Publications by authors named "Adrien Bloch"

Background: Accurate interpretation of genetic variants still represents a major challenge. According to current recommendations from the American College of Medical Genetics and Genomics (ACMG), variant interpretation relies on a comprehensive analysis including, among others, computational data for prediction of variant pathogenicity. However, the predictive accuracy of in silico tools is often limited, and results are frequently inconsistent.

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  • - The study compares genotypes between pediatric cardiomyopathy (pCM) and adult-onset cardiomyopathy (aCM) to understand why pCM has earlier onset and differs in severity.
  • - Analysis of 253 pCM patients revealed a higher rate of genetic variants, particularly in restrictive pCM, and identified critical risk factors for adverse outcomes such as early diagnosis and presence of multiple variants.
  • - Genetic testing not only clarified the genetic basis for pCM but also enhanced genetic counseling for families, resulting in cases of prenatal diagnosis.
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  • SCN5A gene variants are linked to various cardiac electrical disorders, but they can also result in complex phenotypes like overlap syndromes, which haven't been thoroughly studied.
  • The study analyzed DNA from over 13,500 patients with a focus on those carrying pathogenic SCN5A variants, finding that most were tied to well-defined conditions like Brugada syndrome and long QT syndrome.
  • About 19% of the variants were associated with complex phenotypes, and only a small number (8 out of 9,960 patients) showed a potential link to dilated cardiomyopathies (DCM), suggesting it's a rare association.
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  • KCNQ1 mutations are linked to long QT syndrome (LQT) and increase the risk of life-threatening heart arrhythmias, with distinct impacts based on whether the mutations are heterozygous or homozygous.
  • This study analyzed data from 789 individuals with KCNQ1 variants to compare QTc duration and cardiac event risks among three groups: JLNS patients, heterozygous JLNS variant carriers, and heterozygous non-JLNS variant carriers.
  • Findings revealed that heterozygous JLNS variant carriers had a significantly lower risk of cardiac events compared to non-JLNS carriers, with specific genetic factors identified as influencing these risks.
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  • Genetic testing is increasingly recognized as a valuable method for evaluating non-ischaemic sudden cardiac arrest (SCA), particularly in cases with unclear causes.
  • Among 66 patients studied, approximately 32% had genetic variants, with a small portion identified as pathogenic.
  • The findings suggest that genetic testing is useful even in patients without noticeable symptoms, potentially guiding future treatment and management strategies.
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  • Biallelic variants in the ALPK3 gene are linked to severe cardiomyopathy in children, while heterozygous variants in adults can lead to hypertrophic cardiomyopathy (HCM).
  • A study involving genetic testing of 16,183 cardiomyopathy cases found 36 patients with null ALPK3 variants, highlighting the gene's significance in HCM.
  • The research emphasizes the need for ALPK3 screening in patients with idiopathic HCM due to its strong association with the condition, particularly in pediatric cases presenting severe outcomes.
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Background: The efficacy of beta-blocker treatment in type 3 long QT syndrome (LQT3) remains debated.

Objectives: The purpose of this study was to test the hypothesis that beta-blocker use is associated with cardiac events (CEs) in a French cohort of LQT3 patients.

Methods: All patients with a likely pathogenic/pathogenic variant in the SCN5A gene (linked to LQT3) were included and followed-up.

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Background: Titinopathies are caused by mutations in the titin gene (). Titin is the largest known human protein; its gene has the longest coding phase with 364 exons. Titinopathies are very complex neuromuscular pathologies due to the variable age of onset of symptoms, the great diversity of pathological and muscular impairment patterns (cardiac, skeletal muscle or mixed) and both autosomal dominant and recessive modes of transmission.

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Primary hypertrophic osteoarthropathy (PHO), or pachydermoperiostosis, is characterized by a clinical association including digital clubbing, periostosis and pachydermia. SLCO2A1 and HPGD genes are both responsible for PHO. The pathology is classically defined as an autosomal recessive disorder with clinical variability ranging from a mild to more severe phenotype.

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Purpose: We studied the quality differences between the different hypo-osmotic swelling test (HOST) classes, as measured by criteria of DNA fragmentation, DNA decondensation, and nuclear architecture. The aim was to find particular HOST classes associated with good-quality metrics, which may be potentially used in ICSI (intra-cytoplasmic sperm injection).

Methods: Ten patients from the Department of Reproductive Medicine at Tenon Hospital (Paris, France) were included.

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The molecular study of mitochondrial diseases, essential for diagnosis, is special due to the dual genetic origin of these pathologies: mitochondrial DNA and nuclear DNA. Complete mtDNA sequencing still remains the first line diagnostic test followed if negative, by resequencing panels of several hundred mitochondrially-encoded nuclear genes. This strategy, with an initial entire mtDNA sequencing, is currently justified by the presence of nuclear mitochondrial DNA sequences (NUMTs) in the nuclear genome.

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Background: Wilson disease is an autosomal recessive metabolic disorder resulting from accumulation of excess copper especially in the liver and brain. This disease is mainly characterized by hepatic disorders and less frequently by neuro-psychiatric disturbances. This recessive disease is due to mutation in ATP7B, which codes for an ATPase involved in copper-transport across the plasma membrane.

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Background: The prevalence of chromosomal translocations is 1/500 in the general population. While in the vast majority of cases, carriers have a normal phenotype; they can present with difficulty conceiving due to the presence of a proportion of unbalanced gametes as a consequence of abnormal chromosomal segregation during meiosis. Since complex translocations involve three or more chromosomes, meiotic segregation leads to a greater number of possible combinations which effectively complicate both their study and therapeutic care.

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