Identification and characterization of HMBS gene mutations in Spanish patients with acute intermittent porphyria.

Acute intermittent porphyria (AIP), the most common acute hepatic porphyria, is an autosomal dominant disorder with low penetrance that results from a partial deficiency of hydroxymethylbilane synthase (HMBS), the third enzyme in the heme biosynthetic pathway. The disease is clinically characterized by acute neurovisceral attacks that are precipitated by several factors including certain drugs, steroid hormones, alcohol and fasting. Early diagnosis and counselling are essential to prevent attacks, being mutation analysis the most reliable method to identify asymptomatic carriers in AIP families. In this study we have investigated the molecular defect in 15 unrelated Spanish AIP patients. Mutation analysis of the HMBS gene revealed a total of fourteen mutations including six novel ones, two of them were on the same allele in one patient. The novel mutations were three missense (R26L, R173G and D178H), two frameshift (c.749_765dup and c.874insC) and one intronic deletion (IVS12+3_+11delAGGGCCTGT). RT-PCR and sequencing demonstrated that the intronic mutation caused abnormal splicing and exon 12 skipping. Prokaryotic expression of the novel missense mutations showed that only D178H had significant residual activity. These findings will facilitate the accurate identification of presymptomatic AIP carriers in these families and they further emphasize the molecular heterogeneity of AIP in Spain.

Nuevas metodologías docentes aplicadas al estudio de la fisiología y la anatomía: estudio comparativo con el método tradicional / Novel methodologies applied to Physiology and Anatomy teaching: comparison with traditional teaching

Introducción. El estudio integrado de la fisiología y la anatomía constituye una asignatura troncal dentro de las titulaciones de ciencias de la salud. La adaptación de la enseñanza de esta materia al estándar de Bolonia supone un reto metodológico dada su complejidad curricular y sus perfiles competenciales específicos. Objetivos. Evaluar experimentalmente una metodología mixta en la enseñanza de la fisiología y anatomía tanto en los resultados del aprendizaje como en la adquisición de competencias de los alumnos, así como desarrollar un baremo de medición del aprendizaje. Sujetos y métodos. Se comparan los resultados del aprendizaje en la diplomatura de podología de la Universidad Europea de Madrid entre un grupo control(metodología clásica: lección magistral) y uno experimental(metodología mixta: problemas, casos clínicos, trabajo en grupo y lección magistral). Resultados. Se muestra que con una aproximación mixta los alumnos adquieren habilidades y competencias a lo largo del curso, estabilizándose el aprendizaje lo suficiente y equilibrándose las diferencias individuales, en contraste con el grupo control. Esta homogeneización del aprendizaje se manifiesta como una menor variabilidad de la nota media de los exámenes en el grupo experimental, e indica el soporte que supone el método mixto para el aprendizaje de los alumnos con mayores dificultades. Se detecta una fuerte regresión lineal entre la asistencia a clase y los resultados del aprendizaje, y se confirma la importancia de la supervisión del proceso de aprendizaje por parte del profesor. Conclusión. El método mixto de enseñanza de la fisiología y la anatomía permite a los alumnos adquirir habilidades y competencias a lo largo del curso, equilibrando las diferencias como parte del proceso de aprendizaje (AU)

Introduction. The integrated study of Anatomy and Physiologyis mandatory in Health Sciences careers. The adaptation of these topics to the Bolonia paradigm in Europe is a methodological challenge due to the curricular complexity and specific competencies profiles involved. Aims. To evaluate a mixed methodology in the Physiology and Anatomy teaching aimed to measure knowledge and competencies. We also propose an evaluation scale to score learning. Subjects and methods. Data were gathered from a control group (classical methodology: lectures) which was compared with an experimental group (mixed methodology: problem-based learning(PBL), clinical cases, team working and lectures) in the Podiatric School at the Universidad Europea de Madrid. Knowledge was measured with multiple choice exams and PBL, clinical cases and team working evaluation. Results. We show that the students gain knowledge and competences during the academic course using a new mixed methodology for teaching. In contrast to the control group, knowledge in the experimental group stabilizes over the academic course making individual differences between the students insignificant. This homogenization becomes evident as a lower variability of the average scores of the experimental group and gives support to the value of a mixed methodology for students with more difficulties. There is a strong linear regression between class attendance and exam scores, confirming the importance of face-to-face supervision for learning. Conclusions. A mixed methodology for Physiology and Anatomy teaching allows the students to acquire abilities and competencies, also helping to equilibrate individual differences during the learning process (AU)

Molecular heterogeneity of familial porphyria cutanea tarda in Spain: characterization of 10 novel mutations in the UROD gene.

BACKGROUND: Porphyria cutanea tarda (PCT) results from decreased hepatic uroporphyrinogen decarboxylase (UROD) activity. In the majority of patients, the disease is sporadic (S-PCT or type I) and the enzyme deficiency is limited to the liver. Familial PCT (F-PCT or type II) is observed in 20-30% of patients in whom mutations on one allele of the UROD gene reduce UROD activity by approximately 50% in all tissues. Another variant of PCT (type III) is characterized by family history of the disease although it is biochemically indistinguishable from S-PCT. OBJECTIVES: To investigate the molecular basis of PCT in Spain and to compare enzymatic and molecular analysis for the identification of patients with F-PCT. METHODS: Erythrocyte UROD activity measurement and mutation analysis of the UROD gene were carried out in a cohort of 61 unrelated Spanish patients with PCT and 50 control individuals. Furthermore, each novel missense mutation identified was characterized by prokaryotic expression studies. RESULTS: Of these 61 patients, 40 (66%) were classified as having S-PCT, 16 (26%) as having F-PCT and five (8%) as having type III PCT. Discordant results between enzymatic and molecular analysis were observed in two patients with F-PCT. In total, 14 distinct mutations were found, including 10 novel mutations: five missense, one nonsense, three deletions and an insertion. Prokaryotic expression of the novel missense mutations demonstrated that each results in decreased enzyme activity or stability. CONCLUSIONS: These results confirm the high degree of molecular heterogeneity of F-PCT in Spain and emphasize the usefulness of molecular genetic analysis to distinguish between F-PCT and S-PCT.