Identification of a DNA methylation episignature for recurrent constellations of embryonic malformations.

The term "recurrent constellations of embryonic malformations" (RCEM) is used to describe a number of multiple malformation associations that affect three or more body structures. The causes of these disorders are currently unknown, and no diagnostic marker has been identified. Consequently, providing a definitive diagnosis in suspected individuals is challenging.

Evaluation of the diagnostic accuracy of exome sequencing and its impact on diagnostic thinking for patients with rare disease in a publicly funded health care system: A prospective cohort study.

Purpose: To evaluate the diagnostic utility of publicly funded clinical exome sequencing (ES) for patients with suspected rare genetic diseases.

Methods: We prospectively enrolled 297 probands who met eligibility criteria and received ES across 5 sites in Ontario, Canada, and extracted data from medical records and clinician surveys. Using the Fryback and Thornbury Efficacy Framework, we assessed diagnostic accuracy by examining laboratory interpretation of results and assessed diagnostic thinking by examining the clinical interpretation of results and whether clinical-molecular diagnoses would have been achieved via alternative hypothetical molecular tests.

Phenotypic heterogeneity associated with KIF21A: Two new cases and review of the literature.

Our understanding of genetic and phenotypic heterogeneity associated with the clinical spectrum of rare diseases continues to expand. Thorough phenotypic descriptions and model organism functional studies are valuable tools in dissecting the biology of the disease process. Kinesin genes are well known to be associated with specific disease phenotypes and a subset of kinesin genes, including KIF21A, have been associated with more than one disease.

Elucidating the clinical and molecular spectrum of SMARCC2-associated NDD in a cohort of 65 affected individuals.

Purpose: Coffin-Siris and Nicolaides-Baraitser syndromes are recognizable neurodevelopmental disorders caused by germline variants in BAF complex subunits. The SMARCC2 BAFopathy was recently reported. Herein, we present clinical and molecular data on a large cohort.

Bridging clinical care and research in Ontario, Canada: Maximizing diagnoses from reanalysis of clinical exome sequencing data.

We examined the utility of clinical and research processes in the reanalysis of publicly-funded clinical exome sequencing data in Ontario, Canada. In partnership with eight sites, we recruited 287 families with suspected rare genetic diseases tested between 2014 and 2020. Data from seven laboratories was reanalyzed with the referring clinicians.

Homozygous WNT9B variants in two families with bilateral renal agenesis/hypoplasia/dysplasia.

WNT9B plays a key role in the development of the mammalian urogenital system. It is essential for the induction of mesonephric and metanephric tubules, the regulation of renal tubule morphogenesis, and the regulation of renal progenitor cell expansion and differentiation. To our knowledge, WNT9B has not been associated with renal defects in humans; however, WNT9B mice have renal agenesis/hypoplasia and reproductive tract abnormalities.

A pilot eConsultation service in Eastern Ontario: bridging clinical genetics and primary care.

With the rising demand for clinical genetics services, it is a challenge for clinical geneticists to meet the needs of patients and referring primary care providers in a timely way, using current models of genetics health care delivery. One method of providing primary care providers with greater access to clinical genetics expertise is through an electronic consultation (eConsult) service. We describe here a pilot project of a clinical genetics eConsult service that our genetics centre in Eastern Ontario, Canada provided, using the Champlain Building Access to Specialists through eConsultation (BASE) web-based application.

A retrospective review of 48 individuals, including 12 families, molecularly diagnosed with hereditary leiomyomatosis and renal cell cancer (HLRCC).

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is caused by autosomal dominant germline mutations in the fumarate hydratase (FH) gene and is characterized by cutaneous leiomyomas, uterine leiomyomas and aggressive renal malignancies. We conducted a retrospective chart review to characterize the patients referred to our Regional Genetics Program for assessment of HLRCC from 2004 to mid-2016. Forty-eight of 69 (69.

Yunis-Varón syndrome caused by biallelic VAC14 mutations.

Yunis-Varón syndrome (YVS) is an autosomal recessive disorder comprising skeletal anomalies, dysmorphism, global developmental delay and intracytoplasmic vacuolation in brain and other tissues. All hitherto-reported pathogenic variants affect FIG4, a lipid phosphatase involved in phosphatidylinositol (3,5)-bisphosphate [PtdIns(3,5)P] metabolism. FIG4 interacts with PIKfyve, a lipid kinase, via the adapter protein VAC14; all subunits of the resulting complex are essential for PtdIns(3,5)P synthesis in the endolysosomal membrane compartment.

Autosomal dominant cutis laxa with progeroid features due to a novel, de novo mutation in ALDH18A1.

De novo dominant mutations in the aldehyde dehydrogenase 18 family member A1 (ALDH18A1) gene have recently been shown to cause autosomal dominant cutis laxa with progeroid features (MIM 616603). To date, all de novo dominant mutations have been found in a single highly conserved amino acid residue at position p.Arg138.

Preclinical in vivo evaluation of rapamycin in human malignant peripheral nerve sheath explant xenograft.

Neurofibromatosis type 1 (NF1) patients are prone to the development of malignant tumors, the most common being Malignant Peripheral Nerve Sheath Tumor (MPNST). NF1-MPNST patients have an overall poor survival due to systemic metastasis. Currently, the management of MPNSTs includes surgery and radiation; however, conventional chemotherapy is not very effective, underscoring the need for effective biologically-targeted therapies.