Lack of association of polymorphisms in six candidate genes in colombian adhd patients.

BACKGROUND: Attention Deficit and Hyperactivity Disorder (ADHD) is a common childhood neuropsychiatric condition. The disorder has a multifactorial background, with heritability estimates of around 76%, suggesting an important role of genetic factors. Candidate genes include those related to dopaminergic (e.g. DRD4, DRD5, SLC6A3 and DBH)and serotoninergic (e.g.HTR1B and SLC6A4) pathways. PURPOSE: To explore the association of common polymorphisms in six genes (DRD4, DRD5, SLC6A3, DBH, HTR1B and SLC6A4) and the susceptibility to ADHD in a Colombian sample population. METHODS: trios and 152 healthy controls were recruited. Genotyping of the six polymorphisms was performed using described PCR-based protocols. A TDT analysis was used to test if there was preferential allelic transmission for any of the six polymorphisms. Additionally, a case-control analysis was performed to test for association of the serotoninergic (HTR1B and SLC6A4) polymorphisms with ADHD. RESULTS: Through the TDT analysis there was no preferential allelic transmission for any of the studied variants. Case-control analysis did not show association. CONCLUSION: This is the first study in Latin America to describe six polymorphisms in a group of patients with ADHD. There was no evidence of association for any of the studied polymorphic variants in this Colombian ADHD sample. Further research, with larger sample sizes and study of endophenotypes, is needed in this population to confirm and extend the results.

Evidence of association between SNAP25 gene and attention deficit hyperactivity disorder in a Latin American sample.

Attention deficit hyperactivity disorder (ADHD) is one of the most highly heritable behavioral disorders in childhood, with heritability estimates between 60 and 90 %. Family, twin and adoption studies have indicated a strong genetic component in the susceptibility to ADHD. The synaptosomal-associated protein of molecular weight 25 kDa (SNAP25) is a plasma membrane protein known to be involved in synaptic and neural plasticity. Animal model studies have shown that SNAP25 gene is responsible for hyperkinetic behavior in the coloboma mouse. In recent studies, several authors reported an association between SNAP25 and ADHD. In this study, we used a case-control approach to analyze the possible association of two polymorphisms of SNAP25 for possible association with ADHD in a sample of 73 cases and 152 controls in a Colombian children population. Polymorphisms are located in 3' untranslated region of SNAP25, positions T1065G and T1069C. We found a significant association with the GT haplotype (rs3746554|rs1051312) of SNAP25 (p = 0.001). Evidence of association was also found for the G/G genotype of rs3746554 (p = 0.002) and C/C genotype of rs1051312 (p = 0.009). This is the first study in a Latin American population. Similar to other studies, we found evidence of the association of SNAP25 and ADHD.

Prostaglandin transporter mutations cause pachydermoperiostosis with myelofibrosis.

Pachydermoperiostosis, or primary hypertrophic osteoarthropathy (PHO), is an inherited multisystem disorder, whose features closely mimic the reactive osteoarthropathy that commonly accompanies neoplastic and inflammatory pathologies. We previously described deficiency of the prostaglandin-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (HPGD) as a cause of this condition, implicating elevated circulating prostaglandin E(2) (PGE(2)) as causative of PHO, and perhaps also as the principal mediator of secondary HO. However, PHO is genetically heterogeneous. Here, we use whole-exome sequencing to identify recessive mutations of the prostaglandin transporter SLCO2A1, in individuals lacking HPGD mutations. We performed exome sequencing of four probands with severe PHO, followed by conventional mutation analysis of SLCO2A1 in nine others. Biallelic SLCO2A1 mutations were identified in 12 of the 13 families. Affected individuals had elevated urinary PGE(2), but unlike HPGD-deficient patients, also excreted considerable quantities of the PGE(2) metabolite, PGE-M. Clinical differences between the two groups were also identified, notably that SLCO2A1-deficient individuals have a high frequency of severe anemia due to myelofibrosis. These findings reinforce the key role of systemic or local prostaglandin excess as the stimulus to HO. They also suggest that the induction or maintenance of hematopoietic stem cells by prostaglandin may depend upon transporter activity.

Por que hacer tamizaje para hipotiroidismo congénito? / Why do we do screening for congenital hypothyroidism?

Con la implementación del sistema de Seguridad Social en Salud en el año 1993, mediante el desarrollo de la Ley 100, el modelo de prestación de servicios de salud en el pais sufrió una transformación global, de un modelo desarticulado y de baja cobertura se pasa a un modelo de aseguramiento universal y mayor cobertura, con protección integral y en donde la familia, o grupo familiar, esta protegido frente a las más importantes contingencias en salud. De otra parte beneficios en cuanto a calidad, confiabilidad y oportunidad, hacen parte de este nuevo modelo en donde se espera que los usuarios mejores su calidad de vida. La necesidad de fortalecer acciones de prevención ha sido uno de los retos que el actual Sistema General de Seguridad Social en Salud plantea a los planificadores de salud, es asi que el imperativo de desarrollar un modelo basado en el costo, la eficiencia, la calidad y la generación de salud requiere la definición de políticas de salud pública que obliguen a la realización de acciones concertadas y efectivas entre los diferentes actores del Sistema, Aseguradores, Proveedores y Usuarios, para asi mismo ofrecer servicios enfocados a las necesidades epidemiológicas de la población colombiana. Dentro de este desarrollo de la Seguridad Social en Salud la definición de una política relacionada con la prevención de enfermedades de alto impacto económico y social es una prioridad y es así que la identificación temprana del hipotiroidismo congénito es un avance significativo si se quiere mejorar la calidad de vida de la población.