Dr. David Dyment is a clinical investigator at the CHEO Research Institute and Associate Professor at the University of Ottawa. He completed his graduate training in the genetics of complex disease at the University of Oxford and later medical training at the University of Calgary. His clinical interest is neurogenetics with a focus on epilepsy and he works as a clinician in the Neurogenetics program at CHEO.
His current research interests include the identification of genes for human malformation syndromes and also novel genes associated with forms of epilepsy. In addition, he has an active interest in model systems for Dravet syndrome and Spinal Muscular Atrophy and Progressive Myoclonic Epilepsy. He is the recipient of a CIHR Clinical Investigator award and has a University of Ottawa Tier 2 Research Chair in Epilepsy Genetics.
Epilepsy genetics: Current knowledge, applications, and future directions
Drug screening with in vitro and in vivo models of epilepsy can potentially facilitate new treatment strategies.
Biallelic Mutations in BRCA1 Cause a New Fanconi Anemia Subtype
The proband presented at birth with microsomia and dysmorphic features (Fig. 1A). Growth parameters were less than the 0.4 percentile at term (birth weight 1990g, height 40.5 cm, head circumference (HC) 27 cm), and subsequent catch-up growth was not evident at 25 years of age (weight 40 kg, −3.03 S.D.; 135 cm tall, −4.35 S.D.; HC 48.5 cm, approx.−4 to −5 S.D.). Additional congenital abnormalities included sparse hair, upslanted palpebral fissures, blepharophimosis, a narrow palate, dental malocclusion, a high-pitched and hoarse voice, hyper and hypopigmented skin lesions, duodenal stenosis and a slightly enlarged left kidney. She has proximally inserted thumbs (Fig. 1A), 2nd digit camptodactyly, 2–3 toe syndactyly and hyperextensible knees as well as a history of hip dislocation. Conductive hearing loss was diagnosed at 4 years of age. Bone age at 2y 3m was delayed (1y and 6m (−2S.D.)), but had normalized by 9 years. The patient also has mild intellectual disability with significantly delayed speech. At 23 years of age she was diagnosed with ductal breast carcinoma that was estrogen and progesterone receptor positive and Her2 negative. Mastectomy was performed followed by treatment with docetaxel, fluorouracil-epirubicin-cyclophosphamide and radiation therapy. A prophylactic mastectomy was performed on the contralateral breast at age 25. The patient did not experience unusual treatment associated toxicity and has not been diagnosed with bone marrow failure to date.
Resolution of refractory hypotension and anuria in a premature newborn with loss-of-function of ACE
Vasopressin was used to successfully treat refractory hypotension and anuria in the neonate born at 27 weeks of gestation.
Evidence for Clinical, Genetic and Biochemical Variability in Spinal Muscular Atrophy With Progressive Myoclonic Epilepsy
The results of the WES and the functional studies prompted an electromyography (EMG) study that showed evidence of motor neuron disease despite only mild proximal muscle weakness.
Mutations in PIK3R1 Cause SHORT Syndrome
Our findings show that PIK3R1 mutations are the major cause of SHORT syndrome and suggest that the molecular mechanism of disease might involve downregulation of the PI3K-AKT-mTOR pathway.