Underlying Mechanisms Involved in Gambling Disorder Severity: A Pathway Analysis Considering Genetic, Psychosocial, and Clinical Variables.

Gambling Disorder (GD) has a complex etiology that involves biological and environmental aspects. From a genetic perspective, neurotrophic factors (NTFs) polymorphisms have been associated with the risk of developing GD. The aim of this study was to assess the underlying mechanisms implicated in GD severity by considering the direct and mediational relationship between different variables including genetic, psychological, socio-demographic, and clinical factors. To do so, we used genetic variants that were significantly associated with an increased risk for GD and evaluated its relationship with GD severity through pathway analysis. We found that the interaction between these genetic variants and other different biopsychological features predicted a higher severity of GD. On the one hand, the presence of haplotype block 2, interrelated with haplotype block 3, was linked to a more dysfunctional personality profile and a worse psychopathological state, which, in turn, had a direct link with GD severity. On the other hand, having rs3763614 predicted higher general psychopathology and therefore, higher GD severity. The current study described the presence of complex interactions between biopsychosocial variables previously associated with the etiopathogenesis and severity of GD, while also supporting the involvement of genetic variants from the NTF family.

Los aspectos éticos en la redacción del manuscrito científico / Ethical aspects in writing a scientific manuscript

La publicación de un manuscrito científico constituye uno de los puntos clave de la producción científica, especialmente en el ámbito biomédico, donde los resultados de nuestras investigaciones pueden ser trasladados rápidamente a la práctica clínica asistencial con el objeto de mejorar la salud y el bienestar de la sociedad. Toda investigación biomédica debe cumplir con unos estándares metodológicos, éticos y legales, para que el conocimiento generado sea considerado válido. El manuscrito deberá reflejar claramente el cumplimiento de estos estándares, y será exigible por los propios editores de las revistas biomédicas. Existen diversas guías y orientaciones para los autores de los manuscritos biomédicos. No obstante, estos documentos inciden principalmente en aspectos relacionados con la calidad científica, obviando generalmente los aspectos éticos. El presente trabajo ofrece indicaciones y argumentos a los potenciales autores para redactar el apartado correspondiente a los aspectos éticos, que se concretan principalmente en el respeto a los códigos bioéticos vigentes y la aprobación del comité de ética de la investigación, el procedimiento de consentimiento informado y, finalmente, las medidas de protección de la confidencialidad. (AU)

Publication of a scientific manuscript is one of the key points of scientific production, especially in the biomedical field, where the results of our research can be quickly transferred to clinical care practice in order to improve the health and well-being of the population. All biomedical research must comply with methodological, ethical and legal standards, so that the knowledge generated is considered valid. The manuscript must clearly exhibit compliance with these standards, which will be enforceable by the editors of the biomedical journals themselves. There are various guides and guidelines for the authors of biomedical manuscripts; however, these documents mainly affect aspects related to scientific quality, generally ignoring ethical aspects. This paper offers indications and arguments for potential authors to write the section on ethical aspects, which are mainly specified as related to current bioethical codes and approval by the research ethics committee, the informed consent procedure and, finally, confidentiality protection measures. (AU)

The role of neurotrophin genes involved in the vulnerability to gambling disorder.

Evidence about the involvement of genetic factors in the development of gambling disorder (GD) has been assessed. Among studies assessing heritability and biological vulnerability for GD, neurotrophin (NTF) genes have emerged as promising targets, since a growing literature showed a possible link between NTF and addiction-related disorders. Thus, we aimed to explore the role of NTF genes and GD with the hypothesis that some NTF gene polymorphisms could constitute biological risk factors. The sample included 166 patients with GD and 191 healthy controls. 36 single nucleotide polymorphisms (SNPs) from NTFs (NGF, NGFR, NTRK1, BDNF, NTRK2, NTF3, NTRK3, NTF4, CNTF and CNTFR) were selected and genotyped. Linkage disequilibrium (LD) and haplotype constructions were analyzed, in relationship with the presence of GD. Finally, regulatory elements overlapping the identified SNPs variants associated with GD were searched. The between groups comparisons of allele frequencies indicated that 6 SNPs were potentially associated with GD. Single and multiple-marker analyses showed a strong association between both NTF3 and NTRK2 genes, and GD. The present study supports the involvement of the NTF family in the aetiopathogenesis of GD. An altered cross-regulation of different NTF members signalling pathways might be considered as a biological vulnerability factor for GD.

Investigación biomédica con muestras biológicas de origen humano: un nuevo reto para la Bioética y los Comités Éticos de Investigación Clínica / Biomedical research with human biological samples: A new challenge for Bioethics and for the Clinical Research Ethics Committees

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Dopamine DRD2/ANKK1 Taq1A and DAT1 VNTR polymorphisms are associated with a cognitive flexibility profile in pathological gamblers.

Like drug addiction, pathological gambling (PG) has been associated with impairments in executive functions and alterations in dopaminergic functioning; however, the role of dopamine (DA) in the executive profile of PG remains unclear. The aim of this study was to identify whether the DRD2/ANKK1 Taq1A-rs1800497 and the DAT1-40 bp VNTR polymorphisms are associated with cognitive flexibility (measured by Wisconsin Card Sorting Test (WCST) and Trail Making Test (TMT)) and inhibition response (measured by Stroop Color and Word Test (SCWT)), in a clinical sample of 69 PG patients. Our results showed an association between DA functioning and cognitive flexibility performance. The Taq1A A1+ (A1A2/A1A1) genotype was associated with poorer TMT performance (p<0.05), while DAT1 9-repeat homozygotes displayed better WCST performance (p<0.05) than either 10-repeat homozygotes or heterozygotes. We did not find any association between the DRD2 or DAT1 polymorphisms and the inhibition response. These results suggested that pathological gamblers with genetic predispositions toward lower availability of DA and D2 receptor density are at a higher risk of cognitive flexibility difficulties. Future studies should aim to shed more light on the genetic mechanisms underlying the executive profile in PG.

HUMTH01, HUMVWA31A, HUMCSF1PO and HUMTPOX polymorphisms in Amerindian populations living in the Beni department of Bolivia.

This report presents allele frequency and absolute genotype data of the short tandem repeat (STR) loci HUMTH01, HUMVWA31A, HUMCSF1PO and HUMTPOX for three autochthonous Amerindian populations living in the Beni Department of Bolivia. These related groups are the Quechua, Aymara and Beni populations all living in specific although sometimes overlapping areas that extend from the Andean habitat to the lowland Llanos de Moxos savannah passing through the Piedmont hills. The usefulness of these loci for paternity and identification testing was also examined. The present work completes previous genetic studies performed by the authors in these populations including mtDNA haplogroups (Bert et al., Hum Biol, 73:1-16, 2001) and HVRI data (Bert et al., Ann Hum Biol 31:9-28, 2004; Corella et al., Ann Hum Biol 34:34-35, 2007).

Analyzing the genetic structure of the Tepehua in relation to other neighbouring Mesoamerican populations. A study based on allele frequencies of STR markers.

We report data on the genetic variation of the Tepehua population based on 15 autosomal microsatellites. The Tepehua, whose language belongs to the Totonac family, are settled throughout the Sierra Madre Oriental in Mexico and constitute a group in demographic decline. The results suggest that the Tepehua population remained isolated throughout a large part of its history. Phylogenetic analyses performed with other indigenous and admixed populations of Mesoamerica allow us to address their biological history. The results suggest a genetic affinity between the Tepehua and the Huastecos due to their previous shared history, and a certain degree of differentiation from the Otomões groups and the Choles (who are of Mayan origin). A clear genetic differentiation is also apparent between native and admixed populations within the greater region of Mesoamerica. It is currently accepted that the genetic composition of the American populations fits a trihybrid model of admixture. The genetic structure based on comparison of 34 populations throughout the continent (9 indigenous and 23 admixed) using hierarchical cluster analysis with an explained variance of 61.17% suggests the existence of four large groups distinguished according to the degree of admixture between Amerindians, Europeans, and Africans.

Mitochondrial DNA diversity of the Amerindian populations living in the Andean Piedmont of Bolivia: Chimane, Moseten, Aymara and Quechua.

BACKGROUND: Chimane, Moseten Aymara and Quechua are Amerindian populations living in the Bolivian Piedmont, a characteristic ecoregion between the eastern slope of the Andean mountains and the Amazonian Llanos de Moxos. In both neighbouring areas, dense and complex societies have developed over the centuries. The Piedmont area is especially interesting from a human peopling perspective since there is no clear evidence regarding the genetic influence and peculiarities of these populations. This land has been used extensively as a territory of economic and cultural exchange between the Andes and Amazonia, however Chimane and Moseten populations have been sufficiently isolated from their neighbour groups to be recognized as distinct populations. Genetic information suggests that evolutionary processes, such as genetic drift, natural selection and genetic admixture have formed the history of the Piedmont populations. AIM: The objective of this study is to characterize the genetic diversity of the Piedmont populations, analysing the sequence variability of the HVR-I control region in the mitochondrial DNA (mtDNA). Haplogroup mtDNA data available from the whole of Central and South America were utilized to determine the relationship of the Piedmont populations with other Amerindian populations. SUBJECT AND METHODS: Hair pulls were obtained in situ, and DNA from non-related individuals was extracted using a standard Chelex 100 method. A 401 bp DNA fragment of HVR-I region was amplified using standard procedures. Two independent 401 and 328 bp DNA fragments were sequenced separately for each sample. The sequence analyses included mismatch distribution and mean pairwise differences, median network analyses, AMOVA and principal component analyses. The genetic diversity of DNA sequences was measured and compared with other South Amerindian populations. RESULTS: The genetic diversity of 401 nucleotide mtDNA sequences, in the hypervariable Control Region, from positions 16 000-16 400, was characterized in a sample of 46 Amerindians living in the Piedmont area in the Beni Department of Bolivia. The results obtained indicate that the genetic diversity in the area is higher than that observed in other American groups living in much larger areas and despite the reduced size of the studied area the human groups analysed show high levels of inter-group variability. In addition, results show that Amerindian populations living in the Piedmont are genetically more related to those in the Andean than in the Amazonian populations.

D1S80 polymorphism, including a new variant, in a population sample from Barcelona (Spain) using polymerase chain reaction.

Allele and genotype frequencies for the D1S80 (MCT118) locus have been determined in a population sample from Barcelona (Spain) using the polymerase chain reaction (PCR) amplification and nonradioactive detection. In a total of 216 unrelated individuals, 24 alleles (23 common and 1 rare variant) and 67 genotypes (64 common and 3 variants) were observed. The 216 individuals came from 162 blood samples taken for paternity studies, 16 bloodstains from forensic cases, and 38 root hairs from normal individuals. The D1S80 locus demonstrated a heterozygosity of 0.7916, and a power of discrimination of 0.9731. The distribution of genotypes is in agreement with expected values according to the Hardy-Weinberg equilibrium. Additionally, the population from Barcelona differs, significantly, from the Finnish population and also, but with lower differences, from a U.S.A. Caucasian population. © 1993 Wiley-Liss, Inc.