Genes asociados a displasias esqueléticas. Diagnóstico e implicación en el asesoramiento genético (1998-2012)

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 22-01-2016Esta tesis tiene embargado el acceso al texto completo hasta el 22-07-2017Instituto de Investigación Sanitaria. Fundación Jiménez DíazLas displasias esqueléticas son un amplio campo de estudio que requiere unidades disciplinares de las distintas especialidades involucradas en su desarrollo. Esta tesis, basada en un trabajo principalmente asistencial, ha intentado dar respuesta al mayor número de demandas solicitantes de displasias esqueléticas recogidas en dos periodos: desde su inicio a 2006, y tras la concesión de un proyecto específico, de 2007 a 2012. En ese intento se han puesto a punto nuevos genes y nuevas herramientas diagnósticas que han permitido caracterizar mutaciones familiares que han facilitado la realización de un asesoramiento genético individual, familiar y reproductivo, fin último del estudio genético. Ante alteraciones ecográficas el gen FGFR3 juega un papel importante en el diagnóstico, con una sensibilidad de hasta el 60% en los fetos con hipoplasia torácica y micromelia. El estudio de las craneosinostosis aisladas sindrómicas requiere de un primer cribado del exón 7 del gen FGFR3 así como de los exones 7 y 8 del gen FGFR2, seguido de la aplicación de la secuenciación masiva en una segunda aproximación diagnóstica. El estudio de la talla baja disarmónica requiere de la secuenciación seriada del gen FGFR3, gen SHOX y gen COMP. Existen otras tallas bajas disarmónicas con fenotipos característicos reconocibles que dirigen el estudio molecular de forma concreta (genes RMRP y COMP). La puesta a punto del gen SLC26A2 se realizó ante un resultado molecular no concluyente en una pareja y su hija afecta. El estudio de la talla baja idiopática se centra en las alteraciones en el gen SHOX. La selección de los pacientes y la aplicación de una escala clínica que cribe los pacientes a estudio es necesaria para optimizar recursos y expectativas diagnósticas. Una buena exploración y recogida de datos, así como dar una explicación detallada de las alteraciones encontradas, es un requisito imprescindible para orientar el estudio molecular y, ante un primer resultado negativo, tener la información para poder proponer otros diagnósticos diferenciales. Esta premisa es independiente de la técnica molecular que se utilice: desde la robusta y conocida secuenciación de sanger hasta las nuevas herramientas diagnósticas de secuenciación masiva

Optimization of adsorptive removal of α-toluic acid by CaO2 nanoparticles using response surface methodology

The present work addresses the optimization of process parameters for adsorptive removal of α-toluic acid by calcium peroxide (CaO2) nanoparticles using response surface methodology (RSM). CaO2 nanoparticles were synthesized by chemical precipitation method and confirmed by Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analysis which shows the CaO2 nanoparticles size range of 5–15 nm. A series of batch adsorption experiments were performed using CaO2 nanoparticles to remove α-toluic acid from the aqueous solution. Further, an experimental based central composite design (CCD) was developed to study the interactive effect of CaO2 adsorbent dosage, initial concentration of α-toluic acid, and contact time on α-toluic acid removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was performed to determine the significance of the individual and the interactive effects of variables on the response. The model predicted response showed a good agreement with the experimental response, and the coefficient of determination, (R2) was 0.92. Among the variables, the interactive effect of adsorbent dosage and the initial α-toluic acid concentration was found to have more influence on the response than the contact time. Numerical optimization of process by RSM showed the optimal adsorbent dosage, initial concentration of α-toluic acid, and contact time as 0.03 g, 7.06 g/L, and 34 min respectively. The predicted removal efficiency was 99.50%. The experiments performed under these conditions showed α-toluic acid removal efficiency up to 98.05%, which confirmed the adequacy of the model prediction

Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589

Clinical and genetic characteristics of late-onset Huntington's disease

Background: The frequency of late-onset Huntington's disease (&gt;59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30–50 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of ≤35 or a UHDRS motor score of ≤5 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P &lt;.001). Overall motor and cognitive performance (P &lt;.001) were worse, however only disease motor progression was slower (coefficient, −0.58; SE 0.16; P &lt;.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P &lt;.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P &lt;.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients