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Menzies, L.

Publications and source records attributed to Menzies, L..

2 recordsLinked to original sources

High-throughput behavioural phenotyping of 25 C. elegans disease models including patient-specific mutations

Genetic diagnosis is fast and cheap, challenging our capacity to evaluate the functional impact of novel disease-causing variants or identify potential therapeutics. Model organisms including C. elegans present the possibility of systematically modelling genetic diseases, yet robust, high-throughput methods have been lacking. Here we show that automated multi-dimensional behaviour tracking can detect phenotypes in 25 new C. elegans disease models spanning homozygous loss-of-function alleles and patient-specific single-amino-acid substitutions. We find that homozygous loss-of-function (LoF) mutants across diverse genetic pathways (including BORC, FLCN, and FNIP-2) exhibit strong, readily detectable abnormalities in posture, locomotion, and stimulus responses compared to wild-type animals. An smc-3 mutant strain--modelled by introducing a patient-identified missense change--causes developmental anomalies and distinct behavioural profiles even though complete loss of SMC-3 is lethal. In contrast, patient-derived missense mutations in another essential gene, tnpo-2, did not show a strong phenotype initially but it could be "sensitized" chemically (e.g., with aldicarb), potentially facilitating future drug screens. Our findings show that scalable behavioural phenotyping can capture a wide range of mutant effects--from strong to subtle--in patient-avatar worm lines. We anticipate that this standardized approach will enable systematic drug repurposing for rare genetic disorders as new disease variants are discovered.

animal behavior and cognition↗

Whole genome sequencing for diagnosis of neurological repeat expansion disorders

BackgroundRepeat expansion (RE) disorders affect ~1 in 3000 individuals and are clinically heterogeneous diseases caused by expansions of short tandem DNA repeats. Genetic testing is often locus-specific, resulting in under diagnosis of atypical clinical presentations, especially in paediatric patients without a prior positive family history. Whole genome sequencing (WGS) is emerging as a first-line test for rare genetic disorders, but until recently REs were thought to be undetectable by this approach. MethodsWGS pipelines for RE disorder detection were deployed by the 100,000 Genomes Project and Illumina Clinical Services Laboratory. Performance was retrospectively assessed across the 13 most common neurological RE loci using 793 samples with prior orthogonal testing (182 with expanded alleles and 611 with alleles within normal size) and prospectively interrogated in 13,331 patients with suspected genetic neurological disorders. FindingsWGS RE detection showed minimum 97{middle dot}3% sensitivity and 99{middle dot}6% specificity across all 13 disease-associated loci. Applying the pipeline to patients from the 100,000 Genomes Project identified pathogenic repeat expansions which were confirmed in 69 patients, including seven paediatric patients with no reported family history of RE disorders, with a 0.09% false positive rate. InterpretationWe show here for the first time that WGS enables the detection of causative repeat expansions with high sensitivity and specificity, and that it can be used to resolve previously undiagnosed neurological disorders. This includes children with no prior suspicion of a RE disorder. These findings are leading to diagnostic implementation of this analytical pipeline in the NHS Genomic Medicine Centres in England. FundingMedical Research Council, Department of Health and Social Care, National Health Service England, National Institute for Health Research, Illumina Inc

genomics↗