Publications by authors named "Pollazzon M"

Pathogenic variants in the gene are often dominant-negative and cause an X-linked form of Cornelia de Lange syndrome (CdLS) with growth retardation and typical facial features. However, rare variants cause a developmental and epileptic encephalopathy (DEE) with intractable early-onset epilepsy that is absent in CdLS. Here we describe an 11-year-old girl with epilepsy, walking disorder, and neurodevelopmental disorder.

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  • * A case study of a 13-year-old girl revealed typical symptoms of the syndrome along with macrocrania, pes cavus, and conjunctival melanosis, and whole-exome sequencing found a new genetic variant.
  • * The study emphasizes phenotypic features associated with Xia-Gibbs syndrome and suggests that eye asymmetry, noted in the patient, may be an overlooked characteristic of the condition.
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  • The study analyzes data from two groups of individuals with DDX3X variations, one from physicians (48 individuals) and the other from caregivers (44 individuals).
  • The results reveal shared symptoms between the two groups, including previously unreported early childhood issues like feeding difficulties and delayed developmental milestones.
  • The discussion emphasizes that both datasets complement each other, highlighting the importance of addressing symptoms such as ADHD, anxiety, and sleep disturbances in affected individuals.
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Activating Signal Cointegrator 1 complex (ASC-1 complex) is a ribonucleoprotein tetramer participating in transcriptional coactivation and RNA processing, consisting of four subunits: ASCC1-ASCC3 and ASC-1. Pathogenic variants in the TRIP4 and ASCC1 genes, encoding the ASC-1 and ASCC1 subunits, were recently described in congenital myopathic conditions without signs of motor neuron involvement, and Spinal Muscular Atrophy-like (SMA-like) phenotype with prenatal bone fractures. We present a novel pathogenic TRIP4 variant in two siblings with severe phenotype and mixed sensory-motor polyneuropathy.

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Introduction: Synaptotagmin 1 (SYT1), the predominant SYT isoform in the central nervous system, likely acts by promoting vesicle docking, deforming the plasma membrane via Ca-dependent membrane penetration.

Case Presentation: Here, we describe a 21-year-old woman harboring a novel variant in the gene, who presents with a complex phenotype, featuring severe intellectual disability, absent speech, behavioral abnormalities, motor stereotypies, dystonic posturing of her hands, a hyperkinetic movement disorder in her childhood, infantile hypotonia, sialorrhea, mild dysmorphic features, epilepsy, peculiar EEG findings, and severe scoliosis.

Discussion: Based on our case and literature review on the 22 previously described patients, we can confirm a complex neurodevelopmental disorder in which, unlike other synaptopathies, epilepsy is present in a subset of cases (including our patient: 5/23, 22%), although characteristic EEG changes are far more common (10/23, 43.

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  • SOX2 disorders can lead to serious congenital conditions like anophthalmia-esophageal-genital syndrome and microphthalmia, with this study focusing on a specific case involving a chromosomal deletion in a 15-week fetus.* -
  • The autopsy revealed multiple abnormalities including bilateral microphthalmia, facial deformities, brain swelling, and lung issues, indicating a complex interplay of malformations stemming from the genetic deletion.* -
  • The findings suggest that the deletion affects the SOX2 gene, crucial for the development of the nervous system and organs, resulting in a range of abnormalities not previously documented in other cases.*
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Split Hand-Foot Malformation (SHFM) is a congenital limb defect characterized by a median cleft of the hands and/or feet due to the absence/hypoplasia of the central rays. It may occur as part of a syndromic condition or as an isolated malformation. The most common of the six genetic loci identified for this condition is correlated to SHFM1 and maps in the 7q21q22 region.

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Objective: We aimed to report on previously unappreciated clinical features associated with -related intellectual disability (ID) syndrome, a rare neurodevelopmental disorder characterized by global developmental delay, intellectual disability, and language delay, with or without autistic features.

Methods: We performed whole-exome sequencing (WES) to molecularly characterize an individual presenting with ID, epilepsy, autism spectrum disorder, behavioral problems, and facial dysmorphisms as major features.

Results: WES allowed us to identify a previously unreported splice site variant, c.

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  • The blood-brain barrier (BBB) regulates the central nervous system and is linked to neurodevelopmental disorders (NDDs), especially in infants with intracerebral hemorrhage (ICH).
  • Researchers identified a rare disease trait in 13 individuals from 8 families due to a genetic variant in the ESAM gene, affecting endothelial cell function and leading to developmental issues.
  • The study highlights the connection between endothelial dysfunction and NDDs, suggesting the emergence of a new category of diseases called "tightjunctionopathies."
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Technological advances in both genome sequencing and prenatal imaging are increasing our ability to accurately recognize and diagnose Mendelian conditions prenatally. Phenotype-driven early genetic diagnosis of fetal genetic disease can help to strategize treatment options and clinical preventive measures during the perinatal period, to plan in utero therapies, and to inform parental decision-making. Fetal phenotypes of genetic diseases are often unique and at present are not well understood; more comprehensive knowledge about prenatal phenotypes and computational resources have an enormous potential to improve diagnostics and translational research.

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Congenital Stationary Night Blindness type 2 (CSNB2) and Aland island Eye Disease (AIED) associated with CACNA1F mutation demonstrate a significant phenotype overlapping. We report two cases with different clinical presentation carrying two novel mutations in CACNA1F gene. Subjects underwent a complete neurophtahlmological examination associated with structural and electrofunctional insight.

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Microcephaly primary hereditary (MCPH) is a congenital disease characterized by nonsyndromic reduction in brain size due to impaired neurogenesis, often associated with a variable degree of intellectual disability (ID). The genetic etiology of MCPH is heterogeneous and comprises more than 20 loci, nearly all following a recessive inheritance pattern. The first causative gene identified, or , encodes a centrosomal protein that modulates chromosome condensation and cell cycle progression.

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Osteocraniostenosis (OCS, OMIM #602361) is a severe, usually lethal condition characterized by gracile bones with thin diaphyses, a cloverleaf-shaped skull and splenic hypo/aplasia. The condition is caused by heterozygous mutations in the gene and is allelic to the non-lethal, dominant disorder Kenny-Caffey syndrome (KCS, OMIM #127000). Here we report two new cases of OCS, including one with a detailed pathological examination.

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The term "arthrogryposis" is used to indicate multiple congenital contractures affecting two or more areas of the body. Arthrogryposis is the consequence of an impairment of embryofetal neuromuscular function and development. The causes of arthrogryposis are multiple, and in newborns, it is difficult to predict the molecular defect as well as the clinical evolution just based on clinical findings.

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Lissencephaly describes a group of conditions characterized by the absence of normal cerebral convolutions and abnormalities of cortical development. To date, at least 20 genes have been identified as involved in the pathogenesis of this condition. Variants in , encoding a protein involved in the regulation of neuronal migration, have been recently described as causative of lissencephaly with a posterior-prevalent involvement of the cerebral cortex and an autosomal dominant pattern of inheritance.

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One of the recently described syndromes emerging from the massive study of cohorts of undiagnosed patients with autism spectrum disorders (ASD) and syndromic intellectual disability (ID) is White-Sutton syndrome (WHSUS) (MIM #616364), caused by variants in the gene (MIM *614787), located on the long arm of chromosome 1 (1q21.3). So far, more than 50 individuals have been reported worldwide, although phenotypic features and natural history have not been exhaustively characterized yet.

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Wiedemann-Steiner syndrome (WDSTS) is a rare autosomal dominant condition caused by heterozygous loss of function variants in the KMT2A (MLL) gene, encoding a lysine N-methyltransferase that mediates a histone methylation pattern specific for epigenetic transcriptional activation. WDSTS is characterized by a distinctive facial phenotype, hypertrichosis, short stature, developmental delay, intellectual disability, congenital malformations, and skeletal anomalies. Recently, a few patients have been reported having abnormal skeletal development of the cervical spine.

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Basel-Vanagaite-Smirin-Yosef syndrome (BVSYS) is an extremely rare autosomal recessive genetic disorder caused by variants in the MED25 gene. It is characterized by severe developmental delay and variable craniofacial, neurological, ocular, and cardiac anomalies. Since 2015, through whole exome sequencing, 20 patients have been described with common clinical features and biallelic variants in MED25, leading to a better definition of the phenotype associated with BVSYS.

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Alazami syndrome (MIM#615071) is a rare developmental disorder caused by biallelic variants in the LARP7 gene. Hallmark features include short stature, global developmental delay, and distinctive facial features. To date, 23 patients from 11 families have been reported in the literature.

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Variations in genes encoding for the enzymes responsible for synthesizing the linker region of proteoglycans may result in recessive conditions known as "linkeropathies". The two phenotypes related to mutations in genes and (encoding for galactosyltransferase I and II respectively) are similar, characterized by short stature, hypotonia, joint hypermobility, skeletal features and a suggestive face with prominent forehead, thin soft tissue and prominent eyes. The most outstanding feature of these disorders is the combination of severe connective tissue involvement, often manifesting in newborns and infants, and skeletal dysplasia that becomes apparent during childhood.

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Biallelic variants in FAT4 are associated with the two disorders, Van Maldergem syndrome (VMS) (n = 11) and Hennekam syndrome (HS) (n= 40). Both conditions are characterized by a typical facial gestalt and mild to moderate intellectual disability, but differ in the occurrence of neonatal hypotonia and feeding problems, hearing loss, tracheal anomalies, and osteopenia in VMS, and lymphedema in HS. VMS can be caused by autosomal recessive variants in DCHS1 as well, and HS can also be caused by autosomal recessive variants in CCBE1 and ADAMTS3.

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Background: Since 2010, array-CGH (aCGH) has been the first-tier test in the diagnostic approach of children with neurodevelopmental disorders (NDD) or multiple congenital anomalies (MCA) of unknown origin. Its broad application led to the detection of numerous variants of uncertain clinical significance (VOUS). How to appropriately interpret aCGH results represents a challenge for the clinician.

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