Mapa epidemiológico transversal de las ataxias y paraparesias espásticas hereditarias en España / Epidemiology of ataxia and hereditary spastic paraplegia in Spain: a cross-sectional study

Introducción: Las ataxias (AT) y paraparesias espásticas hereditarias (PEH) son síndromes neu-rodegenerativos raros. Nos proponemos conocer la prevalencia de las AT y PEH en Espa˜na en2019.Pacientes y métodos: Estudio transversal, multicéntrico, descriptivo y retrospectivo de lospacientes con AT y PEH, desde marzo de 2018 a diciembre de 2019 en toda Espa˜na.Resultados: Se obtuvo información de 1933 pacientes procedentes de 11 Comunidades Autóno-mas, de 47 neurólogos o genetistas. Edad media: 53,64 a˜nos ± 20,51 desviación estándar (DE);938 varones (48,5%), 995 mujeres (51,5%). En 920 pacientes (47,6%) no se conoce el defectogenético. Por patologías, 1.371 pacientes (70,9%) diagnosticados de AT, 562 diagnosticados dePEH (29,1%). La prevalencia estimada de AT es 5,48/100.000 habitantes, y la de PEH es 2,24casos/100.000 habitantes. La AT dominante más frecuente es la SCA3. La AT recesiva más fre-cuente es la ataxia de Friedreich (FRDA). La PEH dominante más frecuente es la SPG4, y la PEHrecesiva más frecuente es la SPG7.Conclusiones: La prevalencia estimada de AT y PEH en nuestra serie es de 7,73 casos/100.000habitantes. Estas frecuencias son similares a las del resto del mundo. En el 47,6% no se haconseguido un diagnóstico genético. A pesar de las limitaciones, este estudio puede contribuira estimar los recursos, visibilizar estas enfermedades, detectar las mutaciones más frecuentespara hacer los screenings por comunidades, y favorecer los ensayos clínicos.(AU)

Introduction: Ataxia and hereditary spastic paraplegia are rare neurodegenerative syndromes.We aimed to determine the prevalence of these disorders in Spain in 2019.Patients and methods: We conducted a cross-sectional, multicentre, retrospective, descrip-tive study of patients with ataxia and hereditary spastic paraplegia in Spain between March2018 and December 2019. Results: We gathered data from a total of 1933 patients from 11 autonomous communities,provided by 47 neurologists or geneticists. Mean (SD) age in our sample was 53.64 (20.51)years; 938 patients were men (48.5%) and 995 were women (51.5%). The genetic defect wasunidentified in 920 patients (47.6%). A total of 1371 patients (70.9%) had ataxia and 562 (29.1%)had hereditary spastic paraplegia. Prevalence rates for ataxia and hereditary spastic paraplegiawere estimated at 5.48 and 2.24 cases per 100 000 population, respectively. The most frequenttype of dominant ataxia in our sample was SCA3, and the most frequent recessive ataxia wasFriedreich ataxia. The most frequent type of dominant hereditary spastic paraplegia in oursample was SPG4, and the most frequent recessive type was SPG7.Conclusions: In our sample, the estimated prevalence of ataxia and hereditary spastic para-plegia was 7.73 cases per 100 000 population. This rate is similar to those reported for othercountries. Genetic diagnosis was not available in 47.6% of cases. Despite these limitations, ourstudy provides useful data for estimating the necessary healthcare resources for these patients,raising awareness of these diseases, determining the most frequent causal mutations for localscreening programmes, and promoting the development of clinical trials.(AU)

Epidemiology of ataxia and hereditary spastic paraplegia in Spain: A cross-sectional study.

INTRODUCTION: Ataxia and hereditary spastic paraplegia are rare neurodegenerative syndromes. We aimed to determine the prevalence of these disorders in Spain in 2019. PATIENTS AND METHODS: We conducted a cross-sectional, multicentre, retrospective, descriptive study of patients with ataxia and hereditary spastic paraplegia in Spain between March 2018 and December 2019. RESULTS: We gathered data from a total of 1933 patients from 11 autonomous communities, provided by 47 neurologists or geneticists. Mean (SD) age in our sample was 53.64 (20.51) years; 938 patients were men (48.5%) and 995 were women (51.5%). The genetic defect was unidentified in 920 patients (47.6%). A total of 1371 patients (70.9%) had ataxia and 562 (29.1%) had hereditary spastic paraplegia. Prevalence rates for ataxia and hereditary spastic paraplegia were estimated at 5.48 and 2.24 cases per 100 000 population, respectively. The most frequent type of dominant ataxia in our sample was SCA3, and the most frequent recessive ataxia was Friedreich ataxia. The most frequent type of dominant hereditary spastic paraplegia in our sample was SPG4, and the most frequent recessive type was SPG7. CONCLUSIONS: In our sample, the estimated prevalence of ataxia and hereditary spastic paraplegia was 7.73 cases per 100 000 population. This rate is similar to those reported for other countries. Genetic diagnosis was not available in 47.6% of cases. Despite these limitations, our study provides useful data for estimating the necessary healthcare resources for these patients, raising awareness of these diseases, determining the most frequent causal mutations for local screening programmes, and promoting the development of clinical trials.

Epidemiology of ataxia and hereditary spastic paraplegia in Spain: a cross-sectional study. / Mapa epidemiológico transversal de las ataxias y paraparesias espásticas hereditarias en España.

INTRODUCTION: Ataxia and hereditary spastic paraplegia are rare neurodegenerative syndromes. We aimed to determine the prevalence of these disorders in Spain in 2019. PATIENTS AND METHODS: We conducted a cross-sectional, multicentre, retrospective, descriptive study of patients with ataxia and hereditary spastic paraplegia in Spain between March 2018 and December 2019. RESULTS: We gathered data from a total of 1.809 patients from 11 autonomous communities, provided by 47 neurologists or geneticists. Mean (SD) age in our sample was 53.64 (20.51) years; 920 patients were men (50.8%) and 889 were women (49.2%). The genetic defect was unidentified in 920 patients (47.6%). A total of 1371 patients (70.9%) had ataxia and 562 (29.1%) had hereditary spastic paraplegia. Prevalence rates for ataxia and hereditary spastic paraplegia were estimated at 5.48 and 2.24 cases per 100 000 population, respectively. The most frequent type of dominant ataxia in our sample was SCA3, and the most frequent recessive ataxia was Friedreich ataxia. The most frequent type of dominant hereditary spastic paraplegia in our sample was SPG4, and the most frequent recessive type was SPG7. CONCLUSIONS: In our sample, the estimated prevalence of ataxia and hereditary spastic paraplegia was 7.73 cases per 100 000 population. This rate is similar to those reported for other countries. Genetic diagnosis was not available in 47.6% of cases. Despite these limitations, our study provides useful data for estimating the necessary healthcare resources for these patients, raising awareness of these diseases, determining the most frequent causal mutations for local screening programmes, and promoting the development of clinical trials.

[Myoadenylate deaminase deficiency in a child with myalgias induced by physical exercise]. / Déficit de mioadenilato desaminasa en un niño con mialgias relacionadas con la actividad física.

INTRODUCTION: Myoadenylate deaminase deficiency (MAD) constitutes the most common genetically determined enzymatic defect of the skeletal muscle (2% of the population), however, it causes clinical symptoms such us exercise-related muscle cramps and pain in quite a lower number of patients, being exceptional in children. CASE REPORT: A 7 year old boy is referred with intense myalgias after physical exertion associating increased creatin kinase level 3,273 UI/L (normal 24-195) which goes down in rest period to increase again with myalgias during exercise. The ischemic forearm exercise test shows a flat ammonia curve with a normal lactate rise in relation to control. In muscle biopsy, an absence of the enzymatic activity of myoadenylate deaminase is observed and the genetic analysis proves the 'nonsense' Q12X mutation which he has in a homozygous status. CONCLUSION: MAD deficiency must be ruled out in every patient with exertional myalgia and increased CK which normalizes when asymptomatic. The ischemic forearm exercise test guides about the muscle metabolic disorder type, although the definitive diagnosis is obtained through the muscle biopsy histoenzymatic analysis and genetic techniques. Although rarely diagnosed in children, MAD deficiency must be included in the differential diagnosis of syndromes with exercise intolerance

Déficit de mioadenilato desaminasa en un niño con mialgias relacionadas con la actividad física / Myoadenylate deaminase deficiency in a child with myalgias induced by physical exercise

Introducción. El déficit de mioadenilato desaminasa (MAD) constituye el defecto enzimático genéticamente determinado más frecuente del músculo esquelético (2 por ciento de la población); sin embargo, produce manifestaciones clínicas en forma de calambres y dolores musculares asociados al ejercicio en un número bastante menor de personas, y es excepcional en los niños. Caso clínico. Se trata de un varón de 7 años, que consulta por intensas mialgias con la actividad física; se acompaña de elevación de creatincinasa a 3.273 UI/L (normal: 24-195), que desciende en períodos de reposo, para ascender con nuevas mialgias con el ejercicio. En el test de ejercicio del antebrazo en isquemia se objetiva una curva plana del amonio, con ascenso normal del lactato respecto al control. En la biopsia muscular se observa la ausencia de actividad enzimática de la MAD, y se confirma mediante estudio genético la mutación nonsense Q12X, que presenta en homocigosis. Conclusión. Se debe descartar un déficit de MAD en todo paciente que presente mialgias asociadas al ejercicio físico con elevación de las enzimas musculares, que descienden al quedar asintomático. El test de ejercicio del antebrazo en isquemia orienta sobre el tipo de trastorno metabólico muscular, aunque el diagnóstico definitivo lo obtendremos mediante el estudio histoenzimático de la biopsia muscular y el estudio genético. A pesar de diagnosticarse raramente en niños, el déficit de MAD debe incluirse en el diagnóstico diferencial de los síndromes que cursan con intolerancia al ejercicio (AU)

Introduction. Myoadenylate deaminase deficiency (MAD) constitutes the most common genetically determined enzymatic defect of the skeletal muscle (2% of the population), however, it causes clinical symptoms such us exercise-related muscle cramps and pain in quite a lower number of patients, being exceptional in children. Case report. A 7 year old boy is referred with intense myalgias after physical exertion associating increased creatinkinase level 3,273 UI/L (normal 24-195) which goes down in rest period to increase again with myalgias during exercise. The ischemic forearm exercise test shows a flat ammonia curve with a normal lactate rise in relation to control. In muscle biopsy, an absence of the enzymatic activity of myoadenylate deaminase is observed and the genetic analysis proves the ‘nonsense’ Q12X mutation which he has in a homozygous status. Conclusion. MAD deficiency must be ruled out in every patient with exertional myalgia and increased CK which normalizes when asymptomatic. The ischemic forearm exercise test guides about the muscle metabolic disorder type, although the definitive diagnosis is obtained through the muscle biopsy histoenzymatic analysis and genetic techniques. Although rarely diagnosed in children, MAD deficiency must be included in the differential diagnosis of syndromes with exercise intolerance (AU)