Publications by authors named "William Rowell"

While variants cause many Mendelian disorders, their detection currently requires sequencing of the proband and both biological parents. This is not feasible when only one parent is available, a limitation for millions of families. We developed , which identifies variants from single parent-proband duos using long-read sequencing followed by haplotype reconstruction and detection of identical-by-descent haplotype blocks.

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Congenital Adrenal Hyperplasia (CAH), one of the most common inherited disorders, is caused by defects in adrenal steroidogenesis. It is potentially lethal if untreated and is associated with multiple comorbidities, including fertility issues, obesity, insulin resistance, and dyslipidemia. CAH can result from variants in multiple genes, but the most frequent cause is deletions and conversions in the segmentally duplicated RCCX module, which contains the gene and a pseudogene.

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Using five complementary short- and long-read sequencing technologies, we phased and assembled >95% of each diploid human genome in a four-generation, 28-member family (CEPH 1463) allowing us to systematically assess mutations (DNMs) and recombination. From this family, we estimate an average of 192 DNMs per generation, including 75.5 single-nucleotide variants (SNVs), 7.

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Motivation: In diploid organisms, phasing is the problem of assigning the alleles at heterozygous variants to one of two haplotypes. Reads from PacBio HiFi sequencing provide long, accurate observations that can be used as the basis for both calling and phasing variants. HiFi reads also excel at calling larger classes of variation, such as structural or tandem repeat variants.

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Article Synopsis
  • Tandem repeat (TR) variation is linked to gene expression and rare genetic diseases, and there's a demand for better tools to analyze these variations across genomes.
  • The Tandem Repeat Genotyping Tool (TRGT) is introduced as a computational method designed to determine consensus sequences and methylation levels of TRs using PacBio HiFi sequencing data.
  • TRGT demonstrated high accuracy with a 98.38% Mendelian concordance and successfully identified known repeat expansions and their methylation status in samples, while also providing access to a database of TR sequences and methylation levels from 100 genomes.
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  • Despite advances in diagnostics for rare genetic diseases, many patients still lack a molecular diagnosis, indicating a need for new tools and methods for variant detection.
  • Long-read genome sequencing, like PacBio HiFi, offers advantages in identifying complex genomic structures that traditional short-read sequencing might miss, making it valuable for studying rare diseases with genetic links.
  • In a case study of a multi-generational family with 46,XY differences of sexual development, long-read sequencing successfully identified a rare insertion in the NR5A1 gene, demonstrating its potential to uncover impactful genetic variants that standard testing has overlooked.
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Long-read HiFi genome sequencing allows for accurate detection and direct phasing of single nucleotide variants, indels, and structural variants. Recent algorithmic development enables simultaneous detection of CpG methylation for analysis of regulatory element activity directly in HiFi reads. We present a comprehensive haplotype resolved 5-base HiFi genome sequencing dataset from a rare disease cohort of 276 samples in 152 families to identify rare (~0.

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Background: Long-read sequencing (LRS) techniques have been very successful in identifying structural variants (SVs). However, the high error rate of LRS made the detection of small variants (substitutions and short indels < 20 bp) more challenging. The introduction of PacBio HiFi sequencing makes LRS also suited for detecting small variation.

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Genome in a Bottle benchmarks are widely used to help validate clinical sequencing pipelines and develop variant calling and sequencing methods. Here we use accurate linked and long reads to expand benchmarks in 7 samples to include difficult-to-map regions and segmental duplications that are challenging for short reads. These benchmarks add more than 300,000 SNVs and 50,000 insertions or deletions (indels) and include 16% more exonic variants, many in challenging, clinically relevant genes not covered previously, such as .

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  • Scientists developed a new way called DeepConsensus to help correct DNA sequences more accurately than an older method called pbccs.
  • DeepConsensus uses advanced technology to lower errors in the DNA reads by 42%, which means it helps make the sequencing more reliable.
  • This new approach not only improves the quality of the DNA readings but also enhances how genes are understood and reduces mistakes in identifying genetic variations.
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Currently, protein-coding de novo variants and large copy number variants have been identified as important for ~30% of individuals with autism. One approach to identify relevant variation in individuals who lack these types of events is by utilizing newer genomic technologies. In this study, highly accurate PacBio HiFi long-read sequencing was applied to a family with autism, epileptic encephalopathy, cognitive impairment, and mild dysmorphic features (two affected female siblings, unaffected parents, and one unaffected male sibling) with no known clinical variant.

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  • The study focused on improving diagnosis and understanding of genetic disorders in children through the Genomic Answers for Kids program by analyzing genetic information from 960 families.
  • Researchers utilized various sequencing methods, including short-read and long-read genome sequencing, alongside machine learning to prioritize genetic variants and stored the data in a structured database for future access.
  • The results showed varying diagnostic success rates, with new diagnostic information gained from structural variants and long-read sequencing, highlighting ongoing challenges in identifying variants of unknown significance in nondiagnostic cases.
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The repetitive nature and complexity of some medically relevant genes poses a challenge for their accurate analysis in a clinical setting. The Genome in a Bottle Consortium has provided variant benchmark sets, but these exclude nearly 400 medically relevant genes due to their repetitiveness or polymorphic complexity. Here, we characterize 273 of these 395 challenging autosomal genes using a haplotype-resolved whole-genome assembly.

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Similar to many insect species, Drosophila melanogaster is capable of maintaining a stable flight trajectory for periods lasting up to several hours. Because aerodynamic torque is roughly proportional to the fifth power of wing length, even small asymmetries in wing size require the maintenance of subtle bilateral differences in flapping motion to maintain a stable path. Flies can even fly straight after losing half of a wing, a feat they accomplish via very large, sustained kinematic changes to both the damaged and intact wings.

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Objective: We have used long-read single molecule, real-time (SMRT) sequencing to fully characterize a ~12Mb genomic region on chromosome Xq24-q27, significantly linked to bipolar disorder (BD) in an extended family from a genetic sub-isolate. This family segregates BD in at least four generations with 24 affected individuals.

Methods: We selected 16 family members for targeted sequencing.

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The use of pharmacogenomics in clinical practice is becoming standard of care. However, due to the complex genetic makeup of pharmacogenes, not all genetic variation is currently accounted for. Here, we show the utility of long-read sequencing to resolve complex pharmacogenes by analyzing a well-characterised sample.

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Most human genomes are characterized by aligning individual reads to the reference genome, but accurate long reads and linked reads now enable us to construct accurate, phased de novo assemblies. We focus on a medically important, highly variable, 5 million base-pair (bp) region where diploid assembly is particularly useful - the Major Histocompatibility Complex (MHC). Here, we develop a human genome benchmark derived from a diploid assembly for the openly-consented Genome in a Bottle sample HG002.

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Structural variation (SV) is typically defined as variation within the human genome that exceeds 50 base pairs (bp). SV may be copy number neutral or it may involve duplications, deletions, and complex rearrangements. Recent studies have shown SV to be associated with many human diseases.

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The DNA sequencing technologies in use today produce either highly accurate short reads or less-accurate long reads. We report the optimization of circular consensus sequencing (CCS) to improve the accuracy of single-molecule real-time (SMRT) sequencing (PacBio) and generate highly accurate (99.8%) long high-fidelity (HiFi) reads with an average length of 13.

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Dysregulation of alpha-synuclein expression has been implicated in the pathogenesis of synucleinopathies, in particular Parkinson's Disease (PD) and Dementia with Lewy bodies (DLB). Previous studies have shown that the alternatively spliced isoforms of the SNCA gene are differentially expressed in different parts of the brain for PD and DLB patients. Similarly, SNCA isoforms with skipped exons can have a functional impact on the protein domains.

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Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by ∼2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types.

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Spinal injury can result in morbidity and mortality. Research suggests that only a small percentage of patients assessed for spinal fracture have sustained the injury, however, and even fewer have unstable fractures. Protection of the spine and spinal cord is critically important and although many trauma patients leave hospital having had no spinal trauma, despite their mechanism of injury, most arrive with spinal precautions in place.

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Traumatic injuries with haemorrhage are among the leading causes of death in military and civilian settings. Following recent combat in Afghanistan and Iraq, the UK military has made advances in, for example, first-responder haemorrhage control, massive transfusion protocols and equipment, and it is important that staff in ED settings study the results. With reference to a case study concerning a patient who received a fatal stab wound to his femoral artery, this article examines the haemorrhage-control methods adopted by military and civilian emergency medical services to determine if any lessons can be learned and applied to similar cases.

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Infection results in the rapid activation of immunity genes in the Drosophila fat body. Two classes of transcription factors have been implicated in this process: the REL-containing proteins, Dorsal, Dif, and Relish, and the GATA factor Serpent. Here we present evidence that REL-GATA synergy plays a pervasive role in the immune response.

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