Publications by authors named "Suzanne M Leal"

Background: Prelingual hearing impairment (HI) is genetically highly heterogenous. Early diagnosis and intervention are essential for psychosocial development. In this study we investigated a consanguineous family from Pakistan with autosomal recessive (AR) non-syndromic sensorineural HI (NSHI).

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  • *This study focused on the genetic causes of HI in the Malian population through whole exome sequencing, uncovering variants in multiple known HI genes and identifying a novel candidate gene, UBFD1.
  • *Results showed that 75% of the examined families had identifiable causes for HI, with many variants being newly identified and a case of digenic inheritance observed.
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Combined oxidative phosphorylation deficiency (COXPD) is a rare multisystem disorder which is clinically and genetically heterogeneous. Genome sequencing identified biallelic variants in individuals from five unrelated families with presentations ranging from Perrault syndrome (primary ovarian insufficiency and sensorineural hearing loss) to severe childhood onset of leukodystrophy, learning disability, microcephaly and retinal dystrophy. Complexome profiling of fibroblasts from affected individuals revealed reduced levels of the small and, a more pronounced reduction of, the large mitochondrial ribosomal subunits.

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While short-read sequencing currently dominates genetic research and diagnostics, it frequently falls short of capturing certain structural variants (SVs), which are often implicated in the etiology of neurodevelopmental disorders (NDDs). Optical genome mapping (OGM) is an innovative technique capable of capturing SVs that are undetectable or challenging-to-detect via short-read methods. This study aimed to investigate NDDs using OGM, specifically focusing on cases that remained unsolved after standard exome sequencing.

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Bilateral perisylvian polymicrogyria is the most common form of regional polymicrogyria within malformations of cortical development, constituting 20% of all malformations of cortical development. Bilateral perisylvian polymicrogyria is characterized by an excessive folding of the cerebral cortex and abnormal cortical layering. Notable clinical features include upper motoneuron dysfunction, dysarthria and asymmetric quadriparesis.

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Bilateral perisylvian polymicrogyria (BPP) is a structural malformation of the cerebral cortex that can be caused by several genetic abnormalities. The most common clinical manifestations of BPP include intellectual disability and epilepsy. Cytoplasmic FMRP-interacting protein 2 (CYFIP2) is a protein that interacts with the fragile X mental retardation protein (FMRP).

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Digital biobanks that integrate genetic data with health data captured by digital sources are used routinely to discover genes, biomarkers, gene–environment interactions and pharmacogenetic relationships across many clinical areas. There remain many opportunities in dermatology to further use biobank data to increase our knowledge about the genetic architecture of skin disease, to resolve disease mechanisms that can be modulated by medical interventions and to discover genetically derived disease relationships that inform on drug repurposing and adverse events. Such knowledge promises to reduce the global burden of skin disease and facilitates the development of tailored medical care.

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Background: This study was designed to identify common genetic susceptibility and shared genetic variants associated with acute radiation-induced toxicity across 4 cancer types (prostate, head and neck, breast, and lung).

Methods: A genome-wide association study meta-analysis was performed using 19 cohorts totaling 12 042 patients. Acute standardized total average toxicity (STATacute) was modelled using a generalized linear regression model for additive effect of genetic variants, adjusted for demographic and clinical covariates (rSTATacute).

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Intellectual disability (ID) and retinal dystrophy (RD) are the frequently found features of multiple syndromes involving additional systemic manifestations. Here, we studied a family with four members presenting severe ID and retinitis pigmentosa (RP). Using genome wide genotyping and exome sequencing, we identified a nonsense variant c.

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  • Polydactyly is a common limb malformation that affects 1.6-10.6 per 1,000 live births, with specific genetic causes identified in various syndromes related to it, and eleven candidate genes linked to the nonsyndromic type.
  • Research focused on four Pakistani families with autosomal recessive nonsyndromic postaxial polydactyly discovered two new genetic mutations in the EFCAB7 gene that correlate with the condition.
  • EFCAB7 is involved in regulating the Hedgehog signaling pathway critical for limb formation, and this study is the first to connect EFCAB7 to human diseases associated with polydactyly.
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Asthma, type 2 diabetes (T2D), and anthropometric measures are correlated complex traits that all have a major genetic component. To investigate the overlap in genetic variants associated with these complex traits. Using United Kingdom Biobank data, we performed univariate association analysis, fine-mapping, and mediation analysis to identify and dissect shared genomic regions associated with asthma, T2D, height, weight, body mass index (BMI), and waist circumference (WC).

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A short report with two affected siblings from consanguineous family born with intellectual disability, motor disability, language deficit, and hearing impairment and found to carry biallelic nonsense variant in KPTN gene known to be associated with KPTN gene related syndrome.

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  • Analysis of imputed genotypes is critical for genome-wide association studies, and a new method incorporating imputation uncertainty via the Substantive Model Compatible Fully Conditional Specification (SMCFCS) can enhance statistical association testing.
  • Simulations showed that unconditional multiple imputation (MI) was computationally expensive and too conservative, while alternatives like Dosage, Mixture of Regression Models (MRM), and MI SMCFCS offered better statistical power and improved accuracy for low-frequency variants.
  • The study concludes that unconditional MI should be avoided for imputed genotypes; instead, Dosage is recommended for variants with minor allele frequency (MAF) below 0.001 and Rsq above 0.3 due to its performance and
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Pathogenic variants in vacuolar protein sorting 13 homolog B () cause Cohen syndrome (CS), a clinically diverse neurodevelopmental disorder. We used whole exome and Sanger sequencing to identify disease-causing variants in a Pakistani family with intellectual disability, microcephaly, facial dysmorphism, neutropenia, truncal obesity, speech delay, motor delay, and insomnia. We identified a novel homozygous nonsense variant c.

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Age-related (AR) hearing loss (HL) is the most common sensory impairment with heritability of 55%. The aim of this study was to identify genetic variants on chromosome X associated with ARHL through the analysis of data obtained from the UK Biobank. We performed association analysis between self-reported measures of HL and genotyped and imputed variants on chromosome X from ∼460,000 white Europeans.

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Exome sequencing of genes associated with heritable thoracic aortic disease (HTAD) failed to identify a pathogenic variant in a large family with Marfan syndrome (MFS). A genome-wide linkage analysis for thoracic aortic disease identified a peak at 15q21.1, and genome sequencing identified a novel deep intronic FBN1 variant that segregated with thoracic aortic disease in the family (LOD score 2.

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Hereditary deafness and retinal dystrophy are each genetically heterogenous and clinically variable. Three small unrelated families segregating the combination of deafness and retinal dystrophy were studied by exome sequencing (ES). The proband of Family 1 was found to be compound heterozygous for NM_004525.

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Age-related (AR) hearing loss (HL) is a prevalent sensory deficit in the elderly population. Several studies showed that common variants increase ARHL susceptibility. Here, we demonstrate that rare-variants play a crucial role in ARHL etiology.

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Background: Childhood hearing impairment (HI) is genetically heterogeneous with many implicated genes, however, only a few of these genes are reported in African populations.

Methods: This study used exome and Sanger sequencing to resolve the possible genetic cause of non-syndromic HI in a Ghanaian family.

Results: We identified a novel variant c.

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Congenital hearing impairment (HI) is a genetically highly heterogeneous disorder in which prompt recognition and intervention are crucial to optimize outcomes. In this study, we used exome sequencing to investigate a large consanguineous Pakistani family with eight affected individuals showing bilateral severe-to-profound HI. This identified a homozygous splice region variant in STX4 (c.

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Article Synopsis
  • The study investigates phenotypic differences among patients with deep-intronic DMD variants, focusing on genetic and clinical characteristics of 30 patients across 22 families.
  • Out of 38 patients with confirmed DMD variants, 19 distinct variants were identified, leading to a variety of conditions including Duchenne muscular dystrophy and Becker muscular dystrophy.
  • It reveals significant variability in disease presentation not only between families but also within families carrying the same genetic variant, highlighting the complexity of deep-intronic DMD variants and the discovery of a new class of these genetic mutations.
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Background: Essential tremor (ET), one of the most common neurological disorders, has a phenotypically heterogeneous presentation characterized by bilateral kinetic tremor of the arms and, in some patients, tremor involving other body regions (e.g., head, voice).

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Orofaciodigital syndrome (OFD) is clinically heterogeneous and is characterized by abnormalities in the oral cavity, facial features, digits, and central nervous system. At least 18 subtypes of the condition have been described in the literature. OFD is caused by variants in several genes with overlapping phenotypes.

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Background: Branchio-otic syndrome (BO) is one of the most common types of syndromic hearing impairment (HI) with an incidence of 1/40,000 globally. It is an autosomal dominant disorder typically characterized by the coexistence of branchial cysts or fistulae, malformations of the external, middle, and inner ears with preauricular pits or tags and a variable degree of HI. Most cases of BO have been reported in populations of European ancestry.

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Genetic epilepsy with febrile seizures plus (GEFS+) is an autosomal dominant disorder with febrile or afebrile seizures that exhibits phenotypic variability. Only a few variants in SCN1A have been previously characterized for GEFS+, in Latin American populations where studies on the genetic and phenotypic spectrum of GEFS+ are scarce. We evaluated members in two multi-generational Colombian Paisa families whose affected members present with classic GEFS+.

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