[Duplication of the PLP gene and the classical form of Pelizaeus-Merzbacher disease]. / Duplicación del gen PLP y forma clásica de la enfermedad de Pelizaeus-Merzbacher.

INTRODUCTION: Pelizaeus-Merzbacher disease (PMD) is a rare form of sudanophilic leukodystrophy which is transmitted by recessive inheritance linked to the X chromosome. It only affects the myelin of the central nervous system (CNS) and is caused by a proteolipid protein (PLP) deficit, which is coded for in Xq21.2-q22. Presentation follows a classical or connatal pattern and is associated with nystagmus, stridor and pyramidal/extrapyramidal manifestations within the framework of a clinical picture of psychomotor retardation and regression with variable clinical course and presentation. CASE REPORT: A 37-month-old male, with sever psychomotor retardation, nystagmus and choreoathetotic movements with a stationary developmental profile. An MRI scan of the brain showed severe supratentorial hypomyelination and peripheral electrophysiological explorations (EMG and NCS) were normal. The genetic study using PCR revealed duplication in the PLP gene. CONCLUSION: This observation corresponds to a classical form of PMD, which must be taken into account when associated with: 1) Psychomotor retardation; 2) Early nystagmus; 3) Pyramidal/extrapyramidal involvement; 4) Absence of peripheral neurophysiological involvement; 5) A neuroradiological pattern of hypomyelination of the CNS.

Duplicación del gen PLP y forma clásica de la enfermedad de Pelizaeus-Merzbacher / Duplication of the PLP gene and the classical form of Pelizaeus-Merzabacher disease

Introducción. La enfermedad de Pelizaeus-Merzbacher (EPM) es una rara forma de leucodistrofia sudanófila transmitida de forma recesiva ligada al cromosoma X. Afecta exclusivamente a la mielina del sistema nervioso central (SNC) y la causa una deficiencia de la proteína proteolipídica (PLP), codificada en Xq21.2q22. Se manifiesta según un patrón clásico o congénito y asocia nistagmo, estridor y manifestaciones piramidoextrapiramidales en el marco de un cuadro de retraso psicomotor y regresión, de presentación y curso clínico variables. Caso clínico. Varón de 37 meses de edad, con grave retraso psicomotor, nistagmo y movimientos coreoatetósicos con un perfil evolutivo estacionario. La RM cerebral mostró una grave hipomielinización supratentorial y las exploraciones electrofisiológicas periféricas (EMG y VCN) fueron normales. El estudio genético mediante PCR mostró duplicación en el gen PLP. Conclusión. La presente observación corresponde a una forma clásica de la EPM, que debe considerarse ante la asociación de: 1) Retraso psicomotor; 2) Nistagmo precoz; 3) Afectación piramidoextrapiramidal; 4) Ausencia de afectación neurofisiológica periférica, y 5) Patrón neurorradiológico de hipomielinización del SNC (AU)

Introduction. Pelizaeus-Merzbacher disease (PMD) is a rare form of sudanophilic leukodystrophy which is transmitted by recessive inheritance linked to the X chromosome. It only affects the myelin of the central nervous system (CNS) and is caused by a proteolipid protein (PLP) deficit, which is coded for in Xq21.2-q22. Presentation follows a classical or connatal pattern and is associated with nystagmus, stridor and pyramidal/extrapyramidal manifestations within the framework of a clinical picture of psychomotor retardation and regression with variable clinical course and presentation. Case report. A 37-month-old male, with sever psychomotor retardation, nystagmus and choreoathetotic movements with a stationary developmental profile. An MRI scan of the brain showed severe supratentorial hypomyelination and peripheral electrophysiological explorations (EMG and NCS) were normal. The genetic study using PCR revealed duplication in the PLP gene. Conclusion. This observation corresponds to a classical form of PMD, which must be taken into account when associated with: 1) Psychomotor retardation; 2) Early nystagmus; 3) Pyramidal/extrapyramidal involvement; 4) Absence of peripheral neurophysiological involvement; 5) A neuroradiological pattern of hypomyelination of the CNS (AU)