Mutations in the C1 inhibitor (C1INH) encoding gene, SERPING1, are associated with hereditary angioedema (HAE) which manifests as recurrent submucosal and subcutaneous edema episodes. The major C1INH function is the complement system inhibition, preventing its spontaneous activation. The presented study is focused on SERPING1 exon 3, an alternative and extraordinarily long exon (499 bp). Endogenous expression analysis performed in the HepG2, human liver, and human peripheral blood cells revealed several exon 3 splicing variants alongside exon inclusion: a highly prevalent exon skipping variant and less frequent +38 and -15 variants with alternative 3' splice sites (ss) located 38 and 15 nucleotides downstream and upstream from the authentic 3' ss, respectively. An exon skipping variant introducing a premature stop codon, represented nearly one third of all splicing variants and surprisingly appeared not to be degraded by NMD. The alternative -15 3' ss was used to a small extent, although predicted to be extremely weak. Its use was shown to be independent of its strength and highly sensitive to any changes in the surrounding sequence. -15 3' ss seems to be co-regulated with the authentic 3' ss, whose use is dependent mainly on its strength and less on the presence of intronic regulatory motifs. Subtle SERPING1 exon 3 splicing regulation can contribute to overall C1INH plasma levels and HAE pathogenesis.

• Klíčová slova
• Acceptor splice site, Alternative splicing, Exon 3, Hereditary angioedema, SERPING1,
• MeSH
• alternativní sestřih genetika   MeSH
• buněčné jádro genetika   MeSH
• buňky Hep G2 MeSH
• exony genetika   MeSH
• inhibiční protein komplementu C1 genetika   MeSH
• lidé MeSH
• malá interferující RNA metabolismus   MeSH
• místa sestřihu RNA genetika   MeSH
• mutace genetika   MeSH
• nonsense mediated mRNA decay genetika   MeSH
• sekvence nukleotidů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inhibiční protein komplementu C1 MeSH
• malá interferující RNA MeSH
• místa sestřihu RNA MeSH
• SERPING1 protein, human MeSH Prohlížeč

PURPOSE: Hereditary angioedema (HAE) is a rare autosomal dominant life-threatening disease characterized by low levels of C1 inhibitor (type I HAE) or normal levels of ineffective C1 inhibitor (type II HAE), typically occurring as a consequence of a SERPING1 mutation. In some cases, a causal mutation remains undetected after using a standard molecular genetic analysis. RESULTS: Here we show a long methodological way to the final discovery of c.1029 + 384A > G, a novel deep intronic mutation in intron 6 which is responsible for HAE type I in a large family and has not been identified by a conventional diagnostic approach. This mutation results in de novo donor splice site creation and subsequent pseudoexon inclusion, the mechanism firstly described to occur in SERPING1 in this study. We additionally discovered that the proximal part of intron 6 is a region potentially prone to pseudoexon-activating mutations, since natural alternative exons and additional cryptic sites occur therein. Indeed, we confirmed the existence of at least two different alternative exons in this region not described previously. CONCLUSIONS: In conclusion, our results suggest that detecting aberrant transcripts, which are often low abundant because of nonsense-mediated decay, requires a modified methodological approach. We suggest SERPING1 intron 6 sequencing and/or tailored mRNA analysis to be routinely used in HAE patients with no mutation identified in the coding sequence.

• Klíčová slova
• Hereditary angioedema, SERPING1, donor splice site, pre-mRNA splicing, pseudoexon activation,
• MeSH
• dítě MeSH
• dospělí MeSH
• exony genetika   MeSH
• hereditární angioedém, typy I a II genetika   MeSH
• inhibiční protein komplementu C1 genetika   MeSH
• introny genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• místa sestřihu RNA genetika   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mutace genetika   MeSH
• mutační analýza DNA metody   MeSH
• rodokmen MeSH
• senioři MeSH
• splicing proteinů genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inhibiční protein komplementu C1 MeSH
• místa sestřihu RNA MeSH

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare and life-threatening condition characterized by recurrent localized edema. We conducted a systematic screening of SERPING1 defects in a cohort of 207 Czech patients from 85 families with C1-INH-HAE. Our workflow involved a combined strategy of sequencing extended to UTR and deep intronic regions, advanced in silico prediction tools, and mRNA-based functional assays. This approach allowed us to detect a causal variant in all families except one and to identify a total of 56 different variants, including 5 novel variants that are likely to be causal. We further investigated the functional impact of two splicing variants, namely c.550 + 3A > C and c.686-7C > G using minigene assays and RT-PCR mRNA analysis. Notably, our cohort showed a considerably higher proportion of detected splicing variants compared to other central European populations and the LOVD database. Moreover, our findings revealed a significant association between HAE type 1 missense variants and a delayed HAE onset when compared to null variants. We also observed a significant correlation between the presence of the SERPING1 variant c.-21 T > C in the trans position to causal variants and the frequency of attacks per year, disease onset, as well as Clinical severity score. Overall, our study provides new insights into the genetic landscape of C1-INH-HAE in the Czech population, including the identification of novel variants and a better understanding of genotype-phenotype correlations. Our findings also highlight the importance of comprehensive screening strategies and functional analyses in improving the C1-INH-HAE diagnosis and management.

• Klíčová slova
• C1-INH-HAE, HAE, SERPING1, genotype–phenotype relationship, hereditary angioedema, splicing, time to diagnosis,
• MeSH
• hereditární angioedémy * diagnóza   epidemiologie   genetika   MeSH
• inhibiční protein komplementu C1 * genetika   MeSH
• lidé MeSH
• messenger RNA MeSH
• sestřih RNA MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• inhibiční protein komplementu C1 * MeSH
• messenger RNA MeSH
• SERPING1 protein, human MeSH Prohlížeč

Hereditary angioedema with C1 Inhibitor deficiency (C1-INH-HAE) is caused by a constellation of variants of the SERPING1 gene (n = 809; 1,494 pedigrees), accounting for 86.8% of HAE families, showing a pronounced mutagenic liability of SERPING1 and pertaining to 5.6% de novo variants. C1-INH is the major control serpin of the kallikrein-kinin system (KKS). In addition, C1-INH controls complement C1 and plasminogen activation, both systems contributing to inflammation. Recognizing the failed control of C1s protease or KKS provides the diagnosis of C1-INH-HAE. SERPING1 variants usually behave in an autosomal-dominant character with an incomplete penetrance and a low prevalence. A great majority of variants (809/893; 90.5%) that were introduced into online database have been considered as pathogenic/likely pathogenic. Haploinsufficiency is a common feature in C1-INH-HAE where a dominant-negative variant product impacts the wild-type allele and renders it inactive. Small (36.2%) and large (8.3%) deletions/duplications are common, with exon 4 as the most affected one. Point substitutions with missense variants (32.2%) are of interest for the serpin structure-function relationship. Canonical splice sites can be affected by variants within introns and exons also (14.3%). For noncanonical sequences, exon skipping has been confirmed by splicing analyses of patients' blood-derived RNAs (n = 25). Exonic variants (n = 6) can affect exon splicing. Rare deep-intron variants (n = 6), putatively acting as pseudo-exon activating mutations, have been characterized as pathogenic. Some variants have been characterized as benign/likely benign/of uncertain significance (n = 74). This category includes some homozygous (n = 10) or compound heterozygous variants (n = 11). They are presenting with minor allele frequency (MAF) below 0.00002 (i.e., lower than C1-INH-HAE frequency), and may be quantitatively unable to cause haploinsufficiency. Rare benign variants could contribute as disease modifiers. Gonadal mosaicism in C1-INH-HAE is rare and must be distinguished from a de novo variant. Situations with paternal or maternal disomy have been recorded (n = 3). Genotypes must be interpreted with biological investigation fitting with C1-INH expression and typing. Any SERPING1 variant reminiscent of the dysfunctional phenotype of serpin with multimerization or latency should be identified as serpinopathy.

• Klíčová slova
• C1 Inhibitor, C1-INH-HAE, SERPING1 gene, angioedema, genetic variation, hereditary–diagnosis, serpin function, serpinopathy,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: Hereditary angioedema (HAE) is a rare autosomal dominant genetic disease characterised by acute episodes of non-pruritic skin and submucosal swelling caused by increase in vascular permeability. OBJECTIVE: Here we present the first complex analysis of the National HAE Slovakian cohort with the detection of 12 previously un-published genetic variants in SERPING1 gene. METHODS: In patients diagnosed with hereditary angioedema caused by deficiency or dysfunction of C1 inhibitor (C1-INH-HAE) based on clinical manifestation and complement measurements, SERPING1 gene was tested by DNA sequencing (Sanger sequencing/massive parallel sequencing) and/or multiplex ligation-dependent probe amplification for detection of large rearrangements. RESULTS: The Slovakian national cohort consisted of 132 living patients with confirmed HAE. We identified 51 index cases (32 families, 19 sporadic patients/112 adults, 20 children). One hundred seventeen patients had HAE caused by deficiency of C1 inhibitor (C1-INH-HAE-1) and 15 patients had HAE caused by dysfunction of C1 inhibitor (C1-INH-HAE-2). The prevalence of HAE in Slovakia has recently been calculated to 1:41 280 which is higher than average calculated prevalence. The estimated incidence was 1:1360 000. Molecular-genetic testing of the SERPING1 gene found 22 unique causal variants in 26 index cases, including 12 previously undescribed and unreported. CONCLUSION: The first complex report about epidemiology and genetics of the Slovakian national HAE cohort expands the knowledge of the C1-INH-HAE genetics. Twelve novel causal variants were present in the half of the index cases. A higher percentage of inframe variants comparing to other studies was observed. Heterozygous deletion of exon 3 found in a large C1-INH-HAE-1 family probably causes the dysregulation of the splicing isoforms balance and leads to the decrease of full-length C1-INH level.

• Klíčová slova
• Angioedemas, Complement C1 inhibitor protein, Genetic testing, Hereditary/epidemiology, Hereditary/genetics, Slovakia,
• Publikační typ
• časopisecké články MeSH

Both variants affecting splice sites and those in splicing regulatory elements (SREs) can impair pre-mRNA splicing, eventually leading to severe diseases. Despite the availability of many prediction tools, prognosis of splicing affection is not trivial, especially when SREs are involved. Here, we present data on 92 in silico-/55 minigene-analysed variants detected in genes responsible for the primary immunodeficiencies development (namely BTK, CD40LG, IL2RG, SERPING1, STAT3, and WAS). Of 20 splicing-affecting variants, 16 affected splice site while 4 disrupted potential SRE. The presence or absence of splicing defects was confirmed in 30 of 32 blood-derived patients' RNAs. Testing prediction tools performance, splice site disruptions and creations were reliably predicted in contrast to SRE-affecting variants for which just ESRseq, ΔHZEI-scores and EX-SKIP predictions showed promising results. Next, we found an interesting pattern in cryptic splice site predictions. These results might help PID-diagnosticians and geneticists cope with potential splicing-affecting variants.

• Klíčová slova
• Cryptic splice sites, Primary immunodeficiencies, Splicing prediction, Splicing-affecting variants,
• MeSH
• buňky Hep G2 MeSH
• dítě MeSH
• exony MeSH
• HeLa buňky MeSH
• inhibiční protein komplementu C1 MeSH
• kojenec MeSH
• komplement C1 - inaktivátory genetika   MeSH
• lidé MeSH
• messenger RNA genetika   MeSH
• mutace MeSH
• předškolní dítě MeSH
• protein Wiskottova-Aldrichova syndromu genetika   MeSH
• proteinkinasa BTK MeSH
• receptory interleukinů - společná gama-podjednotka genetika   MeSH
• rekombinantní fúzní proteiny genetika   MeSH
• sestřih RNA * MeSH
• syndromy imunologické nedostatečnosti genetika   MeSH
• transkripční faktor STAT3 genetika   MeSH
• tyrosinkinasy genetika   MeSH
• U937 buňky MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• předškolní dítě MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• BTK protein, human MeSH Prohlížeč
• CD40LIg fusion protein MeSH Prohlížeč
• IL2RG protein, human MeSH Prohlížeč
• inhibiční protein komplementu C1 MeSH
• komplement C1 - inaktivátory MeSH
• messenger RNA MeSH
• protein Wiskottova-Aldrichova syndromu MeSH
• proteinkinasa BTK MeSH
• receptory interleukinů - společná gama-podjednotka MeSH
• rekombinantní fúzní proteiny MeSH
• SERPING1 protein, human MeSH Prohlížeč
• STAT3 protein, human MeSH Prohlížeč
• transkripční faktor STAT3 MeSH
• tyrosinkinasy MeSH
• WAS protein, human MeSH Prohlížeč

BACKGROUND: Hereditary angio-oedema (HAE) is manifested by repeated episodes of localised subcutaneous or sub-mucosal oedema. Symptoms are extremely variable in frequency, localisation, and severity. Atypical or mild clinical symptoms of the disease may lead to erroneous diagnosis, causing diagnostic delay. The goal of this study was to assess how diagnostic delay has changed over 33 years at a single referral centre. METHODS: We analysed diagnostic delay and first symptoms of HAE in patients who were diagnosed at an immunology department between 1980 and 2013. Patient's records were analysed. RESULTS: The median diagnostic delay in 77 HAE type 1 and 2 patients was seven (range, 0-42) years. The difference observed in diagnostic delay between probands (18 [0-42] years) and others (1 [0-37] year) was significant (p<0.001). Our data show a significant negative correlation between the length of diagnostic delay and the year of diagnosis in our group of patients (p=0.024). The median age of first symptoms among all HAE patients (N=64) was 17 (1-40) years. The first symptoms of HAE in 64 patients were analysed. Twenty-six patients had abdominal, seventeen peripheral, five facial, two urogenital, and three had laryngeal oedema as the first manifestation of the disease. The last death that was attributed to HAE was in 1977. CONCLUSIONS: Our observations demonstrate improved awareness of HAE among physicians, as documented by the significant decrease in diagnostic delay. It is believed that earlier treatment will improve patient quality of life and life expectancy.

• Klíčová slova
• Diagnostic delay, First symptoms, Hereditary angio-oedema,
• MeSH
• dítě MeSH
• dospělí MeSH
• hereditární angioedémy diagnóza   genetika   mortalita   MeSH
• inhibiční protein komplementu C1 MeSH
• kojenec MeSH
• komplement C1 - inaktivátory analýza   genetika   MeSH
• kvalita života MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nefelometrie a turbidimetrie MeSH
• opožděná diagnóza statistika a číselné údaje   MeSH
• předškolní dítě MeSH
• retrospektivní studie MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• inhibiční protein komplementu C1 MeSH
• komplement C1 - inaktivátory MeSH
• SERPING1 protein, human MeSH Prohlížeč

• MeSH
• esterasy MeSH
• hereditární angioedémy * farmakoterapie   prevence a kontrola   MeSH
• inhibiční protein komplementu C1 * terapeutické užití   MeSH
• komplement C1 - inaktivátory MeSH
• lidé MeSH
• rekombinantní proteiny MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• esterasy MeSH
• inhibiční protein komplementu C1 * MeSH
• komplement C1 - inaktivátory MeSH
• rekombinantní proteiny MeSH

INTRODUCTION: Acquired angioedema with C1 inhibitor deficiency (AAE-C1-INH) is rare but a potentially life-threatening disease. There are no official prevalence data, nor approved therapies for this condition. OBJECTIVE: In this study, we aimed to collect and analyze clinical data on patients with AAE-C1-INH in the Czech Republic. METHODS: We have conducted a retrospective analysis of AAE-C1-INH patients from Czech referral centers for the treatment of hereditary angioedema with C1 inhibitor deficiency. The inclusion criteria involved recurrent episodes of angioedema with the first manifestation at or after the age of 40, negative family history of angioedema, and C1 inhibitor function 50% or less. RESULTS: A total of 14 patients (7 males and 7 females) met the inclusion criteria for AAE-C1-INH. The median age of the symptom onset was 59.5 years, and the median diagnosis delay was 1 year. The most common clinical manifestation was facial edema (100%) and upper airway swelling (85.7%). All patients responded to the acute attack treatment with icatibant and plasma-derived or recombinant C1 inhibitor concentrate. Lymphoid malignancy was identified in 9 patients (64%), monoclonal gammopathy of uncertain significance in 3 (21%), and in 1 patient autoimmune disease (ulcerative colitis) was considered causative (7%). We were not able to identify any underlying disease only in 1 patient (7%). In 6 of 7 patients (86%) treated for lymphoma, either a reduction in the frequency of angioedema attacks or both angioedema symptoms' disappearance and complement parameter normalization was observed. CONCLUSIONS: The prevalence of AAE-C1-INH in the Czech Republic is about 1:760,000. This rare condition occurs in approximately 8% of the patients with angioedema with C1 inhibitor deficiency. AAE-C1-INH is strongly associated with lymphoproliferative disorders, and treating these conditions may improve the control of angioedema symptoms.

• Klíčová slova
• Acquired angioedema, Bradykinin, C1 inhibitor, Lymphoma,
• MeSH
• biologické markery MeSH
• dospělí MeSH
• hereditární angioedémy diagnóza   epidemiologie   etiologie   terapie   MeSH
• inhibiční protein komplementu C1 genetika   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• management nemoci MeSH
• náchylnost k nemoci MeSH
• ochrana veřejného zdraví MeSH
• retrospektivní studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• určení symptomu MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• biologické markery MeSH
• inhibiční protein komplementu C1 MeSH
• SERPING1 protein, human MeSH Prohlížeč

BACKGROUND: For the prevention of attacks of hereditary angioedema (HAE), the efficacy and safety of subcutaneous human C1-esterase inhibitor (C1-INH[SC]; HAEGARDA, CSL Behring) was established in the 16-week Clinical Study for Optimal Management of Preventing Angioedema with Low-Volume Subcutaneous C1-Inhibitor Replacement Therapy (COMPACT). OBJECTIVE: To assess the long-term safety, occurrence of angioedema attacks, and use of rescue medication with C1-INH(SC). METHODS: Open-label, randomized, parallel-arm extension of COMPACT across 11 countries. Patients with frequent angioedema attacks, either study treatment-naive or who had completed COMPACT, were randomly assigned (1:1) to 40 IU/kg or 60 IU/kg C1-INH(SC) twice per week, with conditional uptitration to optimize prophylaxis (ClinicalTrials.gov registration no. NCT02316353). RESULTS: A total of 126 patients with a monthly attack rate of 4.3 in 3 months before entry in COMPACT were enrolled and treated for a mean of 1.5 years; 44 patients (34.9%) had more than 2 years of exposure. Mean steady-state C1-INH functional activity increased to 66.6% with 60 IU/kg. Incidence of adverse events was low and similar in both dose groups (11.3 and 8.5 events per patient-year for 40 IU/kg and 60 IU/kg, respectively). For 40 IU/kg and 60 IU/kg, median annualized attack rates were 1.3 and 1.0, respectively, and median rescue medication use was 0.2 and 0.0 times per year, respectively. Of 23 patients receiving 60 IU/kg for more than 2 years, 19 (83%) were attack-free during months 25 to 30 of treatment. CONCLUSIONS: In patients with frequent HAE attacks, long-term replacement therapy with C1-INH(SC) is safe and exhibits a substantial and sustained prophylactic effect, with the vast majority of patients becoming free from debilitating disease symptoms.

• Klíčová slova
• C1-esterase inhibitor, HAEGARDA, Hereditary angioedema, Long-term, Prophylaxis, Safety, Subcutaneous,
• MeSH
• dítě MeSH
• dospělí MeSH
• hereditární angioedémy prevence a kontrola   MeSH
• inhibiční protein komplementu C1 aplikace a dávkování   MeSH
• injekce subkutánní MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• senioři MeSH
• výsledek terapie MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze III MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• inhibiční protein komplementu C1 MeSH