocytic leukemia. We described here a patient with inherited thrombocytopenia initially misdiagnosed as immune thrombocytopenic purpura.

Functional Characterization of a Novel Intronic Variant in PIEZO2 in a Recessive Form of Distal Arthrogryposis With Impaired Proprioception and Touch (DAIPT).

Background: Distal arthrogryposis with impaired proprioception and touch (DAIPT) is a rare autosomal recessive neurological disease characterized by progressive alteration of mechanosensation. DAIPT is caused by loss of function variants in the PIEZO2 gene that encodes an ionic channel involved in mechanotransduction signaling. Our study started from the case of an 11-year-old boy with skeletal and neuromuscular features suggestive of DAIPT.

Case Report: Beyond type 1 diabetes: a case of delayed MODY1 diagnosis and successful transition to sulfonylurea therapy.

Maturity-onset diabetes of the young (MODY) is a rare, genetically heterogeneous form of diabetes characterized by early-onset dysglycaemia, typically before 25 years of age, and autosomal dominant inheritance. Among the different forms of MODY, HNF4A-MODY (MODY1) is caused by mutations in the gene, which encodes a transcription factor essential for glucose metabolism. Here, we describe a novel splicing variant in the gene (c.

A hypomorphic FLVCR2 variant resulting in moderate transport deficiency causes hydranencephaly syndrome with brain calcifications.

FLVCR2 is a highly conserved member of the major facilitator superfamily (MFS), the largest superfamily of solute carriers that are involved in the transport of small molecules across lipid bilayers. The loss of the murine ortholog Mfsd7c, an endothelial transporter in brain blood vessels, causes brain angiogenic growth deficiency and lethality. Recessive FLVCR2 variants cause proliferative vasculopathy and hydranencephaly-hydrocephaly syndrome (PVHH), also known as Fowler syndrome.

Interplay between ALK2 mutant receptor and autophagy signaling regulates receptor stability and its chondrogenic functions.

Heterozygous mutations in the Bone morphogenetic protein (BMP) type I receptor ACVR1, encoding activin-like kinase 2 (ALK2), underlie all cases of the rare genetic musculoskeletal disorder Fibrodysplasia Ossificans Progressiva (FOP). The most commonly found mutant ALK2 p.R206H receptor variant exhibits loss of auto inhibition of BMP signaling and can be activated by Activins, while wild-type receptors remain unresponsive.

Derivation of the IGGi006-A stem cell line from a patient with CAPRIN1 haploinsufficiency.

CAPRIN1 gene encodes a RNA-binding protein, abundant in the brain where it plays a crucial role, regulating the transport and translation of mRNAs of synaptic proteins.CAPRIN1 haploinsufficiency causes a neurodevelopmental disorder characterized by language impairment/speech delay, intellectual disability, attention deficit, hyperactivity disorder, and autism spectrum disorder. To understand the pathogenesis of this disorder and in view of future treatment, we generated human induced pluripotent stem cells (iPSCs) from a patient carrying the c.

Hearing loss predictive model in fibrodysplasia ossificans progressiva from a national referral center: developing an hearing loss predictive model.

Fibrodysplasia ossificans progressiva (FOP) is the most dramatic form of progressive heterotopic ossification of soft tissues. Hearing impairment in FOP patient is a common feature, reported by about 50% of affected patients. However, wide case series considering audiologic features are lacking.

LMX1B haploinsufficiency due to variants in the 5'UTR as a cause of Nail-Patella syndrome.

Nail-Patella syndrome (NPS) is a rare autosomal dominant condition due to haploinsufficiency of LMX1B, caused by loss-of-function variants affecting the coding sequence, or partial/whole deletions of the gene. In here, we describe two familial cases of NPS, carrying novel variants of the LMX1B 5'UTR region (-174C>T and -226G>A). To verify their pathogenic role, we carried out a functional characterization, both by reporter gene assays in heterologous systems and in patient's derived cells.

Antisense oligonucleotides as a precision therapy for developmental and epileptic encephalopathies.

Developmental and epileptic encephalopathies (DEEs) comprise a complex spectrum of neurological disorders characterized by neurodevelopmental delay and early-onset seizures primarily caused by diverse genetic mutations. Traditional treatments have largely been symptomatic, focusing on seizure control without addressing the underlying genetic causes. The advent of gene therapy, particularly through antisense oligonucleotides (ASOs), offers a promising avenue toward targeted therapeutic interventions.

Next Generation Sequencing (NGS) Target Approach for Undiagnosed Dysglycaemia.

Next-generation sequencing (NGS) has revolutionized the field of genomics and created new opportunities for basic research. We described the strategy for the NGS validation of the "dysglycaemia panel" composed by 44 genes related to glucose metabolism disorders (MODY, Wolfram syndrome) and familial renal glycosuria using Ion AmpliSeq technology combined with Ion-PGM. Anonymized DNA of 32 previously genotyped cases with 33 different variants were used to optimize the methodology.

Clinical Consequences and Functional Impact of the Rare S737F CFTR Variant and Its Responsiveness to CFTR Modulators.

S737F is a Cystic Fibrosis (CF) transmembrane conductance regulator (CFTR) missense variant. The aim of our study was to describe the clinical features of a cohort of individuals carrying this variant. In parallel, by exploiting ex vivo functional and molecular analyses on nasal epithelia derived from a subset of S737F carriers, we evaluated its functional impact on CFTR protein as well as its responsiveness to CFTR modulators.

"Pesto" Mutation: Phenotypic and Genotypic Characteristics of Eight GCK/MODY Ligurian Patients.

Maturity Onset Diabetes of the Young (MODY) is a monogenic form of diabetes mellitus (DM) that accounts for around 2-5% of all types of diabetes. Autosomal dominant inheritance in pathogenic variations of 14 genes related to β-cell functions can lead to monogenic types of diabetes. In Italy, GCK/MODY is the most frequent form and it is caused by mutations of the glucokinase (GCK).

Rescue by elexacaftor-tezacaftor-ivacaftor of the G1244E cystic fibrosis mutation's stability and gating defects are dependent on cell background.

Background: Cystic fibrosis is caused by mutations impairing expression, trafficking, stability and/or activity of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. The G1244E mutation causes a severe gating defect that it is not completely rescued by ivacaftor but requires the use of a second compound (a co-potentiator). Recently, it has been proposed that the corrector elexacaftor may act also as a co-potentiator.

An example of parenchymal renal sparing in the context of complex malformations due to a novel mutation in the PBX1 gene.

Introduction: PBX1 encodes the pre-B cell leukemia factor 1, a Three Amino acid Loop Extension (TALE) transcription factor crucial to regulate basic developmental processes. PBX1 loss-of-function variants have been initially described in association with renal malformations in both isolated and syndromic forms.

Case Report: Herein, we report a male infant presenting multiple organ malformations (cleidosternal dysostosis, micrognathia, left lung hypoplasia, wide interatrial defect, pulmonary hypertension, total anomalous pulmonary venous return, intestinal malrotation) and carrying the heterozygous de novo c.

The L467F-F508del Complex Allele Hampers Pharmacological Rescue of Mutant CFTR by Elexacaftor/Tezacaftor/Ivacaftor in Cystic Fibrosis Patients: The Value of the Ex Vivo Nasal Epithelial Model to Address Non-Responders to CFTR-Modulating Drugs.

Loss-of-function mutations of the gene cause cystic fibrosis (CF) through a variety of molecular mechanisms involving altered expression, trafficking, and/or activity of the CFTR chloride channel. The most frequent mutation among CF patients, F508del, causes multiple defects that can be, however, overcome by a combination of three pharmacological agents that improve CFTR channel trafficking and gating, namely, elexacaftor, tezacaftor, and ivacaftor. This study was prompted by the evidence of two CF patients, compound heterozygous for F508del and a minimal function variant, who failed to obtain any beneficial effects following treatment with the triple drug combination.

Fibrodysplasia Ossificans Progressiva: What Have We Achieved and Where Are We Now? Follow-up to the 2015 Lorentz Workshop.

Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare progressive genetic disease effecting one in a million individuals. During their life, patients with FOP progressively develop bone in the soft tissues resulting in increasing immobility and early death. A mutation in the gene was identified as the causative mutation of FOP in 2006.

A case of Fibrodysplasia Ossificans Progressiva associated with a novel variant of the ACVR1 gene.

Background: Fibrodysplasia Ossificans Progressiva (FOP) is a rare autosomal dominant disease characterized by congenital malformation of the great toes and progressive heterotopic ossification of soft tissues leading to cumulative disability. The genetic cause of FOP are mutations in the ACVR1 gene that encodes a type I receptor of Bone Morphogenetic Proteins. The most recurrent mutation in FOP patients is R206H affecting the Glycine-Serine rich domain and causing the hyper-activation of the receptor and the responsivity to the non-canonical ligand, Activin A.

Genotype-Phenotype Correlations in Neurofibromatosis Type 1: A Single-Center Cohort Study.

Neurofibromatosis type 1 (NF1) is a proteiform genetic condition caused by pathogenic variants in and characterized by a heterogeneous phenotypic presentation. Relevant genotype-phenotype correlations have recently emerged, but only few pertinent studies are available. We retrospectively reviewed clinical, instrumental, and genetic data from a cohort of 583 individuals meeting at least 1 diagnostic National Institutes of Health (NIH) criterion for NF1.

Evaluating the Influence of a G-Quadruplex Prone Sequence on the Transactivation Potential by Wild-Type and/or Mutant P53 Family Proteins through a Yeast-Based Functional Assay.

P53, P63, and P73 proteins belong to the P53 family of transcription factors, sharing a common gene organization that, from the P1 and P2 promoters, produces two groups of mRNAs encoding proteins with different N-terminal regions; moreover, alternative splicing events at C-terminus further contribute to the generation of multiple isoforms. P53 family proteins can influence a plethora of cellular pathways mainly through the direct binding to specific DNA sequences known as response elements (REs), and the transactivation of the corresponding target genes. However, the transcriptional activation by P53 family members can be regulated at multiple levels, including the DNA topology at responsive promoters.

Genomic Context and Mechanisms of the Mutation in Fibrodysplasia Ossificans Progressiva.

Basic research in Fibrodysplasia Ossificans Progressiva (FOP) was carried out in the various fields involved in the disease pathophysiology and was important for designing therapeutic approaches, some of which were already developed as ongoing or planned clinical trials. Genetic research was fundamental in identifying the FOP causative mutation, and the astonishing progress in technologies for genomic analysis, coupled to related computational methods, now make possible further research in this field. We present here a review of molecular and cellular factors which could explain why a single mutation, the R206H in the gene, is absolutely prevalent in FOP patients.

Genetic and Acquired Heterotopic Ossification: A Translational Tale of Mice and Men.

Heterotopic ossification is defined as an aberrant formation of bone in extraskeletal soft tissue, for which both genetic and acquired conditions are known. This pathologic process may occur in many different sites such as the skin, subcutaneous tissue, skeletal muscle and fibrous tissue adjacent to joints, ligaments, walls of blood vessels, mesentery and other. The clinical spectrum of this disorder is wide: lesions may range from small foci of ossification to massive deposits of bone throughout the body, typical of the progressive genetically determined conditions such as fibrodysplasia ossificans progressiva, to mention one of the most severe and disabling forms.

P63 modulates the expression of the WDFY2 gene which is implicated in cancer regulation and limb development.

TP63 is a member of the TP53 gene family, sharing a common gene structure that produces two groups of mRNAs' encoding proteins with different N-terminal regions (ΔN and TA isoforms); both transcripts are also subjected to alternative splicing mechanisms at C-terminus, generating a variety of isoforms. p63 is a master regulator of epidermal development and homoeostasis as well as an important player in tumorigenesis and cancer progression with both oncogenic and tumour suppressive roles. A number of studies have aimed at the identification of p63 target genes, allowing the dissection of the molecular pathways orchestrated by the different isoforms.