👤 Shana McCormack

Health-related fitness (HRF) is essential for wellbeing and daily functioning. While objective fitness assessments are preferred, self-report measures are practical for large-scale or geographically diverse studies. Existing self-report HRF measures may lack sensitivity for younger or healthy adults. Additionally, many include items with no or poorly defined reference populations, potentially limiting their validity and comparability. This study examined the reliability and validity of single-item self-reported HRF measures of aerobic fitness, muscular strength and endurance, flexibility, coordination, agility, and body composition. Between April and July 2023, University of Calgary students and staff (N.=129; mean age 28±9 years) completed the first questionnaire, with subsets completing a second questionnaire and validated fitness assessment. Nine items captured participants' self-rated HRF relative to those of the same age and gender. The nine self-reported HRF items were aggregated to obtain an estimate of overall HRF (Multidimensional Health-Related Fitness Scale, MHFS). We used intraclass correlations (ICC) to estimate test-retest reliability of the individual self-reported HRF items and MHFS. We assessed convergent validity with self-reported leisure physical activity (LPA) and concurrent validity with objective fitness measures using age- and sex-adjusted partial correlations. The single-item self-reported HRF measures (ICC=0.60-0.85) and MHFS (ICC=0.87) had acceptable test-retest reliability. The MHFS also had high internal consistency (Cronbach's α=0.87). Evidence of validity was observed with partial correlations ≥0.30 between self-reported HRF and LPA, and objective fitness measures. The MHFS provides a reliable and valid HRF indicator among younger adult populations. Show less

Pituitary tumours are relatively common, and familial in approximately 5% of cases. However, germline genetic contributions to pituitary tumour development are incompletely characterised. Preliminary evidence suggests pituitary tumours may be promoted by variants in pituitary organogenesis genes. Our study aimed to identify rare germline variants in pituitary organogenesis genes that may contribute to pituitary tumour development. A familial case of pituitary disease was investigated. We also examined 36 pituitary organogenesis genes in 134 individuals with pituitary tumours using a targeted next-generation sequencing panel, identifying and characterising variants with a population allele frequency < 0.05%. One patient with a prolactin-secreting pituitary tumour and his daughter with combined pituitary hormone deficiency shared a rare germline variant in FGFR1, c.386 A > C, p.(D129A). In our broader study, we identified an additional individual with the FGFR1 D129A variant and demonstrated enrichment compared to a control population derived from the Genome Aggregation Database (gnomAD). We also observed 66 rare germline variants in pituitary organogenesis genes amongst 54/134 individuals (40%). However, compared to control data, the study cohort exhibited no enrichment for other rare variants in FGFR1, FGF-related genes, or other pituitary embryogenesis genes. Our results suggest that the FGFR1 D129A variant may be associated with pituitary tumorigenesis but the role of other pituitary embryogenesis genes remains unclear. Additional independent cohorts and functional studies are required. Show less

Sneddon-Wilkinson (SW) disease is rare condition which typically occurs in the context of a monoclonal immunoglobulin and treatment options have not been well studied. Here we present a case of a 65-year-old female with SW with underlying, otherwise indolent, lymphoplasmacytic lymphoma (LPL) with an IgA paraprotein, who achieved a complete skin remission with the administration of the Bruton Tyrosine Kinase inhibitor (BTKi), acalabrutinib. Show less

Biallelic variants in IL6ST, encoding GP130, cause a recessive form of hyper-IgE syndrome (HIES) characterized by high IgE level, eosinophilia, defective acute phase response, susceptibility to bacterial infections, and skeletal abnormalities due to cytokine-selective loss of function in GP130, with defective IL-6 and IL-11 and variable oncostatin M (OSM) and IL-27 levels but sparing leukemia inhibitory factor (LIF) signaling. Our aim was to understand the functional and structural impact of recessive HIES-associated IL6ST variants. We investigated a patient with HIES by using exome, genome, and RNA sequencing. Functional assays assessed IL-6, IL-11, IL-27, OSM, LIF, CT-1, CLC, and CNTF signaling. Molecular dynamics simulations and structural modeling of GP130 cytokine receptor complexes were performed. We identified a patient with compound heterozygous novel missense variants in IL6ST (p.Ala517Pro and the exon-skipping null variant p.Gly484_Pro518delinsArg). The p.Ala517Pro variant resulted in a more profound IL-6- and IL-11-dominated signaling defect than did the previously identified recessive HIES IL6ST variants p.Asn404Tyr and p.Pro498Leu. Molecular dynamics simulations suggested that the p.Ala517Pro and p.Asn404Tyr variants result in increased flexibility of the extracellular membrane-proximal domains of GP130. We propose a structural model that explains the cytokine selectivity of pathogenic IL6ST variants that result in recessive HIES. The variants destabilized the conformation of the hexameric cytokine receptor complexes, whereas the trimeric LIF-GP130-LIFR complex remained stable through an additional membrane-proximal interaction. Deletion of this membrane-proximal interaction site in GP130 consequently caused additional defective LIF signaling and Stüve-Wiedemann syndrome. Our data provide a structural basis to understand clinical phenotypes in patients with IL6ST variants. Show less

Modulators of epithelial-to-mesenchymal transition (EMT) have recently emerged as novel players in the field of leukemia biology. The mechanisms by which EMT modulators contribute to leukemia pathogenesis, however, remain to be elucidated. Here we show that overexpression of SNAI1, a key modulator of EMT, is a pathologically relevant event in human acute myeloid leukemia (AML) that contributes to impaired differentiation, enhanced self-renewal, and proliferation of immature myeloid cells. We demonstrate that ectopic expression of Snai1 in hematopoietic cells predisposes mice to AML development. This effect is mediated by interaction with the histone demethylase KDM1A/LSD1. Our data shed new light on the role of SNAI1 in leukemia development and identify a novel mechanism of LSD1 corruption in cancer. This is particularly pertinent given the current interest surrounding the use of LSD1 inhibitors in the treatment of multiple different malignancies, including AML. Show less

Although hundreds of genome-wide association studies-implicated loci have been reported for adult obesity-related traits, less is known about the genetics specific for early-onset obesity and with only a few studies conducted in non-European populations to date. Searching for additional genetic variants associated with childhood obesity, we performed a trans-ancestral meta-analysis of 30 studies consisting of up to 13 005 cases (≥95th percentile of body mass index (BMI) achieved 2-18 years old) and 15 599 controls (consistently <50th percentile of BMI) of European, African, North/South American and East Asian ancestry. Suggestive loci were taken forward for replication in a sample of 1888 cases and 4689 controls from seven cohorts of European and North/South American ancestry. In addition to observing 18 previously implicated BMI or obesity loci, for both early and late onset, we uncovered one completely novel locus in this trans-ancestral analysis (nearest gene, METTL15). The variant was nominally associated with only the European subgroup analysis but had a consistent direction of effect in other ethnicities. We then utilized trans-ancestral Bayesian analysis to narrow down the location of the probable causal variant at each genome-wide significant signal. Of all the fine-mapped loci, we were able to narrow down the causative variant at four known loci to fewer than 10 single nucleotide polymorphisms (SNPs) (FAIM2, GNPDA2, MC4R and SEC16B loci). In conclusion, an ethnically diverse setting has enabled us to both identify an additional pediatric obesity locus and further fine-map existing loci. Show less

Mutations in melanocortin receptor (MC4R) are the most common cause of monogenic obesity in children of European ancestry, but little is known about their prevalence in children from the minority populations in the United States. This study aims to identify the prevalence of MC4R mutations in children with severe early-onset obesity of African American or Latino ancestry. Participants were recruited from the weight management clinics at two hospitals and from the institutional biobank at a third hospital. Sequencing of the MC4R gene was performed by whole exome or Sanger sequencing. Functional testing was performed to establish the surface expression of the receptor and cAMP response to its cognate ligand α-melanocyte-stimulating hormone. Three hundred twelve children (1 to 18 years old, 50% girls) with body mass index (BMI) >120% of 95th percentile of Centers for Disease Control and Prevention 2000 growth charts at an age <6 years, with no known pathological cause of obesity, were enrolled. Eight rare MC4R mutations (2.6%) were identified in this study [R7S, F202L (n = 2), M215I, G252D, V253I, I269N, and F284I], three of which were not previously reported (G252D, F284I, and R7S). The pathogenicity of selected variants was confirmed by prior literature reports or functional testing. There was no significant difference in the BMI or height trajectories of children with or without MC4R mutations in this cohort. Although the prevalence of MC4R mutations in this cohort was similar to that reported for obese children of European ancestry, some of the variants were novel. Show less

A large number of genetic loci are associated with adult body mass index. However, the genetics of childhood body mass index are largely unknown. We performed a meta-analysis of genome-wide association studies of childhood body mass index, using sex- and age-adjusted standard deviation scores. We included 35 668 children from 20 studies in the discovery phase and 11 873 children from 13 studies in the replication phase. In total, 15 loci reached genome-wide significance (P-value < 5 × 10(-8)) in the joint discovery and replication analysis, of which 12 are previously identified loci in or close to ADCY3, GNPDA2, TMEM18, SEC16B, FAIM2, FTO, TFAP2B, TNNI3K, MC4R, GPR61, LMX1B and OLFM4 associated with adult body mass index or childhood obesity. We identified three novel loci: rs13253111 near ELP3, rs8092503 near RAB27B and rs13387838 near ADAM23. Per additional risk allele, body mass index increased 0.04 Standard Deviation Score (SDS) [Standard Error (SE) 0.007], 0.05 SDS (SE 0.008) and 0.14 SDS (SE 0.025), for rs13253111, rs8092503 and rs13387838, respectively. A genetic risk score combining all 15 SNPs showed that each additional average risk allele was associated with a 0.073 SDS (SE 0.011, P-value = 3.12 × 10(-10)) increase in childhood body mass index in a population of 1955 children. This risk score explained 2% of the variance in childhood body mass index. This study highlights the shared genetic background between childhood and adult body mass index and adds three novel loci. These loci likely represent age-related differences in strength of the associations with body mass index. Show less