The role of human demographic history in determining the distribution and frequency of transferase-deficient galactosaemia mutations.

Classical or transferase-deficient galactosaemia is an inherited metabolic disorder caused by mutation in the human Galactose-1-phosphate uridyl transferase (GALT) gene. Of some 170 causative mutations reported, fewer than 10% are observed in more than one geographic region or ethnic group. To better understand the population history of the common GALT mutations, we have established a haplotyping system for the GALT locus incorporating eight single nucleotide polymorphisms and three short tandem repeat markers. We analysed haplotypes associated with the three most frequent GALT gene mutations, Q188R, K285N and Duarte-2 (D2), and estimated their age. Haplotype diversity, in conjunction with measures of genetic diversity and of linkage disequilibrium, indicated that Q188R and K285N are European mutations. The Q188R mutation arose in central Europe within the last 20 000 years, with its observed east-west cline of increasing relative allele frequency possibly being due to population expansion during the re-colonization of Europe by Homo sapiens in the Mesolithic age. K285N was found to be a younger mutation that originated in Eastern Europe and is probably more geographically restricted as it arose after all major European population expansions. The D2 variant was found to be an ancient mutation that originated before the expansion of Homo sapiens out of Africa.

The Human Variome Project country node of Argentina in the first two years of activity: past, present and future / El nodo Argentino del Proyecto Varioma Humano en los primeros dos años de actividad: pasado, presente y futuro

The Human Variome Project (HVP) is an international effort aiming systematically to collect and share information on all human genetic variants. It has been working for years in collaboration with local scientific societies by establishing systems to collect every genetic variant reported in a country and to store these variants within a database repository: LOVD (Argentinian chapter: ar.lovd.org). Formally established in 2017 in the Argentinian Node, up to June 2019 we collected more than 25,000 genetic variants deposited by 17 different laboratories. Nowadays the HVP country nodes represent more than 30 countries. In Latin America there are four country nodes: Argentina, Brazil, Mexico and Venezuela; the first two interacted recently launching the LatinGen database. In the present work we want to share our experience in applying the HVP project focusing on its organization, rules and nomenclature to reach the goal of sharing genetic variants and depositing them in the Leiden Open Variation Database. Contributing laboratories are seeking to share variant data to gain access all over the country. It is one of our goals to stimulate the highest quality by organizing courses, applying current nomenclature rules, sponsoring lectures in national congresses, distributing newsletter to serve the Argentinian genomics community and to stimulate the interaction among Latin America countries.

El Proyecto Varioma Humano (HVP) es un esfuerzo internacional que tiene como objetivo recopilar y compartir sistemáticamente información sobre todas las variantes genéticas humanas. Hemos estado trabajando durante tres años en colaboración con sociedades científicas locales, mediante el establecimiento de sistemas para recolectar todas las variantes genéticas reportadas en el país y almacenarlas dentro de la base de datos LOVD (capítulo argentino: ar.lovd.org). En el año 2017 fue establecido formalmente el Nodo Argentino del HVP, habiéndose recolectado más de 25.000 variantes genéticas depositadas por 17 laboratorios diferentes hasta junio de 2019. Hoy en día existen al menos 30 nodos del HVP, correspondientes a diferentes países. En América Latina hay cuatro nodos: Argentina, Brasil, México y Venezuela; Los dos primeros interactuaron recientemente lanzando la base de datos LatinGen. En el presente trabajo queremos compartir nuestra experiencia en la aplicación del proyecto HVP centrándonos en su organización, reglas y nomenclatura para alcanzar el objetivo de compartir variantes genéticas y depositarlas en la base de datos de variaciones abiertas de Leiden (LOVD). Es uno de nuestros objetivos estimular la más alta calidad mediante la organización de cursos, aplicación de las reglas de nomenclatura actuales, patrocinio de conferencias en congresos nacionales, distribución de boletines informativos para la comunidad de genómica argentina, y estimulación de la interacción entre los países de América Latina.

Insulin growth factor-binding protein 2 is a candidate biomarker for PTEN status and PI3K/Akt pathway activation in glioblastoma and prostate cancer.

PTEN is an important tumor-suppressor gene associated with many cancers. Through expression profiling of glioblastoma tissue samples and prostate cancer xenografts, we identified a molecular signature for loss of the PTEN tumor suppressor in glioblastoma and prostate tumors. The PTEN signature consists of a minimum of nine genes, several of which are involved in various pathways already implicated in tumor formation. Among these signature genes, the most significant was an increase in insulin growth factor-binding protein 2 (IGFBP-2) mRNA. Up-regulation of IGFBP-2 was confirmed at the protein level by Western blot analysis and validated in samples not included in the microarray analysis. The link between IGFBP-2 and PTEN was of particular interest because elevated serum IGFBP-2 levels have been reported in patients with prostate and brain tumors. To further investigate this link, we determined that IGFBP-2 expression is negatively regulated by PTEN and positively regulated by phosphatidylinositol 3-kinase (PI3K) and Akt activation. In addition, Akt-driven transformation is impaired in IGFBP2(-/-) mouse embryo fibroblasts, implicating a functional role for IGFBP-2 in PTEN signaling. Collectively, these studies establish that PTEN and IGFBP-2 expression are inversely correlated in human brain and prostate cancers and implicate serum IGFBP-2 levels as a potential serum biomarker of PTEN status and PI3K Akt pathway activation in cancer patients.