A novel c.5308_5311delGAGA mutation in Senataxin in a Cypriot family with an autosomal recessive cerebellar ataxia

<p>Abstract</p> <p>Background</p> <p>Senataxin (chromosome 9q34) was recently identified as the causative gene for an autosomal recessive form of Ataxia (ARCA), termed as Ataxia with Oculomotor Apraxia, type 2 (AOA2) and characterized by generalized incoordination, cerebellar atrophy, peripheral neuropathy, "oculomotor apraxia" and increased alpha-fetoprotein (AFP). Here, we report a novel Senataxin mutation in a Cypriot ARCA family.</p> <p>Methods</p> <p>We studied several Cypriot autosomal recessive cerebellar ataxia (ARCA) families for linkage to known ARCA gene loci. We linked one family (909) to the SETX locus on chromosome 9q34 and screened the proband for mutations by direct sequencing.</p> <p>Results</p> <p>Sequence analysis revealed a novel c.5308_5311delGAGA mutation in exon 11 of the SETX gene. The mutation has not been detected in 204 control chromosomes from the Cypriot population, the remaining Cypriot ARCA families and 37 Cypriot sporadic cerebellar ataxia patients.</p> <p>Conclusion</p> <p>We identified a novel SETX homozygous c.5308_5311delGAGA mutation that co-segregates with ARCA with cerebellar atrophy and raised AFP.</p

The influence of environmental risk factors in the development of ALS in the Mediterranean Island of Cyprus

IntroductionAmyotrophic lateral sclerosis (ALS) is a devastating, uniformly lethal degenerative disease of motor neurons, presenting with relentlessly progressive muscle atrophy and weakness. The etiology of ALS remains unexplained for over 85% of all cases, suggesting that besides the genetic basis of the disease, various environmental factors are implicated in the pathogenesis of ALS. This study aimed to investigate the contribution of known environmental risk factors of ALS in the Cypriot population.MethodsWe conducted a case–control study with a total of 56 ALS cases and 56 healthy gender/age-matched controls of Cypriot nationality. Demographic, lifestyle characteristics, medical conditions, and environmental exposures were collected through the use of a detailed questionnaire. Statistical analyses using the R programming language examined the association between the above environmental factors and ALS.ResultsA chi-square test analysis revealed a statistically significant (p = 0.000461) difference in smoking status between the two groups. In addition, univariate logistic regression analysis showed a statistically significant association between ALS cases for head trauma/injury (p = 0.0398) and exposure to chemicals (p = 0.00128), compared to controls.ConclusionThis case–control investigation has shed some light on the epidemiological data of ALS in Cyprus, by identifying environmental determinants of ALS, such as smoking, head trauma, and chemical exposure, in the Cypriot population

Spinal muscular atrophy type I associated with a novel SMN1 splicing variant that disrupts the expression of the functional transcript

IntroductionSpinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by pathogenic variants in the SMN1 gene. The majority of SMA patients harbor a homozygous deletion of SMN1 exon 7 (95%). Heterozygosity for a conventional variant and a deletion is rare (5%) and not easily detected, due to the highly homologous SMN2 gene interference. SMN2 mainly produces a truncated non-functional protein (SMN-d7) instead of the full-length functional (SMN-FL). We hereby report a novel SMN1 splicing variant in an infant with severe SMA.MethodsMLPA was used for SMN1/2 exon dosage determination. Sanger sequencing approaches and long-range PCR were employed to search for an SMN1 variant. Conventional and improved Real-time PCR assays were developed for the qualitative and quantitative SMN1/2 RNA analysis.ResultsThe novel SMN1 splice-site variant c.835-8_835-5delinsG, was identified in compound heterozygosity with SMN1 exons 7/8 deletion. RNA studies revealed complete absence of SMN1 exon 7, thus confirming a disruptive effect of the variant on SMN1 splicing. No expression of the functional SMN1-FL transcript, remarkable expression of the SMN1-d7 and increased levels of the SMN2-FL/SMN2-d7 transcripts were observed.DiscussionWe verified the occurrence of a non-deletion SMN1 variant and supported its pathogenicity, thus expanding the SMN1 variants spectrum. We discuss the updated SMA genetic findings in the Cypriot population, highlighting an increased percentage of intragenic variants compared to other populations

Down-Regulation of Myogenin Can Reverse Terminal Muscle Cell Differentiation

Certain higher vertebrates developed the ability to reverse muscle cell differentiation (dedifferentiation) as an additional mechanism to regenerate muscle. Mammals, on the other hand, show limited ability to reverse muscle cell differentiation. Myogenic Regulatory Factors (MRFs), MyoD, myogenin, Myf5 and Myf6 are basic-helix-loop-helix (bHLH) transcription factors essential towards the regulation of myogenesis

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Molecular genetic study of hereditary polyneyropathy Charcot - Marie - Tooth (CMT)

Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy with a prevalence of 17-40 per 100,000. CMT is classified into demyelinating, axonal and intermediate types. Inheritance can be autosomal dominant, recessive or X-linked. The typical phenotype includes high steppage gait, foot deformities, distal sensory loss, and decreased or absent tendon reflexes. A large number of mutations in 25 causative genes that are expressed either by myelinating Schwann cells, axons, or both have thus far been described. We studied epidemiological, clinical and genetic characteristics of CMT in the Cypriot population. The prevalence of CMT on 15th January 2009 is estimated at 16/100,000. Thirty-three families and eight sporadic patients were ascertained. CMT was demyelining in 52%, axonal in 33% and intermediate in 15% of patients. Thirteen families had the PMP22 duplication, three families had the PMP22 S22F mutation, four families had GJB1/Cx32 mutations, two families had different MPZ mutations, one of them novel, and two families had different MFN2 mutations. Nine families and eight sporadic patients were excluded from the common CMT genes. We further studied six new Cypriot families, five families and four sporadic patients from Thessaly. Two Cypriot families had the PMP22 S22F mutation and 2 Greek families had the PMP22 duplication. The remaining patients should be further analyzed based on their clinical findings. In conclusion, the most frequent CMT mutation worldwide, the PMP22 duplication, is also the most frequent CMT mutation in the Cypriot population. Five out of the eight other mutations are novel, not reported in other populations.Η νόσος Charcot-Marie-Tooth (CMT) είναι η συχνότερη κληρονομική νευρολογική πάθηση με συχνότητα 17-40/100,000. Ταξινομείται στον απομυελινωτικό, αξονικό και μεικτό τύπο και κληρονομείται με επικρατητικό, υπολειπόμενο και φυλοσύνδετο τύπο. Τα κύρια χαρακτηριστικά της πάθησης είναι η αδυναμία των περιφερικών μυών των κάτω άκρων με τη χαρακτηριστική παραμόρφωση του άκρου ποδός (pes cavus), περιφερική αδυναμία των μυών των άνω άκρων και σε μικρότερο βαθμό αισθητικές διαταραχές. Έχουν αναγνωριστεί μέχρι σήμερα περίπου 25 γονίδια με μεγάλο αριθμό μεταλλάξεων, τα οποία ενέχονται στην αιτιοπαθογένεια της νόσου με έκφραση, είτε στα κύτταρα του Schwann, είτε στους άξονες ή και στα δύο. Στα πλαίσια της παρούσας διδακτορικής διατριβής διεξάχθηκε επιδημιολογική μελέτη της CMT στον Κυπριακό πληθυσμό. Διαγνώστηκαν 13 οικογένειες με το διπλασιασμό του γονιδίου PMP22, τρεις οικογένειες με σημειακή μετάλλαξη στο γονίδιο PMP22, τέσσερις οικογένειες με σημειακές μεταλλάξεις στο γονίδιο GJB1 (Cx32), δύο με σημειακές μεταλλάξεις στο γονίδιο MPZ και δύο με σημειακές μεταλλάξεις στο γονίδιο MFN2. Εννέα οικογένειες και οκτώ σποραδικοί ασθενείς αποκλείστηκαν από τα γνωστά γονίδια της CMT και χρήζουν περαιτέρω διερεύνησης. Επίσης μελετήθηκαν επιπρόσθετα έξι νέες οικογένειες και δύο νέοι ασθενείς υφιστάμενης οικογένειας από την Κύπρο καθώς και πέντε οικογένειες και τέσσερις σποραδικοί ασθενείς από τη Θεσσαλία. Από αυτές βρέθηκαν δύο νέες οικογένειες με τη μετάλλαξη S22F στο γονίδιο PMP22 και δυο οικογένειες από την Ελλάδα με διπλασιασμό του γονιδίου PMP22. Οι υπόλοιποι ασθενείς χρήζουν περαιτέρω διερεύνησης. Συμπερασματικά, η συχνότερη μετάλλαξη, όπως και παγκοσμίως, είναι ο διπλασιασμός του γονιδίου PMP22, καθώς επίσης και η παρουσία πέντε νέων μεταλλάξεων στον Κυπριακό πληθυσμό

Deregulation of LRSAM1 expression impairs the levels of TSG101, UBE2N, VPS28, MDM2 and EGFR.

CMT is the most common hereditary neuromuscular disorder of the peripheral nervous system with a prevalence of 1/2500 individuals and it is caused by mutations in more than 80 genes. LRSAM1, a RING finger ubiquitin ligase also known as TSG101-associated ligase (TAL), has been associated with Charcot-Marie-Tooth disease type 2P (CMT2P) and to date eight causative mutations have been identified. Little is currently known on the pathogenetic mechanisms that lead to the disease. We investigated the effect of LRSAM1 deregulation on possible LRSAM1 interacting molecules in cell based models. Possible LRSAM1 interacting molecules were identified using protein-protein interaction databases and literature data. Expression analysis of these molecules was performed in both CMT2P patient and control lymphoblastoid cell lines as well as in LRSAM1 and TSG101 downregulated SH-SY5Y cells.TSG101, UBE2N, VPS28, EGFR and MDM2 levels were significantly decreased in the CMT2P patient lymphoblastoid cell line as well as in LRSAM1 downregulated cells. TSG101 downregulation had a significant effect only on the expression of VPS28 and MDM2 and it did not affect the levels of LRSAM1. This study confirms that LRSAM1 is a regulator of TSG101 expression. Furthermore, deregulation of LRSAM1 significantly affects the levels of UBE2N, VPS28, EGFR and MDM2