[Spinocerebellar ataxia type 7: clinical and molecular genetic analysis of a Mexican family]. / Ataxia espinocerebelosa tipo 7: descripcion de una familia mexicana.

INTRODUCTION: Spinocerebellar ataxias (SCA) constitute a group of neurodegenerative diseases characterized by cerebellar disfunction alone or associated with other neurological anomalies. The combination of progressive cerebellar ataxia, macular pigment dystrophy, ophtalmoplegia, spasticity and an autosomal dominant pattern of transmission is characteristic of SCA 7. Genome wide linkage analysis mapped the defective gene to 3p12 13. OBJECTIVE: To describe a Mexican family with SCA 7. CASE REPORTS: We present a family pedigree of 13 individuals with ataxia and other neurologic findings in 3 generations. The evaluation consisted of a complete clinical and neurologic examination; neuropsychologic, neurophysiologic, ophthalmologic, neuroradiologic assessments and a molecular genetic study. The first 2 generations had a history of gait disturbance and visual loss. We objectively found a global cerebellar syndrome, pyramidal signs, visual impairment and ophtalmoparesis in variable grades in all members of the third generation All had progressive retinal degeneration, cerebellar, brainstem and hemispheric atrophy. We observed anticipation phenomena. Genetic analysis of the father of the third generation showed expansion of CAG triplet repeats at the SCA 7 gene. CONCLUSION: The clinical and genetic findings confirmed the diagnosis of SCA 7, and this is the first report in a Mexican family.

Ataxia espinocerebelosa de tipo 7: descripción de una familia mexicana / Spinocerebellar ataxia type 7: description of a mexican family

Introducción. Las ataxias espinocerebelosas (SCA, del inglés spinocerebellar ataxias) forman un grupo de enfermedades neurodegenerativas que se caracterizan por una disfunción cerebelosa, sola o en combinación con otras anormalidades neurológicas. La asociación de ataxia cerebelosa, distrofia macular pigmentaria progresiva, oftalmoplejía, signos piramidales y un patrón de herencia dominante, es característico de la SCA 7; los estudios de genética molecular han identificado la alteración en el cromosoma 3p12-13.Objetivo. Describir una familia mexicana con SCA 7. Casos clínicos. Se presenta el caso de una familia de 13 individuos de tres generaciones con ataxia y otros signos neurológicos. La evaluación consistió en una historia clínica y un examen neurológico completo, estudios neuropsicológicos, neurofisiológicos, oftalmológico, neurorradiológico y genético molecular. Las primeras dos generaciones tuvieron una historia de alteración en la marcha y disminución de la agudeza visual; en todos los miembros de la última generación se comprobó un síndrome cerebeloso global, piramidalismo, afectación visual y oftalmoparesia en grado variable, maculopatía con degeneración retiniana progresiva, atrofia del cerebelo, el tronco encefálico y los hemisferios cerebrales. Existió un fenómeno clínico de anticipación. El ADN del padre de la última generación mostró una expansión repetida de los tripletes CAG en el gen de SCA 7.Conclusión. Los hallazgos clínicos y genéticos demuestran que se trata de una SCA 7. Es la primera publicación de SCA 7 en una familia mexicana (AU)

Introduction. Spinocerebellar ataxias (SCA) constitute a group of neurodegenerative diseases characterized by cerebellar disfunction alone or associated with other neurological anomalies. The combination of progressive cerebellar ataxia, macular pigment dystrophy, ophtalmoplegia, spasticity and an autosomal-dominant pattern of transmission is characteristic of SCA-7. Genome-wide linkage analysis mapped the defective gene to 3p12-13. Objective. To describe a Mexican family with SCA-7. Case reports. We present a family pedigree of 13 individuals with ataxia and other neurologic findings in 3 generations. The evaluation consisted of a complete clinical and neurologic examination; neuropsychologic, neurophysiologic, ophthalmologic, neuroradiologic assessments and a molecular genetic study. The first 2 generations had a history of gait disturbance and visual loss. We objectively found a global cerebellar syndrome, pyramidal signs, visual impairment and ophtalmoparesis in variable grades in all members of the third generation All had progressive retinal degeneration, cerebellar, brainstem and hemispheric atrophy. We observed anticipation phenomena. Genetic analysis of the father of the third generation showed expansion of CAG triplet repeats at the SCA-7 gene. Conclusion. The clinical and genetic findings confirmed the diagnosis of SCA-7, and this is the first report in a Mexican family (AU)