- MeSH
- autoimunitní hemolytická anemie farmakoterapie genetika MeSH
- beta-globiny genetika izolace a purifikace MeSH
- bronchiální astma genetika MeSH
- buněčná diferenciace MeSH
- chelátory železa terapeutické užití MeSH
- dítě MeSH
- erythropoetin metabolismus MeSH
- erytrocyty fyziologie MeSH
- erytropoéza genetika MeSH
- kultivované buňky MeSH
- lidé MeSH
- proliferace buněk MeSH
- receptory erythropoetinu metabolismus MeSH
- regulace genové exprese MeSH
- sekvenování exomu MeSH
- signální transdukce MeSH
- stupeň závažnosti nemoci MeSH
- transkripční faktor STAT3 genetika MeSH
- transkripční faktor STAT5 metabolismus MeSH
- zárodečné mutace genetika MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- dopisy MeSH
- práce podpořená grantem MeSH
We report an infant with sickle cell disease phenotype by biochemical analysis whose β-globin gene (HBB) sequencing showed sickle cell mutation (HBBS ) heterozygosity. The proband has a unique head-to-tail duplication of the β-globin gene cluster having wild-type (HBBA ) and HBBS alleles inherited from her father; constituting her HBBS /HBBS -HBBA genotype. Further analyses revealed that proband's duplicated β-globin gene cluster (∼650 kb) encompassing HBBA does not include the immediate upstream locus control region (LCR) or 3' DNase I hypersensitivity (HS) element. The LCR interacts with β-globin gene cluster involving long range DNA interactions mediated by various transcription factors to drive the regulation of globin genes expression. However, a low level of HBBA transcript was clearly detected by digital PCR. In this patient, the observed transcription from the duplicated, distally displaced HBBA cluster demonstrates that the loss of LCR and flanking 3'HS sites do not lead to complete silencing of HBB transcription.
- MeSH
- 3' přiléhající oblast DNA MeSH
- beta-globiny genetika MeSH
- duplicitní geny * MeSH
- genetická transkripce MeSH
- kojenec MeSH
- lidé MeSH
- mutace MeSH
- regulační oblast lokusu (genu) MeSH
- srpkovitá anemie genetika MeSH
- umlčování genů MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
β-Thalassemia (β-thal) is considered rare in Central Europe. As in other malaria-free regions, the presence of β-thal in Central Europe reflects historical and recent immigration, and demographic changes that have influenced the genetic variability of the current populations living in this area. This study assesses the frequency and spectrum of mutations on the β-globin gene in Czech and Slovak subjects with clinical symptoms of thalassemia. The results of the initial part of this research were published more than two decades ago; the aim of this study was to update these original reports. During the period from 2002 to 2015, 400 cases from Czech and Slovak hematological centers were analyzed. Twenty-nine β-thal mutations, identified in 356 heterozygotes from 218 unrelated families, involve five unique mutations including a recently described insertion of a transposable L1 element into the β-globin gene. One mutation described here is reported for the first time. Most of the mutations were of Mediterranean origin and accounted for 82.0% of cases. All but one case studied were heterozygous carriers, manifesting β-thal minor, with rare exceptions represented by the rare (β(0)) codons 46/47 (+G) (HBB: c.142_142dupG) mutation associated with an α-globin gene quadruplication and by dominantly inherited β-thal with a more severe phenotype. One double heterozygous β-thal patient was a recent immigrant from Moldavia. The list of δβ-thal alleles (26 carriers, 16 families) contains Hb Lepore and two types of δβ(0)-thal deletions. In the past, genetic drift and migration as well as recent immigrations were responsible for the introduction of Mediterranean alleles, while several mutations described in single families were of local origin.
- MeSH
- Asijci etnologie genetika MeSH
- běloši etnologie genetika MeSH
- beta-globiny genetika MeSH
- beta-talasemie epidemiologie genetika MeSH
- emigrace a imigrace MeSH
- frekvence genu MeSH
- genetický drift MeSH
- heterozygot MeSH
- lidé MeSH
- molekulární epidemiologie * MeSH
- mutace * MeSH
- rodokmen MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
- Slovenská republika epidemiologie MeSH
Mutations in SNRP200 gene cause autosomal-dominant retinal disorder retinitis pigmentosa (RP). The protein product of SNRNP200 is BRR2, a DExD/H box RNA helicase crucial for pre-mRNA splicing. In this study, we prepared p.S1087L and p.R1090L mutations of human BRR2 using bacterial artificial chromosome recombineering and stably expressed them in human cell culture. Mutations in BRR2 did not compromise snRNP assembly and both mutants were incorporated into the spliceosome just as the wild-type (wt) protein. Surprisingly, cells expressing RP mutants exhibited increased splicing efficiency of the LDHA gene. Next, we found that depletion of endogenous BRR2 enhanced usage of a β-globin cryptic splice site while splicing at the correct splice site was inhibited. Proper splicing of optimal and cryptic splice sites was restored in cells expressing BRR2-wt but not in cells expressing RP mutants. Taken together, our data suggest that BRR2 is an important factor in 5'-splice-site recognition and that the RP-linked mutations c.3260C>T (p.S1087L) and c.3269G>T (p.R1090L) affect this BRR2 function.
- MeSH
- alternativní sestřih MeSH
- beta-globiny genetika metabolismus MeSH
- HeLa buňky MeSH
- klonování DNA MeSH
- lidé MeSH
- místa sestřihu RNA genetika MeSH
- mutace * MeSH
- prekurzory RNA genetika metabolismus MeSH
- reportérové geny MeSH
- retinopathia pigmentosa genetika MeSH
- ribonukleoproteiny malé jaderné genetika MeSH
- RNA-helikasy genetika MeSH
- spliceozomy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We describe the molecular etiology of β(+)-thalassemia that is caused by the insertion of the full-length transposable element LINE-1 (L1) into the intron-2 of the β-globin gene (HBB). The transcript level of the affected β-globin gene was severely reduced. The remaining transcripts consisted of full-length, correctly processed β-globin mRNA and a minute amount of three aberrantly spliced transcripts with a decreased half-life due to activation of the nonsense-mediated decay pathway. The lower steady-state amount of mRNA produced by the β-globin(L1) allele also resulted from a reduced rate of transcription and decreased production of full-length β-globin primary transcripts. The promoter and enhancer sequences of the β-globin(L1) allele were hypermethylated; however, treatment with a demethylating agent did not restore the impaired transcription. A histone deacetylase inhibitor partially reactivated the β-globin(L1) transcription despite permanent β-globin(L1) promoter CpG methylation. This result indicates that the decreased rate of transcription from the β-globin(L1) allele is associated with an altered chromatin structure. Therefore, the molecular defect caused by intronic L1 insertion in the β-globin gene represents a novel etiology of β-thalassemia.
- MeSH
- alely MeSH
- alternativní sestřih MeSH
- beta-globiny genetika MeSH
- beta-talasemie genetika MeSH
- CpG ostrůvky MeSH
- dlouhé rozptýlené jaderné elementy * MeSH
- dospělí MeSH
- genetická transkripce MeSH
- introny * MeSH
- inzerční mutageneze * MeSH
- lidé MeSH
- metylace DNA MeSH
- pořadí genů MeSH
- promotorové oblasti (genetika) MeSH
- regulace genové exprese MeSH
- stabilita RNA MeSH
- umlčování genů MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
BACKGROUND: Beta-thalassaemia is a congenital disorder caused by point mutations in a haemoglobin beta-globin chain. The heterozygous form produces microcytosis and normal iron levels, however, haemoglobin electrophoresis shows elevated amounts of haemoglobin A2 and eventually foetal haemoglobin F as well. METHODS: Between 2005-2011, in three centres in Slovakia, carriers of beta-thalassaemic genes or other haemoglobinopathies were searched for. Diagnosis was performed by haematologists whereby the family history was evaluated, together with the overall clinical condition, blood count and blood smear, iron parameters, haemolysis and haemoglobin electrophoresis testing. A proportion of patients was examined by molecular genetic methods. RESULTS: A clinical suspicion of the heterozygous form of beta-thalassaemia was documented in 402 patients (21.9%) out of a total of 1,834 examinations. From these patients, 87 underwent molecular genetic testing and mutations of beta globin genes were identified in 70 of them, where the most frequent mutations were IVS 2.1 (28.5%), IVS 1.110 (25.6%) and IVS 1.1 (11.3%). Evidence of haemoglobin S (sickle cell anaemia) was also notable in one case (patient of African origin). Unusually high levels of haemoglobin F (6-21%) were found in 23 adult subjects. CONCLUSION: The study showed that there is a higher number of heterozygotes for beta-thalassaemia and rarely haemoglobinopathies. It is necessary to continue in search of pathological gene carriers in Slovakia.
- MeSH
- beta-globiny genetika MeSH
- beta-talasemie diagnóza epidemiologie genetika MeSH
- dítě MeSH
- dospělí MeSH
- hemoglobinopatie diagnóza epidemiologie genetika MeSH
- heterozygot MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- molekulární biologie MeSH
- mutace MeSH
- předškolní dítě MeSH
- senioři MeSH
- srpkovitá anemie diagnóza epidemiologie genetika MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Slovenská republika MeSH
This study evaluated quantification of fetal extracellular DNA in maternal plasma for differentiation between cases at risk of onset of placental-insufficiency-related complications and normal pregnancies. Using real-time polymerase chain reaction, fetal (sex-determining region Y [SRY] and hypermethylated RASSF1A sequence) and total (beta-globin [GLO] gene) extracellular DNA was examined in 70 normal pregnancies, 18 at risk of placental-insufficiency-related pregnancy complications, 24 preeclampsia with or without (w or w/o) intrauterine growth retardation (IUGR) (median 34.0 week), and 11 IUGR (median 28.5 week). IUGR was diagnosed when estimated fetal weight was below the 10th percentile for evaluated gestational age. Although increased levels of extracellular DNA were detected in pregnancies with preeclampsia w or w/o IUGR relative to controls (RASSF1A, p < 0.001; SRY, p = 0.009; GLO, p < 0.001), quantities of fetal extracellular DNA in IUGR were not statistically significant (RASSF1A, p = 0.21; SRY, p = 0.2). RASSF1A, SRY, and GLO achieved 93.1%, 93.6%, and 92.1% accuracy for differentiation between normal pregnancy and preeclampsia w or w/o IUGR. Lower sensitivity was observed for pregnancies with onset of IUGR (RASSF1A, 60.0%; SRY, 80.0%; GLO, 72.7%), but did not influence final accuracy (RASSF1A, 91.6%; SRY, 92.5%; GLO, 89.5%). Among 18 patients at risk, 8 pregnancies involving 3 female and 5 male fetuses developed preeclampsia (n = 4), IUGR (n = 3), and chronic placentopathy causing hypoxia (n = 1). Elevation of extracellular DNA was demonstrated in 3/5 (SRY), 1/8 (hypermethylated RASSF1A), and 4/8 (GLO) patients at the earliest 26 weeks and at the latest 2 weeks before the onset of symptoms. These data indicate that fetal and total extracellular DNA concentrations can be significantly elevated in plasma of patients who later developed placental-insufficiency-related pregnancy complications. However, this is strongly individualized, and not a rule for all cases, and probably depends on the actual occurrence of excessive placental trophoblast apoptosis.
- MeSH
- beta-globiny genetika metabolismus MeSH
- časové faktory MeSH
- DNA genetika MeSH
- extracelulární prostor genetika MeSH
- genetické markery genetika MeSH
- lidé MeSH
- matky MeSH
- metylace DNA MeSH
- nádorové supresorové proteiny krev genetika MeSH
- placentární insuficience krev diagnóza genetika MeSH
- plod cytologie MeSH
- protein oblasti určující pohlaví na chromozomu Y krev genetika MeSH
- riziko MeSH
- studie případů a kontrol MeSH
- těhotenství MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH