ANXA11 Gene Research Articles

Clinical and genetic characteristics of amyotrophic lateral sclerosis patients with ANXA11 variants.

Increasing genetic evidence supports the hypothesis that variants in the annexin A11 gene (ANXA11) contribute to amyotrophic lateral sclerosis pathogenesis. Therefore, we studied the clinical aspects of sporadic amyotrophic lateral sclerosis patients carrying ANXA11 variants. We also implemented functional experiments to verify the pathogenicity of the hotspot variants associated with amyotrophic lateral sclerosis-frontotemporal dementia. Korean patients diagnosed with amyotrophic lateral sclerosis (n = 882) underwent genetic evaluations through next-generation sequencing, which identified 16 ANXA11 variants in 26 patients. We analysed their clinical features, such as the age of onset, progression rate, initial symptoms and cognitive status. To evaluate the functional significance of the ANXA11 variants in amyotrophic lateral sclerosis-frontotemporal dementia pathology, we additionally utilized patient fibroblasts carrying frontotemporal dementia-linked ANXA11 variants (p.P36R and p.D40G) to perform a series of in vitro studies, including calcium imaging, stress granule dynamics and protein translation. The frequency of the pathogenic or likely pathogenic variants of ANXA11 was 0.3% and the frequency of variants classified as variants of unknown significance was 2.6%. The patients with variants in the low-complexity domain presented unique clinical features, including late-onset, a high prevalence of amyotrophic lateral sclerosis-frontotemporal dementia, a fast initial progression rate and a high tendency for bulbar-onset compared with patients carrying variants in the C-terminal repeated annexin homology domains. In addition, functional studies using amyotrophic lateral sclerosis-frontotemporal dementia patient fibroblasts revealed that the ANXA11 variants p.P36R and p.D40G impaired intracellular calcium homeostasis, stress granule disassembly and protein translation. This study suggests that the clinical manifestations of amyotrophic lateral sclerosis and amyotrophic lateral sclerosis-frontotemporal dementia spectrum patients with ANXA11 variants could be distinctively characterized depending upon the location of the variant.

Genetic analysis of and clinical characteristics associated with ANXA11 variants in a Chinese cohort with amyotrophic lateral sclerosis

BackgroundVariants in the annexin A11 gene (ANXA11) have been reported to be associated with amyotrophic lateral sclerosis (ALS). These variants may be involved in the pathogenesis of ALS by causing defects in intracellular protein trafficking. However, the genetic spectrum and clinical characteristics of ALS patients with ANXA11 variants are largely unknown. MethodsGenetic analysis was performed on 1587 Chinese patients with ALS. Eight software packages were used to predict the deleteriousness of missense variants. In addition, we searched PubMed, Embase, and Web of Science for relevant literature and meta-analysed variant frequencies. ResultsIn our ALS cohort, we identified 20 non-synonymous variants in 29 ALS patients, including one stop-gain, one frameshift, and 18 rare missense variants with seven predicted pathogenic variants. In a literature review of 11 reported studies that included 69 patients, 37 ANXA11 variants were reported, with a frequency of 1.7%, which was similar to that in our cohort (1.8%). Both our cohort and previous reports showed that ANXA11 carriers were more commonly males than females (12/17 vs. 19/31). Patients carrying ANXA11 variants affecting the C-terminal of the protein had earlier disease onset and shorter survival times than those carrying variants affecting the N-terminal. We found a relatively longer median survival time than that previously reported (53.6 months vs. 46.0 months). Additionally, Caucasian ANXA11 carriers were more likely to have cognitive impairment, typically frontotemporal dementia (FTD) than their Asian counterparts (20.0% vs. 14.3%). While more than half of the patients in our cohort had cognitive impairment, none had FTD. ConclusionIn our and previously published cases, ALS-associated ANXA11 variants predominantly affected the N- and C-terminal conserved domains. ANXA11 variant carriers are typically male and cognitively impaired. Our study extends the genotypic and phenotypic spectra of ALS patients with ANXA11 variants. Further expansion of the sample size is needed to analyse the clinical and non-motor symptom characteristics of patients and to deepen the understanding of the pathogenesis of ANXA11-associated ALS.

ANXA11 rs1049550 Associates with Löfgren's Syndrome and Chronic Sarcoidosis Patients.

Sarcoidosis is an immune mediated granulomatous disease commonly affecting the lungs. Genome wide association studies identified many genomic regions that are shared among multiple immune mediated diseases. However, ANXA11 gene polymorphism rs1049550 is exclusively associated with sarcoidosis, making it a key gene of interest for sarcoidosis disease pathogenesis. However, sarcoidosis is a heterogeneous disease and contradictory findings for ANXA11 have been reported for disease phenotypes. We performed a case–control association study to investigate if ANXA11 associates with benign (Löfgren’s syndrome (LS)) or chronic sarcoidosis and performed a meta-analysis on previously reported findings. A total of 262 sarcoidosis patients, of which 149 had LS and 113 chronic sarcoidosis, and 363 controls were genotyped for rs1049550. Meta-analysis included allele findings for rs1049550 from 6 additional studies. We found a significantly lower T allele frequency in sarcoidosis patients than in healthy controls (0.30 vs. 0.41, respectively, odds ratio (OR) 0.61, 95% confidence interval (CI) 0.48–0.77, p = 3 × 10−5). In LS the T allele frequency of 0.33, and in chronic sarcoidosis the T allele frequency of 0.26 were significantly lower than in healthy controls (OR 0.69, 95% CI 0.52–0.92, p = 0.01 and OR 0.51, 95% CI 0.36–0.70, p = 4 × 10−5, respectively). Meta-analysis including previously published European, African American and Asian cohorts confirmed the association of rs1049550 with sarcoidosis and resulted in a pooled OR of 0.70 (CI 0.66–0.75, p = 3.58 × 10−29). Presence of the T allele of rs1049550 in ANXA11 is protective for sarcoidosis, including benign and chronic phenotypes of the disease.

Two rare variants of the ANXA11 gene identified in Chinese patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. A recent study has identified mutations in the ANXA11 gene (encoding the calcium-binding protein annexin A11) associated with ALS. Mutation screening of ANXA11 protein-coding exons was performed in a Chinese cohort of 434 patients with sporadic ALS and 50 index patients with familial ALS. Polymerase chain reaction and Sanger sequencing were used for mutation detection. We failed to discover an N-terminal mutation, which was common in the Caucasian cohort. We revealed two rare heterozygous missense variants, c.878C>T (p.A293V) and c.921C>G (p.I307M), which are absent from the population databases and non-neurological controls. They are both located in the conserved annexin domain. The carriers of the mutation exhibited the classical ALS phenotype without cognitive impairment. Our results suggested that further functional studies for these variants are required to support the pathogenicity.

Genetic analysis of ANXA11 variants in a Han Chinese cohort with amyotrophic lateral sclerosis in Taiwan.

Mutations in the annexin A11 gene (ANXA11) have been recently identified in British patients and Italian patients with amyotrophic lateral sclerosis (ALS), and their role in other ALS populations remains unclear. The aim of this study was to investigate the ANXA11 mutations in a Taiwanese ALS cohort. Mutational analysis of ANXA11 was performed in 286 unrelated Taiwanese patients with ALS by Sanger sequencing. Eight ANXA11 missense variants were identified initially, and only one of them was absent from population databases. This missense variant, p.Q362L, was identified in 1 single patient with apparently sporadic ALS, and no further strong evidence was available to support its pathogenicity. Therefore, it is classified as a variant of uncertain significance. Our data indicate that pathogenic ANXA11 mutations are absent or rare in ALS patients in Taiwan.

ANXA11 mutations prevail in Chinese ALS patients with and without cognitive dementia.

ObjectiveTo investigate the genetic contribution of ANXA11, a gene associated with amyotrophic lateral sclerosis (ALS), in Chinese ALS patients with and without cognitive dementia.MethodsSequencing all the coding exons of ANXA11 and intron-exon boundaries in 18 familial amyotrophic lateral sclerosis (FALS), 353 unrelated sporadic amyotrophic lateral sclerosis (SALS), and 12 Chinese patients with ALS-frontotemporal lobar dementia (ALS-FTD). The transcripts in peripheral blood generated from a splicing mutation were examined by reverse transcriptase PCR.ResultsWe identified 6 nonsynonymous heterozygous mutations (5 novel and 1 recurrent), 1 splice site mutation, and 1 deletion of 10 amino acids (not accounted in the mutant frequency) in 11 unrelated patients, accounting for a mutant frequency of 5.6% (1/18) in FALS, 2.3% (8/353) in SALS, and 8.3% (1/12) in ALS-FTD. The deletion of 10 amino acids was detected in 1 clinically undetermined male with an ALS family history who had atrophy in hand muscles and myotonic discharges revealed by EMG. The novel p. P36R mutation was identified in 1 FALS index, 1 patient with SALS, and 1 ALS-FTD. The splicing mutation (c.174-2A>G) caused in-frame skipping of the entire exon 6. The rest missense mutations including p.D40G, p.V128M, p.S229R, p.R302C and p.G491R were found in 6 unrelated patients with SALS.ConclusionsThe ANXA11 gene is one of the most frequently mutated genes in Chinese patients with SALS. A canonical splice site mutation leading to skipping of the entire exon 6 further supports the loss-of-function mechanism. In addition, the study findings further expand the ANXA11 phenotype, first highlighting its pathogenic role in ALS-FTD.

S55. ANXA11 mutations prevail in Chinese ALS patients with and without cognitive dementia

Introduction Amyotrophic lateral sclerosis (ALS) is a fatal neurological disease characterized by progressive paralysis and ultimately respiratory failure within 5 years of symptom onset. Approximately 5–10% of ALS cases exhibit familial inheritance (FALS) and causative gene mutations can be found in 60% of FALS patients. The remaining 90–95% of ALS cases show sporadic manner (SALS) and mutations in the same genes are responsible for 10% of SALS patients. To date, rare variants in more than 30 genes have been reported to cause or be associated with ALS. Recently, Smith and et al. identified mutations in ANXA11 in ALS patients of European ancestry but pathogenicity of ANXA11 in other ALS cohorts remained unproved. In the current study, we investigated ANXA11 mutations in Chinese ALS patients with or without cognitive decline. Methods: Study population A total of 383 Chinese ALS patients were recruited at ALS clinic of Neurology Department, Peking Union Medical College Hospital (PUMCH) from January 2016 to August 2017. Mutation screening All coding exons and at least 100 bp of flanking introns of ANXA11(NM_145869) were sequenced using ABI 3730 automated DNA-sequencing system. Rare variants (MAF Transcripts investigation of the splicing mutation Total RNA was extracted using TRIzol (Invitrogen) from peripheral white blood cells. Then 2.5 μ g RNA were used to perform Reverse transcriptase-PCR. cDNA was amplified using primer pair ANXA11-RT-F(5′-CCATGAGCTACCCTGGCTAT-3′) and ANXA11-RT-R(5′-GACTCCCCAGGCAGTCAAT-3′) locating at ANXA11 exon 4 and exon 8 (shown in Fig. 3), respectively. The PCR products were isolated on a 1.5% agarose gel. DNA fragments of interest were gel-purified and sequenced. Results We identified 6 nonsynonymous heterozygous mutations (c.107C>G, p.P36R; c.119A>G, p.D40G; c.382G>A, p.V128M; c.687T>A, p.S229R; c.904C>T, p.R302C; c.1471G>A, p.G491R) and 1 splice-site mutation(c.174-2A>G, p.A58_Q187del) in 10 unrelated patients, accounting for a mutant frequency of 5.6% (1/18) in FALS, 2.3% (8/353) in SALS and 8.3% (1/12) in ALS-FTD. A novel p. P36R mutation was identified in one FALS index, one SALS patient and one ALS-FTD. The splicing mutation(c.174-2A>G) caused in-frame skipping of the entire exon 6 and further supported the loss-of-function mechanism. Conclusion ANXA11 gene is the most frequently mutated genes in Chinese patients with SALS. The study findings further expand the ANXA11 phenotype, firstly highlighting its pathogenic role in ALS-FTD.

IL12RB2 Gene Is Associated with the Age of Type 1 Diabetes Onset in Croatian Family Trios

BackgroundCommon complex diseases are influenced by both genetic and environmental factors. Many genetic factors overlap between various autoimmune diseases. The aim of the present study is to determine whether four genetic variants known to be risk variants for several autoimmune diseases could be associated with an increased susceptibility to type 1 diabetes mellitus.Methods and FindingsWe genotyped four genetic variants (rs2358817, rs1049550, rs6679356, rs9865818) within VTCN1, ANXA11, IL12RB2 and LPP genes respectively, in 265 T1DM family trios in Croatian population. We did not detect association of these polymorphisms with T1DM. However, quantitative transmission disequilibrium test (QTDT, orthogonal model) revealed a significant association between the age of onset of T1DM and IL12RB2 rs6679356 variant. An earlier onset of T1DM was associated with the rs6679356 minor dominant allele C (p = 0.005). The association remained significant even after the Bonferroni correction for multiple testing and permutation.ConclusionsVariants originally associated with juvenile idiopathic arthritis (VTCN1 gene), sarcoidosis (ANXA11 gene), primary biliary cirrhosis (IL12RB2 gene) and celiac disease (LPP gene) were not associated with type 1 diabetes in our dataset. Nevertheless, association of IL12RB2 rs6679356 polymorphism with the age of T1DM onset suggests that this gene plays a role in defining the time of disease onset.

Fine-mapping in African-American women confirms the importance of the 10p12 locus to sarcoidosis

Sarcoidosis is a chronic granulomatous disease with a wide spectrum of symptoms. Genome-wide association studies in European populations have reported significant associations between sarcoidosis and single nucleotide polymorphisms (SNPs) located in the inter-genic region between the C10ORF67 and OTUD1 genes on chromosome 10p12, and the ANXA11 gene (chromosome 10q22). We carried out fine-mapping at 10p12 and 10q22 to assess associations of genetic variants in those regions with sarcoidosis risk in African American women, based on 486 sarcoidosis cases and 943 age- and geography-matched controls in a nested case-control study within the Black Women’s Health Study. There were no significant associations with variants of the ANXA11 gene (P=0.17). Haplotypic analyses of the C10ORF67-OTUD1 inter-genic region revealed a strong inverse association of the variants rs1398024 and rs11013452 with sarcoidosis (OR=0.52; P=0.01). Both SNPs are located inside a ~300 kb low recombination region of chromosome 10p12, suggesting that both SNPs are tagging the same causal variant. Our top SNP (rs11013452) is located inside a smaller LD block in HapMap YRI, further narrowing the position of the causal SNP to a region of ~ 8kb on chromosome 10p12. The present findings confirm the potential importance of the 10p12 locus in the etiology of sarcoidosis.

Annexin A11 (ANXA11) Gene Structure as the Progenitor of Paralogous Annexins and Source of Orthologous cDNA Isoforms

The genomic organization of the annexin A11 gene was determined in mouse and human to assess its congruity with other family members and to examine the species variation in alternative splicing patterns. Mouse annexin A11 genomic clones were characterized by restriction analysis, Southern blotting, and DNA sequencing, and the homologous human gene (HGMW-approved gene symbol ANXA11) was deciphered from high-throughput genomic sequence with coanalysis of expressed sequence tags. Exons 6–15 of the tetrad core repeat region differ from annexins A7 and A13 but are spliced identically to other phylogenetic descendents, making annexin A11 the putative primary progenitor of up to nine paralogous human annexins. The 5′ regions consist of untranslated exon 1, followed by an extensive intron 1 comprising almost half the total gene length of >40 kb, and additional GC-rich exons 2–5 encoding the proline- and glycine-rich amino-terminus. Distinct cDNA isoforms in cow and human were determined to be unique to each species and hence of dubious general significance for this gene's function. Multiple transcription start sites were revealed by primer extension analysis of the mouse gene, and transfection constructs containing the prospective promoter generated transcriptional activity comparable to that of the SV40 promoter. Internal repetitive elements and vicinal gene markers were mapped for the complete human annexin A11 gene sequence to characterize the surrounding genomic environment.