Epidemiology of Huntington disease in Cyprus: A 20-year retrospective study.

Huntington disease (HD) is most prevalent among populations of western European descent and isolated populations where founder effects may operate. The aim of this study was to examine the epidemiology of HD in Cyprus, an island in southern Europe with extensive western European colonization in the past. All registered HD patients in the Cyprus, since 1994, were included. Detailed pedigrees and clinical information were recorded and maps, showing the geographic distribution of HD, were constructed. Requests for genetic testing were also examined. The project identified 58 clinically manifested cases of HD belonging to 19 families. The 16 families of Cypriot origin were concentrated in a confined geographical cluster in southeast Cyprus. In 2015, prevalence of symptomatic HD was 4.64/100 000 population, while incidence was 0.12/100 000 person-years. Prevalence displayed a marked increase during the past 20 years. Disease characteristics of HD patients were similar to those reported in western European populations. Lastly, the uptake of predictive and/or prenatal testing was limited. HD disease characteristics, incidence and prevalence in Cyprus were comparable to western European populations. Together with the geographical clustering observed, these results support the possibility for a relatively recent founder effect of HD in Cyprus, potentially of western European origin.

Genetic findings of Cypriot spinal muscular atrophy patients.

Spinal muscular atrophy (SMA) is an autosomal recessive, neurodegenerative disorder characterised commonly by proximal muscle weakness and wasting in the absence of sensory signs. Deletion or disruption of the SMN1 gene causes the disease. The SMN1 gene is located within an inverted duplication on chromosome 5q13 with the genes SMN2, NAIP and GTF2H2. MLPA analysis of 13 Cypriot SMA patients revealed that, 12 patients carried a homozygous SMN1 gene deletion and one patient carried two copies of the SMN1 gene. Two of 13 cases were a consequence of a paternally originating de novo mutation. Five genotypes were identified within the population, with the most frequent being a homozygous SMN1 and NAIP genes deletion. In conclusion, genotype-phenotype correlation revealed that SMN2 is inversely related to disease severity and that NAIP and GTF2H2 act as negative modifiers. This study provided, for the first time, a comprehensive overview of gene copy numbers and inheritance patterns within Cypriot SMA families.

Charcot-Marie-Tooth type 4B is caused by mutations in the gene encoding myotubularin-related protein-2.

A gene mutated in Charcot-Marie-Tooth disease type 4B (CMT4B), an autosomal recessive demyelinating neuropathy with myelin outfoldings, has been mapped on chromosome 11q22. Using a positional-cloning strategy, we identified in unrelated CMT4B patients mutations occurring in the gene MTMR2, encoding myotubularin-related protein-2, a dual specificity phosphatase (DSP).

Huntington's disease in Greece: the experience of 14 years.

A large scale genetic and epidemiological study of Huntington's disease (HD) was carried out in Greece from January 1995 to December 2008. Diagnostic testing was carried out in 461 symptomatic individuals, while 256 were tested for presymptomatic purposes. The diagnosis of HD with a CAG expansion ≥ 36 was confirmed in 278 symptomatic individuals. The prevalence of HD in Greece was estimated at approximately 2.5 to 5.4:100,000, while the mean minimum incidence was estimated at 2.2 to 4.4 per million per year. The molecular diagnosis of HD was confirmed in the majority of patients (84.4%) sent for confirmation. The false-positive cases 15.6% were characterized by the absence of a family history of HD and the presence of an atypical clinical picture. The uptake of predictive testing for HD was 8.6%. A prenatal test was requested in six pregnancies. The findings of our study do not differ significantly from those of similar studies from other European countries despite the relative genetic isolation of Greece. Of interest is the identification of clusters of HD in Greece. The presence or absence of a family history of HD should be interpreted cautiously, during the diagnostic process.

COVID-19 enabled co-authoring networks: a country-case analysis.

In this paper we seek to examine the co-authoring pattern of a select group of researchers that are affiliated with a specific country. By way of making use of standard bibliometric analysis, we explore the publication evolution of all COVID-19-related peer reviewed papers that have been (co)-authored by researchers that are affiliated with Greek institutions. The aim is to identify its advancement over time, the institutions involved and the countries with which the co-authors are affiliated with. The timeframe of the study spans from the moment that WHO Director-General declared the novel coronavirus outbreak a public health emergency of international concern (WHO, 2020. Archived: WHO timeline-covid-19. Retrieved from Archived: Who Timeline-COVID-19. https://www.who.int/news/item/27-04-2020-who-timeline---covid-19. Accessed on 10 May 2020., Archived: WHO timeline-covid-19), January 2020, to October 2020. Findings indicate that there is a steady increase in the number of publications as well as the number of scientific collaborations over time. At a cross-country level, results suggest that the affiliated institutional sectors such as the Higher Education Sector (HES) and the Government Sector (GOV) contributed the most in terms of scientific output. On an international scale, the evolution of the scientific collaboration is imprinted and distributed as a chain of affiliations that linked nations together. Such chains are represented as clusters of countries, in which the scientific connections between different countries can be visualised. It can be reasoned that a significant amount of publications (20%) is affiliated with countries having "traditionally" major scientific impact on the field of Medicine. Supplementary Information: The online version contains supplementary material available at 10.1007/s11192-021-03952-9.

Absence of aprataxin gene mutations in a Greek cohort with sporadic early onset ataxia and normal GAA triplets in frataxin gene.

Phenotype of patients with the aprataxin gene mutation varies and according to previous studies, screening of aprataxin gene could be useful, once frataxin gene mutation is excluded in patients with normal GAA expansion in frataxin gene. In the present study, we sought to determine possible causative mutations in aprataxin gene (all exons and flanking intronic sequences) in 14 Greek patients with sporadic cerebellar ataxia all but one without GAA expansion in frataxin gene (1 patient was heterozygous). No detectable point mutation or deletion was found in the aprataxin gene of all the patients. Our results do not confirm the previous studies. This difference may be attributed to the different populations studied and possible different genetic background. It is still questionable whether the screening for aprataxin mutation in Greek patients' Friedreich ataxia phenotype is of clinical importance; larger, multicenter studies are necessary to clarify this issue.

High frequency of Friedreich's ataxia carriers in the Paphos district of Cyprus.

A cluster of Friedreich's ataxia patients has been previously investigated in two neighbouring villages of the Paphos district of Cyprus. Molecular genetic studies revealed that all patients had the most common mutation, a homozygous expansion of the GAA triplet repeat in the first intron of the frataxin gene. The present study is aimed at estimating the mutation carrier frequency in the broader area of Paphos. Overall, 1050 individuals originating from the Paphos district took part in the programme. Blood samples were collected for a period of 18 months, on a voluntary basis, after signing a consent form, and analysis of the GAA triplet repeat was performed. The frequency of mutation carriers in the broader area of the Paphos district, and excluding the two neighbouring cluster villages, is estimated to be high. We recommend that an organized prevention programme be implemented to cover the population from this region.

Composite description based on Salient Contours and Color information for CBIR tasks.

This paper introduces a novel image descriptor for content based image retrieval tasks that integrates contour and color information into a compact vector. Loosely inspired by the human visual system and its mechanisms in efficiently identifying visual saliency, operations are performed on a fixed lattice of discrete positions by a set of edge detecting kernels that calculate region derivatives at different scales and orientation. The description method utilizes a weighted edge histogram where bins are populated on the premise of whether the regions contain edges belonging to the salient contours, while the discriminative power is further enhanced by integrating regional quantized color information. The proposed technique is both efficient and adaptive to the specifics of each depiction, while it does not need any training data to adjust parameters. Experimental evaluation conducted on seven benchmarking datasets against 13 well known global descriptors along with SIFT, SURF implementations (both in VLAD and BOVW), highlight the effectiveness and efficiency of the proposed descriptor.

Management of gastrointestinal bezoars: an analysis of 23 cases.

Bezoars (BZs) represent the most common foreign bodies of the gastrointestinal tract. Clinical symptoms varying from no symptoms to acute abdominal obstruction. Our goal is to present our experience with a review of the literature. In this study, 23 patients with BZs of the upper gastrointestinal system (GIS) were treated in the surgical department of two generals hospitals in northwest Greece. The size of BZs, localization, predisposing factors, clinical symptoms, morbidity, and mortality were analyzed. Conservative treatment, endoscopic procedures, and surgical treatment were also parameters under consideration. Nineteen patients presenting with phytobezoars and four female patients presented with psychological disorders and mental retardation with trichobezoars. More than one half of them (57%) had previous gastric surgery. Surgical morbidity rate was 28%, whereas the endoscopic morbidity was 11%. Mortality was 4% and 0% for the surgical and endoscopic groups, respectively. The differences in morbidity and mortality rates between the two groups were not statistically significant. BZs are commonly found in the stomach and small intestine, especially in patients who underwent previous gastric surgery. Small bowel obstruction is the most common complication. When uncomplicated, endoscopic or surgical removal of the BZs can be performed easy and effectively.

Fundamental gating mechanism of nicotinic receptor channel revealed by mutation causing a congenital myasthenic syndrome.

We describe the genetic and kinetic defects in a congenital myasthenic syndrome due to the mutation epsilonA411P in the amphipathic helix of the acetylcholine receptor (AChR) epsilon subunit. Myasthenic patients from three unrelated families are either homozygous for epsilonA411P or are heterozygous and harbor a null mutation in the second epsilon allele, indicating that epsilonA411P is recessive. We expressed human AChRs containing wild-type or A411P epsilon subunits in 293HEK cells, recorded single channel currents at high bandwidth, and determined microscopic rate constants for individual channels using hidden Markov modeling. For individual wild-type and mutant channels, each rate constant distributes as a Gaussian function, but the spread in the distributions for channel opening and closing rate constants is greatly expanded by epsilonA411P. Prolines engineered into positions flanking residue 411 of the epsilon subunit greatly increase the range of activation kinetics similar to epsilonA411P, whereas prolines engineered into positions equivalent to epsilonA411 in beta and delta subunits are without effect. Thus, the amphipathic helix of the epsilon subunit stabilizes the channel, minimizing the number and range of kinetic modes accessible to individual AChRs. The findings suggest that analogous stabilizing structures are present in other ion channels, and possibly allosteric proteins in general, and that they evolved to maintain uniformity of activation episodes. The findings further suggest that the fundamental gating mechanism of the AChR channel can be explained by a corrugated energy landscape superimposed on a steeply sloped energy well.

Linkage of otosclerosis to a third locus (OTSC3) on human chromosome 6p21.3-22.3.

Clinical otosclerosis (OMIM 166800/605727) has a prevalence of 0.2-1% among white adults, making it the single most common cause of hearing impairment in this group. It is caused by abnormal bone homeostasis of the otic capsule with the consequent development of sclerotic foci that invade the stapedio-vestibular joint (oval window) interfering with free motion of the stapes. Impaired ossicular chain mobility results in a conductive hearing loss. We identified the first locus for otosclerosis (OTSC1) on chromosome 15 in 1998 and reported a second locus (OTSC2) on chromosome 7 last year. Here we present results of a genome wide linkage study on a large Cypriot family segregating otosclerosis. Results of this study exclude linkage to OTSC1 and OTSC2 and identify a third locus, OTSC3, on chromosome 6p. The defined OTSC3 interval covers the HLA region, consistent with reported associations between HLA-A/HLA-B antigens and otosclerosis.

Chromosome 17p-linked myasthenias stem from defects in the acetylcholine receptor epsilon-subunit gene.

OBJECTIVE: To identify and to characterize functionally the mutational basis of congenital myasthenic syndromes (CMS) linked to chromosome 17p. BACKGROUND: A total of 37 patients belonging to 13 CMS families, 9 of them consanguineous, were investigated. All patients were linked previously to the telomeric region of chromosome 17p. Two candidate genes in this region encode synaptobrevin 2, a presynaptic protein, and the epsilon-subunit of the acetylcholine receptor (AChR). Direct sequencing of the synaptobrevin 2 gene revealed no mutations. The authors thus searched for mutations in the epsilon-subunit gene of AChR. METHODS: Direct sequencing of the AChR epsilon-subunit, restriction analysis, allele-specific PCR, and expression studies in human embryonic kidney cells were performed. RESULTS: The authors identified two previously characterized and five novel epsilon-subunit gene mutations, all homozygous, in the 13 kinships. Two of the novel mutations are truncating (epsilon723delC and epsilon760ins8), one is a missense mutation in the signal peptide region (epsilonV-13D), one is a missense mutation in the N-terminal extracellular domain (epsilonT51P), and one is a splice donor site mutation in intron 10 (epsilonIVS10+2T-->G). Unaffected family members have no mutations or are heterozygous. Expression studies indicate that the four novel mutations in the coding region of the gene and the most likely transcript of the splice-site mutation, which skips exon 10, are low-expressor or null mutations. CONCLUSIONS: Chromosome 17p-linked congenital myasthenic syndromes are caused by low-expressor/null mutations in the AChR epsilon-subunit gene. Mutations in this gene are a common cause of CMS in eastern Mediterranean countries.

Medullary cystic kidney disease with hyperuricemia and gout in a large Cypriot family: no allelism with nephronophthisis type 1.

We describe a large Cypriot family with an interstitial type of nephropathy, inherited as an autosomal dominant trait that led to end stage renal failure between 51 to 78 years of age (mean 62.2 years). Twenty-three people are known to be affected, but several younger relatives with normal renal function may remain undiagnosed because of the absence of precise clinical and laboratory diagnostic criteria. This nephropathy is associated with medullary renal cysts, hypertension, hyperuricemia, and gout. Several relatives have typical medullary cystic disease (MCD), while in the others the findings are compatible with this diagnosis. Due to the similarity of clinical and pathologic findings, earlier reports had suggested that MCD may be allelic to autosomal recessive familial juvenile nephronophthisis, which was mapped recently to chromosome band 2q13. Linkage analysis of the present family with a closely linked marker excluded linkage to the above locus. Linkage was also excluded to the PKD1 locus of adult polycystic kidney disease type 1, and up to 5 cM on either side, on chromosome 16. We suggest that because of the element of hyperuricemia and gout found in this family, although with reduced penetrance, it may represent a variant of autosomal dominant MCD of the adult type. This variability may be the result of allelic or locus heterogeneity. Molecular genetic approaches including linkage analysis on appropriate families will certainly assist in classifying such related genetically heterogeneous disorders.

Distal hereditary motor neuronopathy of the Jerash type.

A novel form of autosomal recessive distal hereditary motor neuronopathy (distal HMN) is reported. The presence of pyramidal signs within the early stages of the disease with persistence of knee hyperreflexia form distinctive clinical features. We have mapped the HMN-J gene to chromosome 9p21.1-p12, within an estimated interval of 1.2-Mb.

Ursodeoxycholic acid (UDCA) for the treatment of amoxycillin-clavulanate potassium (Augmentin)-induced intra-hepatic cholestasis: report of two cases.

This report describes two patients who developed jaundice within two weeks of receiving an amoxycillin-clavulanate potassium combination. Causes of jaundice, other than drug administration, were excluded. The patients' jaundice and clinical symptoms did not respond to stopping the drug. Ursodeoxycholic acid (750 mg/day) led to a prompt and sustained improvement in their hyperbilirubinaemia and symptoms such as pruritus and fatigue. These cases suggest that ursodeoxycholic acid may be an effective treatment for drug-associated cholestasis.

Treatment of proctalgia fugax with botulinum A toxin.

Two recent studies described a temporal association between a high-amplitude and high-frequency myoelectrical activity of the anal sphincter and the occurrence of proctalgia, which suggest that paroxysmal hyperkinesis of the anus may cause proctalgia fugax. We describe a single case of proctalgia fugax responding to anal sphincter injection of Clostridium botulinum type A toxin. The presumed aetiology of proctalgia fugax is discussed and the possible mechanism of action of botulinum toxin (BTX) in this condition is outlined. Botulinum A toxin seems to be a promising treatment for patients with proctalgia fugax, and further trials appear to be worthwhile for this condition, which has been described as incurable.

Molecular genetic detection of Xp21 muscular dystrophy carriers in Cyprus.

Multiplex Polymerase Chain Reaction (PCR) for 18 different exons of the dystrophin gene was used to characterize the mutations in 29 Cypriot families with Duchenne or Becker Muscular Dystrophy. Deletions were detected in 21 out of 28 families from which DNA was available for an affected patient (75%). Quantitative Multiplex PCR further enabled the identification of a duplication in one of our families (3.6%). Quantitative Multiplex PCR also enabled carrier diagnosis in families where a deletion or a duplication was detectable in an affected patient. Out of 69 at-risk females examined in these families, 20 were shown by Quantitative Multiplex PCR to be carriers, including three obligatory carriers. In the remaining six families with a surviving patient, carrier diagnosis was based on haplotype analysis using microsatellite polymorphisms from the 5'- and 3'-ends of the dystrophin gene. Haplotype analysis was informative in three of the above families (10.7%). Thus, deletions or duplications were detected in 78.6% of our families with a surviving patient, while carrier diagnosis was possible in 89.3% of these families. In the single family without a surviving patient, Quantitative Multiplex PCR indicated the absence of a deletion or duplication in the mother, while haplotype analysis could not be carried out in the absence of an affected patient. The high rate of new mutations in the dystrophin gene of which only about 80% are directly detectable by Quantitative Multiplex PCR, and the difficulty of haplotype analysis in some of our families, restricts the usefulness of these techniques to about 90% of our families.

The role of somatostatin analogues in complete antiandrogen treatment in patients with prostatic carcinoma.

Somatostatin analogues (SMS-A) have been found to inhibit the growth of experimental tumors, as of prostate cancer, via several mechanisms as antihormonal and direct antimitogenic actions. It was demonstrated also that several SMS-A induce greater prostatic tumor regression with more pronounced histological changes if combined with LHRH analogues or in association with complete androgen blockade (CAB). In a phase II clinical trial we administered, in addition to CAB, SMS-A octreotide in 14 patients with stage D2 (group B) prostate cancer-8 previously hormonally treated (PHT) and 6 without any previous hormone treatment (NPHT); 4 other patients, 3 NPHT and one PHT, were treated with CAB only (group A). Antiandrogen and antitumoral activity followed assaying a) plasma testosterone b) prostatic specific antigen (PSA) c) prostatic acid phosphatase (PAP) levels and d) objective (o) and subjective (s) clinical improvement according to WHO criteria. Somatostatin activity was evaluated assaying Insulin like Growth Factor-1 (IGF-1) and Epidermal Growth Factor (EGF). In group B we observed 3 responses, with the best quality of response (oPR/sCR) among the 6 NPHT-patients (50%) and 3 responses among the PHT-patients (37,5%), two of them with an incomplete PHT. In group A, 2 out of 3 NPHT-patients had a response (oPR/sPR). Among group B patients we observed long symptom-free survival, when they responded (17 months), in comparison to group A patients (12 months), but almost the same total duration of survival in the two groups, 18.5 and 18 months, respectively. EGF and IGF-1 serum levels showed a distinct drop parallel to the decrease of PSA serum levels, among the patients with response vs. nonrespondent patients of group B during the treatment. Although our results showed that octreotide in small doses, in addition to CAB, having mild toxicity, enhance number, quality and perhaps the duration of symptom-free responses in patients with stage 2 prostate cancer, the therapeutic efficacy of this combined treatment remains to be ascertained in wider and better randomized clinical trials.

Second-line chemotherapy with cisplatin-ifosfamide in patients with ovarian cancer previously treated with carboplatin-cyclophosphamide.

In an effort to use antineoplastic drug combinations which are active in platinum resistant ovarian cancer or which can induce a second response after a platinum first-line treatment, we conducted a study on 30 ovarian cancer patients previously treated with carboplatin plus cyclophosphamide who were given ifosfamide 5 g/m2 i.v. divided over days 1 to 3 plus mesma combined with cisplatin 100 mg/m2 i.v. divided over days 1 to 3 every 4 weeks as second-line treatment. Eight patients had never entered remission with first-line chemotherapy while 22 patients had tumor recurrence within 6 to 18 months after the end of chemotherapy and their tumors were considered potentially platinum sensitive. Responding patients received 6 courses while palliative treatment for nonresponders was provided. Of the 22 patients with tumor recurrence, 8 patients responded with one partial response (PR) and 7 complete clinical responses (CCR). Two out of the 8 patients with platinum resistant disease demonstrated short lasting PR. Seven patients with CCR underwent second-look operation and in two a pathological CR was documented. Median time to progression was 6 mo (4-12). The median overall survival was 12 mo (4-20). Myelotoxicity despite G-CSF administration was significant with grade 4 leukopenia in 40% and grade 3 thrombocytopenia in 20% of patients. Central nervous system (CNS) toxicity was significant with 30% somnolence, 20% disorientation and an episode of grand-mal epilepsy ascribed to ifosfamide. With a 33% response rate the combination is as effective as new agents employed in relapsed ovarian cancer. Platinum-refractory disease may respond to a lesser degree. The most important determinant of response was the progression-free interval from first-line chemotherapy. Whether patients recurring after carboplatin plus cyclophosphamide have a greater chance to respond to cisplatin plus ifosfamide or vice-versa cannot be supported by the current data and therefore randomized studies should be performed to this end.