Next generation sequencing for rapid diagnosis of a rare early onset spastic paraplegia: A novel pathological variant in FA2H gene / Secuenciación de nueva generación para el diagnóstico rápido de una paraparesia espástica rara de aparición infantil: nueva variante patológica en el gen FA2H

Introduction: Hereditary spastic paraplegia is a group of inherited neurological disorders with predominant manifestations of lower extremity weakness and severe spasticity. This is a genetically heterogeneous disorder very difficult to distinguish clinically with many genes described. Few patients with this condition have been previously reported. Patient and methods: We present a case of a 5 years old girl, born from consanguineous parents, with severe ataxia and progressive spasticity of low limbs. Due to the severity of the symptoms and the need for early diagnosis, next generation sequencing study of 37 genes implicated in spastic paraplegia was performed. Results: A novel pathological variant in FA2H gene was discovered. Father, mother and brother were heterozygous carriers. Conclusions: Spastic paraplegia due to mutations in FA2H is an under diagnosed condition, and it should always be considered in childhood onset of progressive pyramidal dysfunction. Next Generation Sequencing allows a simultaneous analysis of many genes, enables a fast diagnosis in complex disorders

Introducción: La paraparesia espástica es un grupo de enfermedades neurológicas hereditarias que cursan con debilidad de las extremidades inferiores y espasticidad severa. Es una enfermedad muy heterogénea, con muchos genes descritos y muy difícil de distinguir clínicamente. Hay pocos pacientes descritos con esta enfermedad. Pacientes y métodos: Se presenta un caso de una niña de 5 años, de padres consanguíneos, con una ataxia severa y espasticidad progresiva de los miembros inferiores. Dada la gravedad de la clínica y la necesidad de un diagnóstico temprano, se decide realizar un panel de secuenciación masiva de 37 genes implicados en paraparesia espástica. Resultados: Los resultados muestran una variante patológica no descrita previamente en el gen FA2H. El padre, la madre y el hermano resultan portadores heterocigotos. Conclusiones: La paraparesia espástica debida a mutaciones en el gen FA2H está infradiagnosticada y debería ser considerada siempre que aparezcan síntomas en la infancia de disfunción piramidal grave y progresiva. Los paneles de secuenciación masiva con el análisis simultáneo de varios genes están permitiendo un diagnóstico más rápido en enfermedades complejas

Improvement in strategies for the non-invasive prenatal diagnosis of Huntington disease.

PURPOSE: We focused on the improvements of prenatal diagnosis by the analysis of DNA from maternal plasma, using Huntington disease as a model of disease. METHODS: We studied plasma from a pregnancy at risk of having a fetus affected with Huntington disease by the use of two direct analysis of the mutation and polymorphic STRs. RESULTS: Direct methods were not informative. Analysis with STRs revealed the presence of the allele that does not co-segregate with the disease, thus the fetus was healthy. CONCLUSIONS: This strategy is very useful to face complex cases when the direct study is not informative not only for Huntington disease but also for many other disorders.