Compound heterozygous mutations in UBA5 causing early-onset epileptic encephalopathy in two sisters.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesEpileptic encephalopathies are a group of childhood epilepsies that display high phenotypic and genetic heterogeneity. The recent, extensive use of next-generation sequencing has identified a large number of genes in epileptic encephalopathies, including UBA5 in which biallelic mutations were first described as pathogenic in 2016 (Colin E et al., Am J Hum Genet 99(3):695-703, 2016. Muona M et al., Am J Hum Genet 99(3):683-694, 2016). UBA5 encodes an activating enzyme for a post-translational modification mechanism known as ufmylation, and is the first gene from the ufmylation pathway that is linked to disease.We sequenced the genomes of two sisters with early-onset epileptic encephalopathy along with their unaffected parents in an attempt to find a genetic cause for their condition. The sisters, born in 2004 and 2006, presented with infantile spasms at six months of age, which later progressed to recurrent, treatment-resistant seizures. We detected a compound heterozygous genotype in UBA5 in the sisters, a genotype not seen elsewhere in an Icelandic reference set of 30,067 individuals nor in public databases. One of the mutations, c.684G > A, is a paternally inherited exonic splicing mutation, occuring at the last nucleotide of exon 7 of UBA5. The mutation is predicted to disrupt the splice site, resulting in loss-of-function of one allele of UBA5. The second mutation is a maternally inherited missense mutation, p.Ala371Thr, previously reported as pathogenic when in compound heterozygosity with a loss-of-function mutation in UBA5 and is believed to produce a hypomorphic allele. Supportive of this, we have identified three adult Icelanders homozygous for the p.Ala371Thr mutation who show no signs of neurological disease.We describe compound heterozygous mutations in the UBA5 gene in two sisters with early-onset epileptic encephalopathy. To our knowledge, this is the first description of mutations in UBA5 since the initial discovery that pathogenic biallelic variants in the gene cause early-onset epileptic encephalopathy. We further provide confirmatory evidence that p.Ala371Thr is a hypomorphic mutation, by presenting three adult homozygotes who show no signs of neurological disease

The genetic architecture of age-related hearing impairment revealed by genome-wide association analysis.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadAge-related hearing impairment (ARHI) is the most common sensory disorder in older adults. We conducted a genome-wide association meta-analysis of 121,934 ARHI cases and 591,699 controls from Iceland and the UK. We identified 21 novel sequence variants, of which 13 are rare, under either additive or recessive models. Of special interest are a missense variant in LOXHD1 (MAF = 1.96%) and a tandem duplication in FBF1 covering 4 exons (MAF = 0.22%) associating with ARHI (OR = 3.7 for homozygotes, P = 1.7 × 10-22 and OR = 4.2 for heterozygotes, P = 5.7 × 10-27, respectively). We constructed an ARHI genetic risk score (GRS) using common variants and showed that a common variant GRS can identify individuals at risk comparable to carriers of rare high penetrance variants. Furthermore, we found that ARHI and tinnitus share genetic causes. This study sheds a new light on the genetic architecture of ARHI, through several rare variants in both Mendelian deafness genes and genes not previously linked to hearing

The genetic epidemiology of joint shape and the development of osteoarthritis

Congruent, low-friction relative movement between the articulating elements of a synovial joint is an essential pre-requisite for sustained, efficient, function. Where disorders of joint formation or maintenance exist, mechanical overloading and osteoarthritis (OA) follow. The heritable component of OA accounts for ~ 50% of susceptible risk. Although almost 100 genetic risk loci for OA have now been identified, and the epidemiological relationship between joint development, joint shape and osteoarthritis is well established, we still have only a limited understanding of the contribution that genetic variation makes to joint shape and how this modulates OA risk. In this article, a brief overview of synovial joint development and its genetic regulation is followed by a review of current knowledge on the genetic epidemiology of established joint shape disorders and common shape variation. A summary of current genetic epidemiology of OA is also given, together with current evidence on the genetic overlap between shape variation and OA. Finally, the established genetic risk loci for both joint shape and osteoarthritis are discussed

Variant ASGR1 associated with a reduced risk of coronary artery disease

BACKGROUND: Several sequence variants are known to have effects on serum levels of non-high-density lipoprotein (HDL) cholesterol that alter the risk of coronary artery disease. METHODS: We sequenced the genomes of 2636 Icelanders and found variants that we then imputed into the genomes of approximately 398,000 Icelanders. We tested for association between these imputed variants and non-HDL cholesterol levels in 119,146 samples. We then performed replication testing in two populations of European descent. We assessed the effects of an implicated loss-of-function variant on the risk of coronary artery disease in 42,524 case patients and 249,414 controls from five European ancestry populations. An augmented set of genomes was screened for additional loss-of-function variants in a target gene. We evaluated the effect of an implicated variant on protein stability. RESULTS: We found a rare noncoding 12-base-pair (bp) deletion (del12) in intron 4 of ASGR1, which encodes a subunit of the asialoglycoprotein receptor, a lectin that plays a role in the homeostasis of circulating glycoproteins. The del12 mutation activates a cryptic splice site, leading to a frameshift mutation and a premature stop codon that renders a truncated protein prone to degradation. Heterozygous carriers of the mutation (1 in 120 persons in our study population) had a lower level of non-HDL cholesterol than noncarriers, a difference of 15.3 mg per deciliter (0.40 mmol per liter) (P=1.0×10(-16)), and a lower risk of coronary artery disease (by 34%; 95% confidence interval, 21 to 45; P=4.0×10(-6)). In a larger set of sequenced samples from Icelanders, we found another loss-of-function ASGR1 variant (p.W158X, carried by 1 in 1850 persons) that was also associated with lower levels of non-HDL cholesterol (P=1.8×10(-3)). CONCLUSIONS: ASGR1 haploinsufficiency was associated with reduced levels of non-HDL cholesterol and a reduced risk of coronary artery disease. (Funded by the National Institutes of Health and others.)

Physical and cognitive impact following SARS-CoV-2 infection in a large population-based case-control study

© 2023. The Author(s).BACKGROUND: Persistent symptoms are common after SARS-CoV-2 infection but correlation with objective measures is unclear. METHODS: We invited all 3098 adults who tested SARS-CoV-2 positive in Iceland before October 2020 to the deCODE Health Study. We compared multiple symptoms and physical measures between 1706 Icelanders with confirmed prior infection (cases) who participated, and 619 contemporary and 13,779 historical controls. Cases participated in the study 5-18 months after infection. RESULTS: Here we report that 41 of 88 symptoms are associated with prior infection, most significantly disturbed smell and taste, memory disturbance, and dyspnea. Measured objectively, cases had poorer smell and taste results, less grip strength, and poorer memory recall. Differences in grip strength and memory recall were small. No other objective measure associated with prior infection including heart rate, blood pressure, postural orthostatic tachycardia, oxygen saturation, exercise tolerance, hearing, and traditional inflammatory, cardiac, liver, and kidney blood biomarkers. There was no evidence of more anxiety or depression among cases. We estimate the prevalence of long Covid to be 7% at a median of 8 months after infection. CONCLUSIONS: We confirm that diverse symptoms are common months after SARS-CoV-2 infection but find few differences between cases and controls in objective parameters measured. These discrepancies between symptoms and physical measures suggest a more complicated contribution to symptoms related to prior infection than is captured with conventional tests. Traditional clinical assessment is not expected to be particularly informative in relating symptoms to a past SARS-CoV-2 infection.Peer reviewe

Common variants near CAV1 and CAV2 are associated with primary openangle glaucoma.

l e t t e r s We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in 1,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q31 (rs4236601[A], odds ratio (OR) = 1.36, P = 5.0 × 10 −10 ). We then replicated the association in sample sets of 2,175 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = 1.18, P = 0.0015) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.0021). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG. Glaucoma is the leading cause of irreversible blindness worldwide, affecting approximately 70 million people 1 . It is a chronic degenerative optic neuropathy with progressive loss of retinal ganglion cells and axons resulting in a corresponding thinning of the neuroretinal rim of the optic nerve and a characteristic visual field defect. It is distinct from other forms of optic neuropathy in that the neuro retinal rim of the optic nerve retains its normal pink color as it becomes progressively thinner, leading to an enlarged opticnerve cup. POAG is the most common form of glaucoma. Excluding rare primary juvenile glaucoma with age of onset between 10 and 35 years, POAG is arbitrarily divided into highpressure glaucoma (defined as ≥22 mmHg) and normalpressure glaucoma. POAG is thought to have a multifactorial etiology, with the main risk factors being age, elevated intraocular (IOP) pressure, family history, race, central corneal thickness (CCT), hypertension, diabetes and myopia. The familiality of POAG has been known for decades, and studies have revealed three to ninefold greater risk of POAG in firstdegree relatives of POAG cases than in the population in general 2 . Common variants near CAV1 and CAV2 are associated with primary openangle glaucom

18 Eye Clinic

We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in ,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q3 (rs423660[A], odds ratio (OR) = .36, P = 5.0 × 0 −0 ). We then replicated the association in sample sets of 2,75 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = .8, P = 0.005) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.002). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG. Glaucoma is the leading cause of irreversible blindness worldwide, affecting approximately 70 million people 1 . It is a chronic degenerative optic neuropathy with progressive loss of retinal ganglion cells and axons resulting in a corresponding thinning of the neuroretinal rim of the optic nerve and a characteristic visual field defect. It is distinct from other forms of optic neuropathy in that the neuro retinal rim of the optic nerve retains its normal pink color as it becomes progressively thinner, leading to an enlarged opticnerve cup. POAG is the most common form of glaucoma. Excluding rare primary juvenile glaucoma with age of onset between 10 and 35 years, POAG is arbitrarily divided into highpressure glaucoma (defined as ≥22 mmHg) and normalpressure glaucoma. POAG is thought to have a multifactorial etiology, with the main risk factors being age, elevated intraocular (IOP) pressure, family history, race, central corneal thickness (CCT), hypertension, diabetes and myopia. The familiality of POAG has been known for decades, and studies have revealed three to ninefold greater risk of POAG in firstdegree relatives of POAG cases than in the population in general 2 . Common variants near CAV1 and CAV2 are associated with primary openangle glaucom

Lessons learnt from anonymized review of cases of peripartum hysterectomy by international experts: A qualitative pilot study

Severe obstetric complications are not extensively studied and individual cases are used too little and inappropriately in quality improvement activities, due to limited numbers and prioritization of quantitative research. Nordic and European experts performed a qualitative pilot study using anonymized cases of peripartum hysterectomy. It was feasible to anonymize narratives and we learned lessons in the form of themes for improved clinical care and future research. Therefore, we plan a Nordic anonymized review of the care of women who have undergone peripartum hysterectomy based on narratives. The qualitative outcomes of clinically relevant themes for quality improvement and research will add value to the quantitative analyses from the Nordic medical birth registries. In the longer term, we believe that qualitative audits should be essential part of the process of continuing improvement in maternity care. This article is protected by copyright. All rights reserved

Lessons learnt from anonymized review of cases of peripartum hysterectomy by international experts: A qualitative pilot study

Severe obstetric complications are not extensively studied and individual cases are used too little and inappropriately in quality improvement activities, due to limited numbers and prioritization of quantitative research. Nordic and European experts performed a qualitative pilot study using anonymized cases of peripartum hysterectomy. It was feasible to anonymize narratives and we learned lessons in the form of themes for improved clinical care and future research. Therefore, we plan a Nordic anonymized review of the care of women who have undergone peripartum hysterectomy based on narratives. The qualitative outcomes of clinically relevant themes for quality improvement and research will add value to the quantitative analyses from the Nordic medical birth registries. In the longer term, we believe that qualitative audits should be essential part of the process of continuing improvement in maternity care. This article is protected by copyright. All rights reserved