Improving diagnostic yield in rare diseases through phenotypic-driven approaches

NDD. Family-based (trio) exome sequencing has become the standardized method for identifying genetic etiologies that cause neurodevelopmental disorders. De novo variants have been responsible for the majority of pathogenic genetic findings, although the landscape of genetic disorders overall is highly heterogeneous. In a recently published study, the authors assessed variant classification to identify new molecular diagnoses and factors influencing the likelihood of receiving a diagnosis. The study reported a diagnostic yield of over 41%, highlighting 60 new genes associated with developmental disorders. The authors also emphasized the importance of structured and detailed phenotypic information for improving variant interpretation. This blog post provides a brief review of their publication in the context of improving diagnostic yield using a phenotypically driven approach in rare diseases.

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Expanding the spectrum of SNAREopathies – STX1A in epilepsy and neurodevelopmental disorders

SNAREopathies. This post continues the series on SNAREopathies, a group of neurodevelopmental conditions caused by variants in genes encoding components that form the SNARE complex and regulatory proteins. As previously described, the SNARE complex is the molecular machinery driving synaptic vesicle release in the presynapse, which enables communication between neurons. Here, we expand the discussion to the second t-SNARE protein of the SNARE core complex, STX1A, and provide a brief review of the recent paper implicating STX1A in epilepsy and neurodevelopmental disorders.

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Decoding rare disease through 77,000 genomes

Genome sequencing. Despite continual progress in understanding the genetic etiology of human disease, more than half of rare disorders remain unsolved. Resolving the remaining etiologies in rare disease are a major focus of ongoing efforts in the field, including a shift towards standardized analysis of large-scale genome sequencing data from large patient cohorts. In a recent study, Greene and collaborators aimed to identify associations between genes and rare disease subgroups, leveraging genomes of 77,539 people including 29,741 probands. Here is a brief review on their publication in the context of etiological resolution in rare disease.

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The landscape of epilepsy genetics in 2023

Clinical neurogenetics. Characterization of the genetic landscape of the epilepsies continues at a rapid pace, and the effects of this vast gain of knowledge are beginning to show within routine clinical care of people with epilepsy. In our most recent review, we discuss an overview of epilepsy genetics in 2023, spanning topics of novel methods of gene identification, polygenic mechanisms, new presentations of established genes, and multifaceted efforts of phenotypic characterization. In addition, we discuss the increasingly critical roles of advocacy organizations. Here is a summary of our recent review.

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