Dr Richard Caswell
Associate Research Fellow (Named Researcher)
I have worked as a member of the Monogenic Diabetes group since June 2009, using high-throughput (‘Next Generation’) sequencing techniques for the discovery of novel causative genes and mutations in neonatal diabetes, hyperinsulinism and other diseases of pancreatic dysfunction. This work has been carried out in close association with the Department of Molecular Genetics at the Royal Devon and Exeter NHS Foundation Trust, and having initially implemented these techniques for research studies, we have now been able to transfer these into the diagnostic setting, offering rapid, high-throughput testing not only for monogenic diabetes but for a wide range of inherited diseases. As well as continuing this work, I am also developing high sensitivity methods for the non-invasive detection of specific diabetes mutations in pregnant mothers, which will help inform clinical care during and after pregnancy and reduce the risk of complications such as macrosomia (see 'Research'). This work will bring together molecular genetic techniques with cutting-edge detection methods to allow delivery of truly personalized healthcare.
Prior to moving to Exeter, my experience as a protein biochemist gave me opportunities to collaborate with the Monogenic Diabetes and Molecular Genetics groups on interpreting the effects of novel missense variants. This work has continued throughout my time in Exeter, and involves the analysis of protein sequence and structure using freely-available bioinformatics tools, to try to gain insights into the effect of mutations on protein function. Since such effects are highly context-specific, this usually requires interpretation of potential molecular defects on a case-by-case basis, and this represents a challenge in the era of high-throughput sequencing and variant discovery.
PhD (University of Wales, 1988)
BSc (Hons) (University of Wales, 1985)
- 1997-2007: Lecturer, School of Biosciences, Cardiff University
- 1991-1997: Research Associate, School of Medicine, University of Cambridge
- 1988-1991: Research Fellow, Schools of Biochemistry and Chemical Engineering, University of Birmingham
Selected recent publications
Elouej S, Beleza-Meireles A, Caswell R, Colclough K et al. (2017). Exome sequencing reveals a de novo POLD1 mutation causing phenotypic variability in mandibular hypoplasia, deafness, progeroid features, and lipodystrophy syndrome (MDPL). Metabolism 71:213-225. PMID: 28521875.
Flanagan SE, Vairo F, Johnson MB, Caswell R, Laver TW, Lango Allen H, Hussain K & Ellard S (2017). A CACNA1D mutation in a patient with persistent hyperinsulinaemic hypoglycaemia, heart defects, and severe hypotonia. Pediatr Diabetes. 18:320-323. PMID: 28318089
Cabezas OR, Flanagan SE, Stanescu H, García-Martínez E, Caswell R et al. (2017). Polycystic Kidney Disease with Hyperinsulinemic Hypoglycemia Caused by a Promoter Mutation in Phosphomannomutase 2. J Am Soc Nephrol. doi:10.1681/ASN.2016121312. [Epub ahead of print] PMID: 28373276.
De Franco E, Caswell R, Houghton JA, Iotova V, Hattersley AT & Ellard S (2017). Analysis of cell-free fetal DNA for non-invasive prenatal diagnosis in a family with neonatal diabetes. Diabet Med. 34:582-585. PMID: 27477181.
Iacovazzo D, Caswell R, Bunce B, Jose S et al. (2016). Germline or somatic GPR101 duplication leads to X-linked acrogigantism: a clinico-pathological and genetic study. Acta Neuropathol Commun. 4:56. PMID: 27245663.
Laver TW, Caswell RC, Moore KA, Poschmann J, Johnson MB, Owens MM, Ellard S, Paszkiewicz KH & Weedon MN (2016). Pitfalls of haplotype phasing from amplicon-based long-read sequencing. Scientific Reports 6:21746. PMID: 26883533.
Sansbury FH, Kirel B, Caswell R, Allen Lango H, Flanagan SE, Hattersley AT, Ellard S, Shaw-Smith CJ (2015). Biallelic RFX6 mutations can cause childhood as well as neonatal onset diabetes mellitus. European Journal of Human Genetics 23:1744-1748. PMID: 26264437.
Ellard S, Kivuva E, Turnpenny P, Stals K, Johnson M, Xie W, Caswell R & Lango Allen H (2015). An exome sequencing strategy to diagnose lethal autosomal recessive disorders. European Journal of Human Genetics 23:401-404. PMID: 24961629.
Flanagan SE, Haapaniemi E, Russell MA, Caswell R, Lango Allen H et al. (2014). Activating germline mutations in STAT3 cause early-onset multi-organ autoimmune disease. Nature Genetics 46:812-814. PMID: 25038750.
Hartill VL, Tysoe C, Manning N, Dobbie A, Santra S, Walter J, Caswell R, Koster J, Waterham H & Hobson E (2014). An unusual phenotype of X-linked developmental delay and extreme behavioral difficulties associated with a mutation in the EBP gene. American Journal of Medical Genetics A 164A:907-914. PMID: 24459067.
Lango Allen H, Caswell R, Xie W, Xu X, Wragg C, Turnpenny PD, Turner CLS, Weedon MN & Ellard S (2014). Next generation sequencing of chromosomal rearrangements in patients with split-hand/split-foot malformation provides evidence for DYNC1I1 exonic enhancers of DLX5/6 expression in humans. Journal of Medical Genetics 51:264-267. PMID: 24459211.
Ellard S, Lango Allen H, De Franco E, Flanagan SE, Hysenaj G, Colclough K, Houghton JAL, Shepherd M, Hattersley AT, Weedon MN & Caswell R (2013). Improved genetic testing for monogenic diabetes using targeted next-generation sequencing. Diabetologia 56:1958-1963. PMID: 23771172.
Weedon MN, Cebola I, Patch AM, Flanagan SE, De Franco E, Caswell R et al. (2014). Recessive mutations in a distal PTF1A enhancer cause isolated pancreatic agenesis. Nature Genetics 46:61-64. PMID: 24212882.
Weedon MN, Ellard S, Prindle MJ, Caswell R, Lango Allen H et al. (2013). An in-frame deletion at the polymerase active site of POLD1 causes a multisystem disorder with lipodystrophy. Nature Genetics 45:947-950. PMID: 23770608
Flanagan SE, Xie W, Caswell R, Damhuis A, Vianey-Saban C et al. (2013). Next-generation sequencing reveals deep intronic cryptic ABCC8 and HADH splicing founder mutations causing hyperinsulinism by pseudoexon activation. American Journal of Human Genetics 92:131-136. PMID: 23273570.
Lango Allen H, Flanagan SE, Shaw-Smith S, De Franco E, Akerman I, Caswell R, International Pancreatic Agenesis Consortium, Ferrer J, Hattersley AT & Ellard S (2011). GATA6 haploinsufficiency causes pancreatic agenesis in humans. Nature Genetics 44:20-22. PMID: 22158542.
Weedon MN, Hastings R, Caswell R, Xie W, Paszkiewicz K, Antoniadi T, Williams M, King C, Greenhalgh L, Newbury-Ecob R & Ellard S (2011). Exome sequencing identifies a DYNC1H1 mutation in a large pedigree with dominant axonal Charcot-Marie-Tooth Disease. American Journal of Human Genetics 89:308-312. PMID: 21820100.
Dr Caswell explains his research into non-invasive foetal DNA testing to predict pregnancies at risk of macrosomia in the video below, filmed at the Living Systems Institute Research Symposium in March 2016.