Mutations in genes encoding subunits of the phagocyte NADPH oxidase complex are recognized to cause chronic granulomatous disease (CGD), a severe primary immunodeficiency. Here we describe how ...deficiency of CYBC1, a previously uncharacterized protein in humans (C17orf62), leads to reduced expression of NADPH oxidase's main subunit (gp91
) and results in CGD. Analyzing two brothers diagnosed with CGD we identify a homozygous loss-of-function mutation, p.Tyr2Ter, in CYBC1. Imputation of p.Tyr2Ter into 155K chip-genotyped Icelanders reveals six additional homozygotes, all with signs of CGD, manifesting as colitis, rare infections, or a severely impaired PMA-induced neutrophil oxidative burst. Homozygosity for p.Tyr2Ter consequently associates with inflammatory bowel disease (IBD) in Iceland (P = 8.3 × 10
; OR = 67.6), as well as reduced height (P = 3.3 × 10
; -8.5 cm). Overall, we find that CYBC1 deficiency results in CGD characterized by colitis and a distinct profile of infections indicative of macrophage dysfunction.
We performed a genome-wide association study of total hip replacements, based on variants identified through whole-genome sequencing, which included 4,657 Icelandic patients and 207,514 population ...controls. We discovered two rare signals that strongly associate with osteoarthritis total hip replacement: a missense variant, c.1141G>C (p.Asp369His), in the COMP gene (allelic frequency = 0.026%, P = 4.0 × 10
, odds ratio (OR) = 16.7) and a frameshift mutation, rs532464664 (p.Val330Glyfs*106), in the CHADL gene that associates through a recessive mode of inheritance (homozygote frequency = 0.15%, P = 4.5 × 10
, OR = 7.71). On average, c.1141G>C heterozygotes and individuals homozygous for rs532464664 had their hip replacement operation 13.5 years and 4.9 years earlier than others (P = 0.0020 and P = 0.0026), respectively. We show that the full-length CHADL transcript is expressed in cartilage. Furthermore, the premature stop codon introduced by the CHADL frameshift mutation results in nonsense-mediated decay of the mutant transcripts.
Discovery of coding variants in genes that confer risk of neurodevelopmental disorders is an important step towards understanding the pathophysiology of these disorders. Whole-genome sequencing of ...31,463 Icelanders uncovers a frameshift variant (E712KfsTer10) in microtubule-associated protein 1B (MAP1B) that associates with ID/low IQ in a large pedigree (genome-wide corrected P = 0.022). Additional stop-gain variants in MAP1B (E1032Ter and R1664Ter) validate the association with ID and IQ. Carriers have 24% less white matter (WM) volume (β = -2.1SD, P = 5.1 × 10
), 47% less corpus callosum (CC) volume (β = -2.4SD, P = 5.5 × 10
) and lower brain-wide fractional anisotropy (P = 6.7 × 10
). In summary, we show that loss of MAP1B function affects general cognitive ability through a profound, brain-wide WM deficit with likely disordered or compromised axons.
The spread of SARS-CoV-2 is dependent on several factors, both biological and behavioural. The effectiveness of nonpharmaceutical interventions can be attributed largely to changes in human ...behaviour, but quantifying this effect remains challenging. Reconstructing the transmission tree of the third wave of SARS-CoV-2 infections in Iceland using contact tracing and viral sequence data from 2522 cases enables us to directly compare the infectiousness of distinct groups of persons.
The transmission tree enables us to model the effect that a given population prevalence of vaccination would have had on the third wave had one of three different vaccination strategies been implemented before that time. This allows us to compare the effectiveness of the strategies in terms of minimizing the number of cases, deaths, critical cases, and severe cases.
We found that people diagnosed outside of quarantine (Rˆ=1.31) were 89% more infectious than those diagnosed while in quarantine (Rˆ=0.70) and that infectiousness decreased as a function of time spent in quarantine before diagnosis, with people diagnosed outside of quarantine being 144% more infectious than those diagnosed after ≥3 days in quarantine (Rˆ=0.54). People of working age, 16 to 66 years (Rˆ=1.08), were 46% more infectious than those outside of that age range (Rˆ=0.74).
We found that vaccinating the population in order of ascending age or uniformly at random would have prevented more infections per vaccination than vaccinating in order of descending age, without significantly affecting the expected number of deaths, critical cases, or severe cases.
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