Publications by authors named "Fiona Blanco-Kelly"

Exploring non-coding regions is increasingly gaining importance in the diagnosis of inherited retinal dystrophies. Deep-intronic variants causing aberrant splicing have been identified, prompting the development of antisense oligonucleotides (ASOs) to modulate splicing. We performed a screening of five previously described deep-intronic variants among monoallelic patients with Usher syndrome (USH) or isolated retinitis pigmentosa.

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Article Synopsis
  • * A study identified 25 individuals with new variations in the MSL2 gene, who exhibited NDD symptoms such as developmental delays, coordination problems, and autism spectrum disorder, along with other health concerns.
  • * iPSCs from affected individuals showed reduced MSL2 levels and changes in gene expression, leading to the characterization of a new MSL2-related disorder with unique clinical markers and a specific DNA episignature for diagnosis.
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, one of the most frequently inherited retinal dystrophy (IRD)-causing genes, implies a high phenotypic variability. This study aims to analyze the mutational spectrum in one of the largest cohorts worldwide, and to describe novel pathogenic variants and genotype-phenotype correlations. A study of 220 patients from 103 families recruited from a database of 5000 families.

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Background: APOE is a known genetic contributor to cardiovascular disease, but the differential role alleles play in subclinical atherosclerosis remains unclear.

Methods: The PESA (Progression of Early Subclinical Atherosclerosis) is an observational cohort study that recruited 4184 middle-aged asymptomatic individuals to be screened for cardiovascular risk and multiterritorial subclinical atherosclerosis. Participants were -genotyped, and omics data were additionally evaluated.

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Unlabelled: Chorea can have a wide variety of causes including neurodegenerative, pharmacological, structural, metabolic, infectious, immunologic and paraneoplastic processes. We reviewed the clinical records of patients with apparently sporadic choreic movements and no relevant family history, who presented to our neurology department (Hospital Fundación Jimenez Diaz) between 1991 and 2022. We detected 38 cases of apparent sporadic chorea (ASC); Our analysis revealed 5 cases of genetic chorea (including 3 cases with Huntington's disease) while 6 cases were autoimmune/hematological; 6 drug-related chorea, 5 metabolic-vascular, 5 due to miscellaneous conditions and 4 were of mixed etiology.

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Purpose: To describe the genetic and clinical spectrum of GUCY2D-associated retinopathies and to accurately establish their prevalence in a large cohort of patients.

Design: Retrospective case series.

Methods: Institutional study of 47 patients from 27 unrelated families with retinal dystrophies carrying disease-causing GUCY2D variants from the Fundación Jiménez Díaz hospital dataset of 8000 patients.

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Biallelic pathogenic variants in ALDH1A3 are responsible for approximately 11% of recessively inherited cases of severe developmental eye anomalies. Some individuals can display variable neurodevelopmental features, but the relationship to the ALDH1A3 variants remains unclear. Here, we describe seven unrelated families with biallelic pathogenic ALDH1A3 variants: four compound heterozygous and three homozygous.

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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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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.

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Screening for pathogenic variants in the diagnosis of rare genetic diseases can now be performed on all genes thanks to the application of whole exome and genome sequencing (WES, WGS). Yet the repertoire of gene-disease associations is not complete. Several computer-based algorithms and databases integrate distinct gene-gene functional networks to accelerate the discovery of gene-disease associations.

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Background: KBG syndrome is a highly variable neurodevelopmental disorder and clinical diagnostic criteria have changed as new patients have been reported. Both loss-of-function sequence variants and large deletions (copy number variations, CNVs) involving cause KBG syndrome, but no genotype-phenotype correlation has been reported.

Methods: 67 patients with KBG syndrome were assessed using a custom phenotypical questionnaire.

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Aim: To describe the role of multicolour reflectance images (MCI) in the phenotypic diagnosis of inherited retinal disorders (IRDs).

Methods: A retrospective review of consecutive patients affected by IRDs examined with MCI techniques from January to December 2019 at a tertiary care referral centre. All patients had MCI, fundus autofluorescence and optical coherence tomography taken at the same time point.

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Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy characterized by extensive inter- and intra-familial variability, in which oligogenic interactions have been also reported. Our main goal is to elucidate the role of mutational load in the clinical variability of BBS. A cohort of 99 patients from 77 different families with biallelic pathogenic variants in a BBS-associated gene was retrospectively recruited.

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Purpose: To describe the clinical phenotype and genetic basis of non-syndromic retinitis pigmentosa (RP) in one family and two sporadic cases with biallelic mutations in the transcription factor neural retina leucine zipper (.

Methods: Exome sequencing was performed in one affected family member. Microsatellite genotyping was used for haplotype analysis.

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Purpose: To assess the potential of next-generation sequencing (NGS) technologies to characterize cases diagnosed with autosomal recessive (ar) or sporadic (s) macular dystrophies (ar/sMD) and describe their mutational spectrum.

Methods: A cohort of 1036 families was classified according to their suspected clinical diagnosis-Stargardt disease (STGD), cone and cone-rod dystrophy (CCRD) or other maculopathies (otherMD). Molecular studies included genotyping microarrays, Sanger sequencing, NGS, and sequencing of intronic regions of the ABCA4 gene.

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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.

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Introduction: Biallelic pathogenic RPE65 variants are related to a spectrum of clinically overlapping inherited retinal dystrophies (IRD). Most affected individuals progress to severe disease, with 50% of patients becoming legally blind by 20 years of age. Deeper knowledge of the mutational spectrum and the phenotype-genotype correlation in RPE65-related IRD is needed.

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Heterozygous intragenic loss-of-function mutations of ERF, encoding an ETS transcription factor, were previously reported to cause a novel craniosynostosis syndrome, suggesting that ERF is haploinsufficient. We describe six families harboring heterozygous deletions including, or near to, ERF, of which four were characterized by whole-genome sequencing and two by chromosomal microarray. Based on the severity of associated intellectual disability (ID), we identify three categories of ERF-associated deletions.

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Background: The paired-domain transcription factor paired box gene 6 (PAX6) causes a wide spectrum of ocular developmental anomalies, including congenital aniridia, Peters anomaly and microphthalmia. Here, we aimed to functionally assess the involvement of seven potentially non-canonical splicing variants on missplicing of exon 6, which represents the main hotspot region for loss-of-function variants.

Methods: By locus-specific analysis of using Sanger and/or targeted next-generation sequencing, we screened a Spanish cohort of 106 patients with -related diseases.

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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.

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Alström syndrome (ALMS) is an ultrarare disease with an estimated prevalence lower than 1 in 1,000,000. It is associated with disease-causing mutations in the Alström syndrome 1 () gene, which codifies for a structural protein of the basal body and centrosomes. The symptomatology involves nystagmus, type 2 diabetes mellitus (T2D), obesity, dilated cardiomyopathy (DCM), neurodegenerative disorders and multiorgan fibrosis.

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Purpose: We aimed to establish correlations between the clinical features of a cohort of Usher syndrome (USH) patients with pathogenic variants in MYO7A, type of pathogenic variant, and location on the protein domain.

Methods: Sixty-two USH patients from 46 families with biallelic variants in MYO7A were examined for visual and audiological features. Participants were evaluated based on self-reported ophthalmological history and ophthalmological investigations (computerized visual field testing, best-corrected visual acuity, and ophthalmoscopic and electrophysiological examination).

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Article Synopsis
  • Inherited retinal diseases (IRDs) involve the dysfunction or loss of photoreceptors and show significant clinical and genetic variability; this study aimed to detail the genetic landscape of IRDs in a large cohort of Spanish patients.
  • Over 6,000 individuals from 4,403 families were analyzed, with 53.2% of families genetically characterized, revealing 1,549 likely pathogenic variants across 142 genes, with retinitis pigmentosa being the most common phenotype (55.6% of families).
  • The study identified key genes linked to various IRD forms and highlighted frequent variants, providing valuable insights for genetic diagnosis, counseling, and potential therapies for the Spanish population and related groups.
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