Publications by authors named "Abhijit Dixit"

Purpose: To quantify the impact of noncanonical FBN1 splice site variants in undiagnosed Marfan syndrome (MFS), a connective tissue disorder associated with skeletal abnormalities and familial thoracic aortic aneurysm disease (FTAAD).

Methods: A systematic analysis of ultrarare FBN1 variants was performed using genome sequencing data from the 100,000 Genomes Project. Variants were annotated with SpliceAI and the significance of enrichment among individuals with FTAAD was assessed using Fisher's exact test.

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Interstitial deletions of 2q32 are typically identified after investigation for developmental delay. Two genes associated with Ehlers Danlos Syndrome (EDS); COL3A1 and COL5A2 associated with vascular EDS and classical EDS respectively, may be incorporated in the region. Although many reports of 2q32 microdeletion patients exist, there is little mention of these genes with only a few reports highlighting features potentially linked with EDS.

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Purpose: We sought to evaluate outcomes for clinical management after a genetic diagnosis from the Deciphering Developmental Disorders study.

Methods: Individuals in the Deciphering Developmental Disorders study who had a pathogenic/likely pathogenic genotype in the DECIPHER database were selected for inclusion ( = 5010). Clinical notes from regional clinical genetics services notes were reviewed to assess predefined clinical outcomes relating to interventions, prenatal choices, and information provision.

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Article Synopsis
  • DNA replication is crucial for cell division and maintaining genetic stability, with the RFC complex playing a key role by loading important proteins onto DNA.
  • While RFC1's involvement in certain disorders is recognized, the impact of RFC2-5 subunits, particularly RFC4, on human genetic diseases remains under-researched.
  • Our study identifies harmful variants in RFC4 linked to a new disorder marked by muscle weakness and hearing issues, showing how these variants disrupt RFC complex formation and ultimately affect DNA replication and cell cycle processes.
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The identification of structural variants (SVs) in genomic data represents an ongoing challenge because of difficulties in reliable SV calling leading to reduced sensitivity and specificity. We prepared high-quality DNA from 9 parent-child trios, who had previously undergone short-read whole-genome sequencing (Illumina platform) as part of the Genomics England 100,000 Genomes Project. We reanalysed the genomes using both Bionano optical genome mapping (OGM; 8 probands and one trio) and Nanopore long-read sequencing (Oxford Nanopore Technologies [ONT] platform; all samples).

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Importance: Early detection and intervention of hearing loss may mitigate negative effects on children's development. Children who were admitted to the neonatal intensive care unit (NICU) as babies are particularly susceptible to hearing loss and risk factors are vital for surveillance.

Design, Setting And Participants: This single-centre retrospective cohort study included data from 142 inborn infants who had been admitted to the NICU in a tertiary regional referral centre.

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Background: The ITPR1 gene encodes the inositol 1,4,5-trisphosphate (IP ) receptor type 1 (IP R1), a critical player in cerebellar intracellular calcium signaling. Pathogenic missense variants in ITPR1 cause congenital spinocerebellar ataxia type 29 (SCA29), Gillespie syndrome (GLSP), and severe pontine/cerebellar hypoplasia. The pathophysiological basis of the different phenotypes is poorly understood.

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Following the diagnosis of a paediatric disorder caused by an apparently de novo mutation, a recurrence risk of 1-2% is frequently quoted due to the possibility of parental germline mosaicism; but for any specific couple, this figure is usually incorrect. We present a systematic approach to providing individualized recurrence risk. By combining locus-specific sequencing of multiple tissues to detect occult mosaicism with long-read sequencing to determine the parent-of-origin of the mutation, we show that we can stratify the majority of couples into one of seven discrete categories associated with substantially different risks to future offspring.

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Aim: To determine congenital and developmental outcomes of children with Unilateral Hearing Loss (UHL) who were admitted to the Neonatal Intensive Care Unit (NICU).

Method: Retrospective, single-site study that followed 25 children with permanent congenital UHL a NICU admission to a NICU of Nottingham University Hospital. Birth and two-year developmental follow-up data were collected.

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Background: Monogenic disorders are estimated to account for 10%-12% of patients with kidney failure. We report the unexpected finding of an unusual uromodulin variant in multiple pedigrees within the British population and demonstrate a shared haplotype indicative of an ancestral variant.

Methods: Probands from 12 apparently unrelated pedigrees with a family history of kidney failure within a geographically contiguous UK region were shown to be heterozygous for a pathogenic variant of c.

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Article Synopsis
  • TAF4 is a key subunit of the TFIID complex involved in starting transcription, and while other subunits are known to be linked to developmental disorders, TAF4 had not previously been recognized as a disease gene.
  • Researchers report on eight individuals with new loss-of-function variants in TAF4, showing symptoms such as intellectual disability, abnormal behavior, and facial differences, which are characteristic of neuro-developmental disorders.
  • The study proposes the term "TAF4-related NDD" (T4NDD) for this condition and highlights its similarities with other disorders linked to TFIID subunits, suggesting a broader category of related conditions known as TAF-opathies.
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The cartilage aggrecan proteoglycan is crucial for both skeletal growth and articular cartilage function. A number of aggrecan (ACAN) gene variants have been linked to skeletal disorders, ranging from short stature to severe chondrodyplasias. Osteochondritis dissecans is a disorder where articular cartilage and subchondral bone fragments come loose from the articular surface.

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Article Synopsis
  • * A study identified 41 patients with this specific mutation, revealing that most present CALs and freckling, while 83% meet the NIH diagnostic criteria for NF1, but there’s a significant absence of neurofibromas and gliomas, with only one documented case of a subcutaneous neurofibroma.
  • * Learning disabilities
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Article Synopsis
  • The study explores the clinical and genetic aspects of ASXL3-related syndrome, a neurodevelopmental disorder caused by variants in the ASXL3 gene, analyzing 45 new cases alongside previously documented ones.
  • It highlights key characteristics of the syndrome, including significant neurodevelopmental delays and behavioral issues, as well as distinctive facial features observed in affected individuals.
  • The findings aim to enhance clinical management for those with ASXL3-related syndrome and aid in understanding new genetic variants of ASXL3.
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Joubert syndrome is a genetically heterogeneous multisystem disorder typically diagnosed in childhood. Nephronophthisis is the most common renal pathology in Joubert syndrome, and renal failure usually occurs in childhood or in young adults. We report a 61-year-old female diagnosed with -related oculorenal Joubert syndrome, who presented initially with decline in renal function in her 50s.

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CTNND1 encodes the p120-catenin (p120) protein, which has a wide range of functions, including the maintenance of cell-cell junctions, regulation of the epithelial-mesenchymal transition and transcriptional signalling. Due to advances in next-generation sequencing, CTNND1 has been implicated in human diseases including cleft palate and blepharocheilodontic (BCD) syndrome albeit only recently. In this study, we identify eight novel protein-truncating variants, six de novo, in 13 participants from nine families presenting with craniofacial dysmorphisms including cleft palate and hypodontia, as well as congenital cardiac anomalies, limb dysmorphologies and neurodevelopmental disorders.

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Objective: To determine the clinical, radiologic, and molecular characteristics of RNA polymerase III-related leukodystrophy (POLR3-HLD) caused by biallelic pathogenic variants.

Methods: A cross-sectional observational study involving 25 centers worldwide was conducted. Clinical and molecular information was collected on 23 unreported and previously reported patients with POLR3-HLD and biallelic pathogenic variants in .

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Background: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a tumour predisposition syndrome characterised by predisposition to cutaneous and uterine leiomyomata and renal cell carcinoma (RCC).

Objective: To define the clinical findings, molecular genetics, and prognosis in a cohort of 69 families with a fumarate hydratase (FH) pathogenic variant and/or clinical features of HLRCC.

Design, Setting, And Participants: Clinical and molecular findings were obtained for 185 individuals from 69 families from four UK regional genetics clinics.

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Pathogenic variants in the X-linked gene ZC4H2, which encodes a zinc-finger protein, cause an infrequently described syndromic form of arthrogryposis multiplex congenita (AMC) with central and peripheral nervous system involvement. We present genetic and detailed phenotypic information on 23 newly identified families and simplex cases that include 19 affected females from 18 families and 14 affected males from nine families. Of note, the 15 females with deleterious de novo ZC4H2 variants presented with phenotypes ranging from mild to severe, and their clinical features overlapped with those seen in affected males.

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ACTB encodes β-actin, an abundant cytoskeletal housekeeping protein. In humans, postulated gain-of-function missense mutations cause Baraitser-Winter syndrome (BRWS), characterized by intellectual disability, cortical malformations, coloboma, sensorineural deafness, and typical facial features. To date, the consequences of loss-of-function ACTB mutations have not been proven conclusively.

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Objective: Rare genetic disorders resulting in prenatal or neonatal death are genetically heterogeneous, but testing is often limited by the availability of fetal DNA, leaving couples without a potential prenatal test for future pregnancies. We describe our novel strategy of exome sequencing parental DNA samples to diagnose recessive monogenic disorders in an audit of the first 50 couples referred.

Method: Exome sequencing was carried out in a consecutive series of 50 couples who had 1 or more pregnancies affected with a lethal or prenatal-onset disorder.

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The cover image, by Rani A. Bashir et al., is based on the Original Article Lin-Gettig syndrome: Craniosynostosis expands the spectrum of the KAT6B related disorders, DOI: 10.

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Weaver syndrome is a rare overgrowth syndrome with distinct facial features in young children and variable learning disability. Heterozygous missense mutations in EZH2 are present in over 90% of patients with Weaver syndrome but the exact mechanism by which EZH2 mutations cause Weaver syndrome is unknown. We report an 11-year-old boy with a de novo 1.

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We report two patients with sagittal craniosynostosis, hypoplastic male genitalia, agenesis of the corpus callosum, thyroid abnormalities, and dysmorphic features which include short palpebral fissures and retrognathia. The clinical presentation of both patients was initially thought to be suggestive of Lin-Gettig syndrome (LGS), a multiple malformation syndrome associated with craniosynostosis that was initially reported in two brothers in 1990, with a third patient reported in 2003. Our first patient was subsequently found through exome sequencing to have a de novo mutation in KAT6B, c.

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