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De novo rare EMX2 variants lead to idiopathic hypogonadotropic hypogonadism.

PURPOSE: The genetic etiology of infertility remains unknown. To identify genes for human infertility, we applied a de novo variant analysis in 142 parent-proband trios with idiopathic hypogonadotropic hypogonadism (IHH), an infertility disorder caused by gonadotropin-releasing hormone (GnRH) deficiency. METHODS: Rare de novo copy-number and single-nucleotide variants (CNVs and SNVs) were called from exome sequencing data of the IHH trios. An association study of common EMX2 variants and disease outcomes was performed in the Massachusetts General Brigham Biobank (N = 65,253). GnRH neuronal development and migration was studied in organotypic explants with knocked down of Emx2 and in a mouse model lacking Emx2. RESULTS: We identified that the gene EMX2 harbored both rare de novo CNVs and SNVs. Rare de novo EMX2 variants led to IHH, developmental delay, and hearing loss. Common EMX2 variants were linked to infertility, Parkinson disease, and hearing loss. Knockdown of Emx2 in nasal explants resulted in attenuated GnRH cell migration and GnRH cells were confined to nasal regions of Emx2 knockout (KO) mice, consistent with IHH pathogenesis. CONCLUSION: By utilizing a de novo variant analysis and cellular assays, EMX2 was uncovered as a gene for human infertility.

Humans↗

Genome-wide identification and functional validation of the WW domain containing oxidoreductase gene associated with sleep duration.

Individual differences in sleep duration have been reported, and genetic components of sleep duration have been identified showing various heritability. To identify genetic variants that contribute to sleep duration, we conducted a human genome-wide identification on sleep duration and performed confirmatory experiments using a Drosophila model. Genome-wide association study in human was analyzed to determine the association of the genetic variants with self-aware sleep duration from two community-based cohort, Ansan (cohort 1, n&#x2009;=&#x2009;4635) and Ansung (cohort 2, n&#x2009;=&#x2009;4205), recruited from the Korean Genome and Epidemiology Study. Individual single nucleotide variants (rs16948804 and rs4887991) in the WW domain containing oxidoreductase (WWOX) gene were associated with self-aware sleep duration in human (p-values, 1.11&#x2009;&#xd7;&#x2009;10-&#x2009;7 and 2.05&#x2009;&#xd7;&#x2009;10-&#x2009;7, retrospectively). To examine the functional relevance of the WWOX gene identified in the genome-wide association study, we analyzed the sleep duration of Drosophila loss-of-function mutants. The deletion of Wwox in flies reduced sleep duration and quality with average bout length during daytime and increased night-time sleep duration (all of p-values&#x2009;<&#x2009;0.01). Our findings suggested that WWOX expression is associated with sleep duration in both humans and Drosophila and genetic factors play a role in inter-individual variability in sleep characteristics.

Humans↗

GRN rs5848 variant associates with TDP-43 pathology and cancer in opposite directions.

Epidemiologic studies have reported that cancer survivors have a relatively low risk of developing dementia, but the mechanisms underlying that inverse relationship are mostly unknown. The Granulin (GRN) gene single nucleotide variant rs5848 T allele is associated with increased risk of limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) and hippocampal sclerosis of aging (HS-Aging). The T allele is also associated with lower expression of the cognate protein progranulin (PGRN), which is a mitogen implicated in neoplasia. We examined whether the rs5848 variant associated with LATE-NC/HS-Aging pathology and cancer in the same cohort. This study leveraged genotype data from the Alzheimer's Disease Genomics Consortium (n&#x2009;=&#x2009;8121) and the Alzheimer's Disease Sequencing Project (n&#x2009;=&#x2009;3231), with cancer history and neuropathology data drawn from the National Alzheimer's Coordinating Center. The rs5848 T allele was associated with higher odds of LATE-NC (p&#x2009;<&#x2009;0.001) and was also associated with lower odds of cancer (p&#x2009;=&#x2009;0.012). Established TMEM106B, APOE, and BIN1 risk alleles for Alzheimer's disease showed no associations with cancer, implying that the GRN-related associations could not be completely explained by selection bias in the study sample. The finding of a specific allele with opposite correlative impact on cancer risk and dementia-related pathology has potential therapeutic implications.

Humans↗

Enhanced detection and distinction of RNA by enzymatic probe ligation.

It is important that RNA molecules representing members of gene families are distinguished in expression analyses, and even greater resolving power may be required to identify allelic variants of transcripts in order to investigate imprinting or to study the distribution of mutant genes in tissues. Ligase-mediated gene detection allows precise distinction of DNA sequence variants, but it is not known if ligases can also be used to distinguish variants of RNA sequences. Here we present conditions for efficient ligation of pairs of DNA oligonucleotides hybridizing next to one another on RNA strands, permitting discrimination of any single nucleotide probe-target mismatch by a factor of between 20- and 200-fold. The mechanism allows padlock probes to be used to distinguish single-nucleotide variants in RNA. Ligase-mediated gene detection could therefore provide highly sensitive and accurate ligase-mediated detection and distinction of RNA sequence variants in solution, on DNA microarrays, and in situ.

Alleles↗

Molecular residual disease assessment in colorectal and bladder cancer by somatic structural variant analysis of cell-free DNA whole-genome sequencing data.

BACKGROUND: Whole-genome sequencing (WGS)-based methods for circulating tumor DNA (ctDNA) detection typically rely on tumor-informed identification of somatic single nucleotide variants (SNVs). Somatic structural variants (SVs) are another type of cancer-specific genomic alteration, which owing to their larger genomic footprint and unique breakpoint junctions, are easier to distinguish from sequencing noise than SNVs. They are, however, rarely used for ctDNA detection because of (1) artifacts from WGS procedures that SV callers may falsely interpret as genuine SVs. This makes it difficult to establish high-confidence SV catalogos from short-read tumor WGS and can cause false-positive ctDNA detections. (2) Lack of robust strategies to quantify SV-supporting reads in plasma WGS. To address these barriers and enable integration of SV biomarkers into WGS-based ctDNA detection, we present a bioinformatic framework for algorithmic curation of somatic SV calls from fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tumors, coupled with a novel approach for sensitive, accurate mapping and quantification of SV breakpoint-supporting reads in plasma WGS. METHODS: Tumor, normal and plasma WGS data from 144 patients with stage III colorectal cancer was used to establish the bioinformatic framework. This included ~30x WGS data from 1564 serially collected plasma samples. The framework was validated using tumor/normal/plasma WGS data from 32 patients with muscle-invasive bladder cancer. SV-based ctDNA detection was benchmarked against previously published SNV-based ctDNA results for the same samples. RESULTS: After curation of SV calls and quantification in plasma WGS, our SV-based approach enabled robust ctDNA detection with overall specificity exceeding 99% in plasma samples. Furthermore, we observed strong concordance (Pearson&#x2019;s r&#x2009;>&#x2009;0.93, p&#x2009;<&#x2009;2.2&#x2009;&#xd7;&#x2009;10&#x2212; 16) between ctDNA-positive samples identified by our SV-based method and previous SNV-based analyses, validating the reliability of our approach. Finally, we demonstrated application of the method in an independent bladder cancer cohort, highlighting its generalizability and potential clinical use. CONCLUSIONS: We provide a bioinformatic framework that establishes somatic SVs as ultra-specific biomarkers for WGS-based, tumor-informed ctDNA detection. The approach delivers specific detection even when the SV catalogos are established from FFPE samples. The SV framework can stand alone or enhance SNV-based analysis pipelines.

Humans↗

Molecular genetics of adult-type hypolactasia.

Adult-type hypolactasia (lactase non-persistence; primary lactose malabsorption) is characterized by the down-regulation of the lactase enzyme activity in the intestinal wall after weaning. The down-regulation is genetically determined and a mutation has occurred that has made part of mankind tolerate milk (lactase persistence). A DNA-variant, single nucleotide polymorphism C/T-13910 located 13 910 base pairs (bp) upstream of the lactase gene (LCT) at chromosome 2q21-22 has been shown to associate with the lactase persistence/non-persistence trait both in family and case-control studies. The C/T-13910 variant is located in a non-coding region in the genome in intron 13 of the minichromosome maintenance type 6 gene (MCM6). Significant correlation between the C/T-13910-variant and lactase activity in the intestinal biopsy specimens has been demonstrated. Molecular epidemiological studies on the prevalence of the C/C-13910 genotype associated with low lactase activity are in agreement with the prevalence figures for adult type hypolactasia in>70 diverse ethnic groups studied. Recent functional studies have suggested that this variant has an enhancer effect over the lactase gene. Based on the biochemical, functional, genetic and molecular epidemiological studies of the C/T-13910 variant, genetic testing for adult type hypolactasia has been introduced into clinical practice in Finland. Identification of the genetic change has highlighted the role of non-coding variants in the regulation of common genes and created new tools to study the mechanism of lactase enzyme activation.

Adult↗

Copy number variants in BRCA1 and BRCA2 genes in Polish patients with breast and ovarian cancer.

PURPOSE: BRCA1 and BRCA2 are key susceptibility genes in hereditary breast and ovarian cancer (HBOC), with mutational status guiding PARP inhibitor therapy. While single-nucleotide variants (SNVs) predominate, the prevalence of copy number variants (CNVs) varies significantly across different populations. This study aims to determine the incidence of BRCA1/2 CNVs in the Polish population, where data remain scarce due to non-mandatory CNV testing. METHODS: We retrospectively analysed the results of genetic tests assessing the presence of BRCA1/2 CNVs performed in 2720 individuals tested at the Lower Silesian Oncology Centre (2021-2024), including 2702 breast/ovarian cancer patients and 18 unaffected relatives. The mean age was 54.7&#x2009;&#xb1;&#x2009;15.15&#xa0;years. Genetic testing involved DNA extraction, NGS, and MLPA for CNV confirmation. Variants were classified according to ACMG-AMP guidelines and verified through independent testing. RESULTS: In this study, no BRCA2 CNVs were identified, consistent with previous Central European findings. Pathogenic BRCA1 CNVs were detected in 0.85% of the analyzed cohort and in 0.52% of the cancer patient subgroup, affecting 23 individuals from 13 families. Eight distinct BRCA1 CNVs were detected, the most common being exon 21 deletion. Affected families exhibited a high incidence of HBOC-related cancers, with early-onset breast cancer and a notable proportion of triple-negative breast cancer cases. CONCLUSIONS: This study highlights the clinical significance of BRCA1 CNVs in Polish patients with HBOC-spectrum cancers and their families. Although rare, these variants were associated with aggressive cancer phenotypes and early onset. Given their diagnostic and therapeutic implications, BRCA1 CNVs should be routinely analysed in high-risk families to ensure accurate detection and personalised treatment planning.

Humans↗

Characterization of phosphorylation variants for identifying adaptive alleles in Zea.

Large-scale genome sequencing of maize wild species (teosinte) has uncovered thousands of genetic mutations, but distinguishing causal alleles from neutral variations remains a significant challenge. In this study, we conducted a comprehensive analysis of phosphorylation-associated single-nucleotide variations (pSNVs) to enhance our understanding of adaptive variations in the Zea genus. We collected 234 teosinte genomes from seven different taxa and 507 cultivated maize genomes to identify single-nucleotide variants that target phosphorylation machinery, which is crucial for plant development and environmental adaptation. Our analysis identified 33&#x2009;687 pSNVs within the Zea genus and revealed a reduction in genetic conservation along with an increase in protein abundance and expression for genes harboring pSNVs. Additionally, pSNVs present stronger purifying selection pressures compared with other missense mutations. We found that maize possesses fewer pSNVs than teosinte, likely due to the effects of selection and hitchhiking. By examining the role of pSNVs related to kinase-substrate rewriting events and exhibiting evolutionary divergence jointly, our results suggest that pSNVs impact multiple traits, particularly flowering time variation between teosinte and maize. Furthermore, we documented the widespread presence of pSNVs in Arabidopsis thaliana, rice, and wheat, identifying 46 pSNVs that have convergently evolved between maize and other species. Our study provides another insight into uncovering adaptive alleles in wild species by incorporating protein signaling sites and emphasizes the potential of utilizing wild species for future crop improvement.

Zea mays↗

A detailed Hapmap of the Sitosterolemia locus spanning 69 kb; differences between Caucasians and African-Americans.

BACKGROUND: Sitosterolemia is an autosomal recessive disorder that maps to the sitosterolemia locus, STSL, on human chromosome 2p21. Two genes, ABCG5 and ABCG8, comprise the STSL and mutations in either cause sitosterolemia. ABCG5 and ABCG8 are thought to have evolved by gene duplication event and are arranged in a head-to-head configuration. We report here a detailed characterization of the STSL in Caucasian and African-American cohorts. METHODS: Caucasian and African-American DNA samples were genotypes for polymorphisms at the STSL locus and haplotype structures determined for this locus RESULTS: In the Caucasian population, 13 variant single nucleotide polymorphisms (SNPs) were identified and resulting in 24 different haplotypes, compared to 11 SNPs in African-Americans resulting in 40 haplotypes. Three polymorphisms in ABCG8 were unique to the Caucasian population (E238L, INT10-50 and G575R), whereas one variant (A259V) was unique to the African-American population. Allele frequencies of SNPs varied also between these populations. CONCLUSION: We confirmed that despite their close proximity to each other, significantly more variations are present in ABCG8 compared to ABCG5. Pairwise D' values showed wide ranges of variation, indicating some of the SNPs were in strong linkage disequilibrium (LD) and some were not. LD was more prevalent in Caucasians than in African-Americans, as would be expected. These data will be useful in analyzing the proposed role of STSL in processes ranging from responsiveness to cholesterol-lowering drugs to selective sterol absorption.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

IL-17F sequence variant (His161Arg) is associated with protection against asthma and antagonizes wild-type IL-17F activity.

BACKGROUND: IL-17F is a recently discovered cytokine that plays a role in tissue inflammation by inducing release of proinflammatory and neutrophil-mobilizing cytokines. Upregulated IL17F gene expression has been observed at sites of allergen challenge in the airways of patients with asthma, suggesting that IL-17F is involved in the pathophysiology of asthma. OBJECTIVE: To investigate the role of IL-17F in asthma pathogenesis, we conducted genetic analyses of association of asthma with the common variants of IL17F, using 867 unrelated Japanese subjects. METHODS: Five polymorphisms were studied, including the coding-region sequence variant single nucleotide polymorphism rs763780 (7488T/C), which causes a His-to-Arg substitution at amino acid 161 (H161R). Functional consequences of the H161R substitution were examined by using recombinant wild-type and mutant IL-17F proteins. RESULTS: Homozygosity of the H161R variant was inversely associated with asthma; the odds ratio (95% CI) for asthma was 0.06 (0.01-0.43) for the H161R homozygote compared with the wild-type homozygote (P = .0039). This result remains significant (P = .0079) after adjustment for the presence of atopy using the Mantel-Haenszel chi2 test. In addition, in vitro functional experiments demonstrated that the H161R variant of IL-17F lacks the ability to activate the mitogen-activated protein kinase pathway, cytokine production, and chemokine production in bronchial epithelial cells, unlike wild-type IL-17F. Furthermore, the H161R variant blocked induction of IL-8 expression by wild-type IL-17F. CONCLUSION: The current findings indicate that the IL-17F H161R variant influences the risk of asthma and is a natural IL-17F antagonist, suggesting a potential role for IL-17F in the etiology of asthma.

Adolescent↗

Novel Genetic Loci in Early-Onset Gout Derived From Whole-Genome Sequencing of an Adolescent Gout Cohort.

OBJECTIVE: Mechanisms underlying the adolescent-onset and early-onset gout are unclear. This study aimed to discover variants associated with early-onset gout. METHODS: We conducted whole-genome sequencing in a discovery adolescent-onset gout cohort of 905 individuals (gout onset 12 to 19 years) to discover common and low-frequency single-nucleotide variants (SNVs) associated with gout. Candidate common SNVs were genotyped in an early-onset gout cohort of 2,834 individuals (gout onset &#x2264;30 years old), and meta-analysis was performed with the discovery and replication cohorts to identify loci associated with early-onset gout. Transcriptome and epigenomic analyses, quantitative real-time polymerase chain reaction and RNA sequencing in human peripheral blood leukocytes, and knock-down experiments in human THP-1 macrophage cells investigated the regulation and function of candidate gene RCOR1. RESULTS: In addition to ABCG2, a urate transporter previously linked to pediatric-onset and early-onset gout, we identified two novel loci (Pmeta < 5.0 &#xd7; 10-8): rs12887440 (RCOR1) and rs35213808 (FSTL5-MIR4454). Additionally, we found associations at ABCG2 and SLC22A12 that were driven by low-frequency SNVs. SNVs in RCOR1 were linked to elevated blood leukocyte messenger RNA levels. THP-1 macrophage culture studies revealed the potential of decreased RCOR1 to suppress gouty inflammation. CONCLUSION: This is the first comprehensive genetic characterization of adolescent-onset gout. The identified risk loci of early-onset gout mediate inflammatory responsiveness to crystals that could mediate gouty arthritis. This study will contribute to risk prediction and therapeutic interventions to prevent adolescent-onset gout.

Humans↗

Massively parallel characterization of adolescent idiopathic scoliosis risk variants.

Adolescent idiopathic scoliosis (AIS) is a common pediatric musculoskeletal disorder characterized by lateral spinal curvature, often leading to chronic pain and deformity. Although a significant genetic component to AIS is recognized, the functional impact of most associated genetic variants, particularly those in noncoding regions, remains largely unknown. Using massively parallel reporter assays, we characterize 1664 variant positions in linkage disequilibrium with 26 AIS lead variants identified by genome-wide association studies (GWASs) in chondrocytes, a major cell type implicated in AIS pathogenesis. Using a library of 7173 candidate regulatory sequences, we compare the 1664 reference alleles against 4708 alternate alleles in two human chondrocyte cell lines (TC28a2 and SW1353). Our analysis identifies 92 variants that exhibit significant differential regulatory activity between their reference and alternate alleles, 79 of which are predicted to disrupt transcription factor binding sites, often correlating with their observed regulatory effect. Notably, we validate rs9496392, a single-nucleotide variant near the ADGRG6 locus, which shows consistent differential regulatory activity in both cell lines. ADGRG6 is a key regulator of cartilage homeostasis, and its cartilage-specific knockout in mice results in a scoliosis-like phenotype. The AIS risk allele of rs9496392 (T) is predicted to strongly disrupt several TFBSs, including SP1. This study provides a foundational catalog of functional AIS-associated regulatory variants active in chondrocytes, offering crucial insights into the perturbed gene regulatory networks in AIS. These findings lay the groundwork for identifying biomarkers and potential therapeutic targets for this complex childhood disease.

Journal Article↗

Haplotype analysis of single nucleotide polymorphisms in VEGF gene for vascular dementia.

A case-control study was performed to identify single nucleotide variants of vascular endothelial growth factor (VEGF) gene associated with vascular dementia. Seven SNPs in promoter, 5'-UTR, 3'-UTR, and introns of VEGF gene were identified in 24 Koreans. Three of them, -1154G/A, -7C/T, and 13553C/T, were selected based on allele frequency and linkage disequilibrium (LD), and genotyped in 207 vascular dementia patients and 207 control subjects. Significant association with vascular dementia was not shown (P > 0.05) in the alleles and genotypes of single locus. Subsequent analysis of composing VEGF risk haplotypes associated with vascular dementia was performed with maximum likelihood estimates of their possible haplotypes employing the expectation-maximization (EM) algorithm. Of three-locus haplotypes, only GTC was significantly associated with vascular dementia, conferring a risk of 1.87 (P < 0.05). Of two-locus haplotypes, the risk was observed with the nested forms of the risk haplotype GTC, that is, GT at the loci -1154G/A and -7C/T and TC at the loci -7C/T and 13553C/T (P < 0.05). Our findings suggested some interaction among -1154G/A, -7C/T, and 13553C/T variants in the determination of risk for vascular dementia.

3' Flanking Region↗

Genetic Screening of Colombian Patients With Early-Onset Parkinson Disease.

BACKGROUND AND OBJECTIVES: Early-onset Parkinson disease (EOPD), defined as symptom onset before 50 years of age, accounts for approximately 10% of patients and is suggested to have a greater genetic component than typical late-onset forms of the disease. Recessive variants in PRKN, PINK1, and DJ-1, are the most common genetic cause of EOPD, however, most studies are in patients of white ancestry. This study aims to analyze genetic variants in PRKN, PINK1, and DJ-1 in Colombian patients to help address the gap in EOPD genetic research of South American populations. METHODS: We analyzed 43 unrelated patients with EOPD using Sanger sequencing for the PRKN, PINK1, and DJ-1 genes and employed multiplex ligation-dependent probe amplification to detect copy number variants. Additionally, long-read whole-genome sequencing was conducted on 3 unresolved patients with age at onset before 30 years of age (long-read sequencing [LRS] patient A-C). RESULTS: We identified known pathogenic single-nucleotide variants and copy number variants in the PRKN gene accounting for 2 patients' disease (4.6% of patients). We observed 2 pathogenic variants in PRKN (c.155delA; p.N52Mfs*29 and c.1083+1G>A) in patient 1, who reported an age at onset of 16 years. We further detected a homozygous duplication of PRKN exons 5-6 in an additional patient, age at onset of 18 years. DISCUSSION: Our study helps characterize genetic contributors to EOPD in Colombian patients, demonstrating genetic forms (PRKN, PINK1, and DJ-1) are rare. Our results highlight a need to include diverse populations in research to improve genetic understanding of disease.

Journal Article↗

Unusual Variants in NDUFAF6-Associated Mitochondrial Disease.

A 6-year-old female with global developmental delay, chronic kidney disease (stage III), and renal tubular dysfunction was evaluated in the National Institutes of Health Undiagnosed Diseases Program. Although exome sequencing did not yield a diagnosis, family genome sequencing revealed biallelic variants in NDUFAF6, i.e., a paternally inherited intronic variant (NM_152416.3:c.298-768T>C) and a maternally inherited 1.6 kb deletion (NC_000008.11:g.95044573_95046180del, spanning exon 5). NDUFAF6 plays an important role in mitochondrial complex I assembly by regulating ND1 biogenesis and facilitating the incorporation of NDUFS8. Variants in NDUFAF6 are associated with two OMIM disorders i.e., Fanconi renotubular syndrome 5 (OMIM #618913) and Mitochondrial complex I deficiency, nuclear type 17 (OMIM #618239). The associated phenotypes include proximal tubule dysfunction and degeneration of the central nervous system. The intronic single nucleotide variant in this case (sometimes referred to as the Acadian variant) has been reported to cause aberrant splicing. This case highlights the need to consider comprehensive sequencing methods, such as genome sequencing, to identify atypical variants in planning a comprehensive diagnostic strategy.

Mitochondrial disease↗

Male proband with intractable seizures and a de novo start-codon-disrupting variant in GLUL.

Bi-allelic variants in GLUL, encoding glutamine synthetase and responsible for the conversion of glutamate to glutamine, are associated with a severe recessive disease due to glutamine deficiency. A dominant disease mechanism was recently reported in nine females, all with a de novo single-nucleotide variant within the start codon or the 5' UTR of GLUL that truncates 17 amino acids of the protein product, including its critical N-terminal degron sequence. This truncation results in a disorder of abnormal glutamine synthetase stability and manifests as a phenotype of severe developmental and epileptic encephalopathy. Here, we report the first male with a pathogenic de novo variant in the same critical region of GLUL, with a phenotype of refractory focal and generalized seizures, as well as developmental delays. We provide a detailed description of the disease course and treatment response.

Humans↗

Hypoadiponectinemia is associated with progression toward type 2 diabetes and genetic variation in the ADIPOQ gene promoter.

OBJECTIVE: Adiponectin encoded by the ADIPOQ gene modulates insulin sensitivity and glucose homeostasis. The aim of the current study was to investigate whether ADIPOQ gene variants in the promoter region predict adiponectin levels and type 2 diabetes progression. RESEARCH DESIGN AND METHODS: A total of 550 subjects with increased risk of type 2 diabetes were investigated; they underwent a 75-g oral glucose tolerance test, repeated after 3 years. Adiponectin levels were analyzed, and two ADIPOQ promoter variant single nucleotide polymorphisms, -11391G>A and -11377C>G, were genotyped. RESULTS: Tertiles of the adjusted adiponectin levels were associated with single nucleotide polymorphism -11391G>A and -11377C>G haplotypes (P < 0.0001). Carriers of the intermediate/high-level haplotype combination showed a bisected diabetes risk at the 3-year follow-up and were characterized by a "regression" of glucose tolerance. Evolution of disease status correlates with preexisting low adiponectin levels at inclusion rather than with variation in adiponectin levels. CONCLUSIONS: We present data that gene variants in the ADIPOQ promoter region are associated with variations in adiponectin levels and thus with future type 2 diabetes and disease progression.

Adiponectin↗

Utility of genome sequencing and group-enrichment to support splice variant interpretation in Marfan syndrome.

PURPOSE: To quantify the impact of noncanonical FBN1 splice site variants in undiagnosed Marfan syndrome (MFS), a connective tissue disorder associated with skeletal abnormalities and familial thoracic aortic aneurysm disease (FTAAD). METHODS: A systematic analysis of ultrarare FBN1 variants was performed using genome sequencing data from the 100,000 Genomes Project. Variants were annotated with SpliceAI and the significance of enrichment among individuals with FTAAD was assessed using Fisher's exact test. Experimental validation used RNA sequencing, reverse transcriptase polymerase chain reaction, minigene constructs, and replication analysis was with data from UK Biobank. RESULTS: Using aggregate data for 78,195 individuals, we identified 13,864 singleton single-nucleotide variants in FBN1 of which 21 were predicted to affect splicing (SpliceAI > 0.5). Incidence of candidate splice variants in individuals recruited with FTAAD (9/703) was significantly elevated compared with that seen in non-FTAAD participants (12/77,492; odds ratio = 84, P = 9.7 &#xd7; 10-14). Additional analysis uncovered a further 14 families harboring 11 different FBN1 splice variants. A total of 20 candidate splice variants in 23 families were identified, of which 70% lay beyond the &#xb1;8 splice regions. RNA testing confirmed the predicted splice aberration in 16 of 20 and for 9 of 20, pseudoexonization was the likely splicing anomaly. CONCLUSION: Our findings indicate that noncanonical splice variants may account for approximately 3% of families with undiagnosed FTAAD, highlighting the importance of incorporating analysis of introns and confirmatory RNA testing into genetic testing for Marfan syndrome.

Humans↗