General anesthesia for an adolescent with Pelizaeus-Merzbacher disease: A case report

Pelizaeus-Merzbacher disease (PMD) is a progressive and degenerative chromosomal disorder of the central nervous system caused by defective myelin production. Few case reports have been issued on the anesthetic management of PMD, because of its extremely low incidence. We anesthetized a 13-year-old female patient diagnosed with PMD for ophthalmic surgery because of intermittent exotropia. General anesthesia was induced and maintained with propofol and sevoflurane in air and oxygen. Rocuronium was administered to facilitate orotracheal intubation, and residual neuromuscular blockage was reversed with pyridostigmine. Between emergence to 24 hours postoperatively, her muscle power completely recovered and no unpredictable events occurred. Summarizing, anesthesiologists should be concerned about the high possibility of aspiration, spasticity, and seizure during the perioperative period in patients with even mild PMD. Appropriate preoperative evaluation, intraoperative monitoring, and choice of proper anesthetic drugs enable safe anesthesia in patients with PMD.

Clinical and mutational spectrum of Colombian patients with Pelizaeus Merzbacher Disease / Heterogeneidad clínica y mutacional en pacientes colombianos con Pelizaeus Merzbacher

Abstract Case Presentation: Pelizaeus Merzbacher Disease (PMD) is an X-linked developmental defect of myelination that causes childhood chronic spastic encephalopathy. Its genetic etiology can be either a duplication (or other gene dosage alterations) or a punctual mutation at the PLP1 locus. Clinically, it presents with developmental delay, nystagmus and, spasticity, supported by neuroimaging in which the defect of myelination is evident. We present a series of seven Colombian patients diagnosed with this leucodystrophy, describing their genotypic and phenotypic characteristics and heterogeneity. Clinical Findings: All patients included were male, 6 months to 16 years of age. Mean age at onset of symptoms was 8 months. Mean age at diagnosis was 5 years 5 months, being classic PMD most frequently diagnosed, as compared to the connatal phenotype. All cases had a primary diagnosis of developmental delay on 100%, and in 28.7% of cases, early onset nystagmus was described. 85.7% of patients had spasticity, 71.4% cerebellar signs, 57.0% hypotonia, and 28.5% had an abnormal movement disorder. Only three patients were able to achieve gait, though altered. In the two patients who had a diagnosis of connatal PMD maturational ages in danger zones according to the WHO Abbreviated Scale of Psychosocial Development were documented. All cases had abnormalities in neuroimages. Molecular Analysis and Results: Molecular studies were used in the majority of the cases to confirm the diagnosis (85.7 %). For two cases molecular confirmation was not considered necessary given their affected male brothers had already been tested. PLP1 gene dosage alterations (duplications) were found in 28.5 % of the patients (two siblings), whereas three different single nucleotide variants were detected. Clinical Relevance: According to these findings, as authors we propose the diagnostic algorithm in Colombian population to begin on a high clinical suspicion, followed by paraclinical extension, moving on to the molecular confirmation by using approaches to simultaneously sequence the PLP1 gene in order to detect point mutations and in/dels and performing a copy number variation analysis for the detection of gene dosage alterations.

Resumen Descripción del caso: La enfermedad de Pelizaeus Merzbacher es una leucodistrofia ligada al X que causa encefalopatía espástica crónica en la infancia. Su etiología es genética, por duplicaciones u otros trastornos de la dosis génica o mutaciones puntuales del gen PLP1, lo que condiciona la formación anormal de las vainas de mielina principalmente en el sistema nervioso central. Clínicamente se caracteriza por un cuadro de retardo del neurodesarrollo, nistagmus y espasticidad, con neuroimágenes que evidencian la dismielinización. Presentamos una serie de siete casos colombianos con esta leucodistrofica en la que describimos fenotípica y genotípicamente la heterogeneidad de esta enfermedad en nuestra población. Hallazgos clínicos: Todos los pacientes analizados fueron de sexo masculino, con edad promedio de inicio de síntomas hacia los ocho meses de vida. La edad media al diagnóstico fue de 5 años 5 meses, siendo más frecuente el diagnóstico de PMD clásica que el tipo connatal. Se describe retardo del desarrollo motor en el 100% de los casos, acompañado de nistagmus en el 28.7%. 85.7% de los casos tenía algún grado de espasticidad, 71.4 % signos cerebelosos, 57.0% hipotonía, y hasta en 28.5% se evidenciaron movimientos anormales. Solo tres pacientes lograron marcha, aunque patológica. En los dos pacientes con la forma connatal se documentó una edad maduracional motora en el rango de Alerta, de acuerdo a la escala abreviada del desarrollo de la OMS. En todos los casos se detectó algún tipo de anormalidad en el estudio imagenológico cerebral. Estudios Moleculares y Resultados: El diagnóstico molecular se empleó en la mayoría de los casos (85.7%), encontrando alteraciones en la dosis génica en el 28.5% y tres diferentes mutaciones puntuales. Relevancia clínica: Dados los hallazgos en los resultados del estudio molecular, sugerimos que en el abordaje diagnóstico confirmatorio para la población colombiana se debería contemplar en un mismo tiempo tanto la secuenciación como el estudio de variantes del número de copias del gen afectado, contrario a lo sugerido en literatura mundial en la que se inicia con estudio para duplicación / deleción.

Research progress of genotype and phenotype in proteolipid protein 1-related disorders / 中华实用儿科临床杂志

Proteolipid protein 1 (PLP1)-related disorders are a series rare X-linked recessive disorders caused by mutations of PLP1 gene.There is a spectrum of PLP1-related disorders from very severe connatal PelizaeusMerzbacher disease(PMD,MIM# 312080),through classical PMD to mild spastic paraplegia type 2 (SPG2,MIM# 312920),with some correlation between the type of mutation and the phenotype.The genotype of PLP1-related disorders was constantly discovered and updated,meanwhile there was obvious heterogeneous within clinical phenotypes.Moreover,there were so many diseases similar to PLP1-related disorders.Therefore,there was a huge challenge when clinician met with PLP1-related disorders.The aim of this report is to summarize correlation between the genotype and the phenotype of PLP1-related disorders,and give a help for clinician to diagnose this group complicated disorders.

Magnetic resonance imaging and spectroscopic analysis in 5 cases of Pelizaeus-Merzbacher disease: metabolic abnormalities as diagnostic tools / 소아과

Pelizaeus-Merzbacher disease (PMD) is a rare, X-linked recessive disorder characterized by dysmyelination in the central nervous system. PMD results from deletion, mutation, or duplication of the proteolipid protein gene (PLP1) located at Xq22, leading to the failure of axon myelination by oligodendrocytes in the central nervous system. PMD may be suspected when there are clinical manifestations such as nystagmus, developmental delays, and spasticity, and genetic analysis can confirm the diagnosis. Further diagnostic manifestations of the disease include a lack of myelination on brain magnetic resonance (MR) imaging and aberrant N-acetyl aspartate (NAA) and choline concentrations that reflect axonal and myelination abnormalities on phroton MR spectroscopy. We report 5 cases of PMD (in 1 girl and 4 boys). PLP1 duplication was detected in 2 patients. Brain MR analyses and MR spectroscopy were performed for all the patients. The brain MR images showed white matter abnormalities typical of PMD, and the MR spectroscopic images showed diverse patterns of NAA, creatinine, and choline concentrations. We propose that MR spectroscopic analysis of metabolic alterations can aid the PMD diagnosis and can contribute to a better understanding of the pathogenesis of the disease.

Gene mutations and prenatal diagnosis in six pedigrees with Pelizaeus-Merzbacher disease / 中华围产医学杂志

Objective To investigate proteolipid protein 1 (PLP1) mutations in six pedigrees with Pelizaeus-Merzbacher disease (PMD),and to provide prenatal consulting and prenatal diagnosis.Methods Subjects were six probands with PMD admitted in Department of Pediatrics,Peking University First Hospital from July 2006 to November 2011 and their family members.Genomic DNA sarnples were extracted from peripheral bloods of probands and their family members.Multiplex ligation-dependent probe amplification (MLPA) technique was used to detect PLP1 duplication mutation.Direct DNA sequencing was used to detect point mutation.Genetic diagnosis were based on PLP1 mutation genotype from probands.Prenatal diagnosis of nine fetuses were performed from seven PLP1 mutation female carriers by fetuses' DNA extracted from amniocytes or villus cells.Results PLP1 duplications were found in probands 1-4 (P1-4) whose mothers and the aunt of proband 1 (P1) were PLP1 duplications carriers.The two cases of point mutation,c.96C＞G(p.F32L) and c.623G＞T (p.G208V),were found in proband 5 (P5) and proband 6 (P6).Hcterozygous changes of the same mutations were found in P5' and P6' mothers with normal phenotypes.Seven female PLP1 mutation carriers were pregnant again.Prenatal diagnosis of PLP1 for nine fetuses presented one PLP1 duplication,one point mutation,one PLP1 duplication carrier,and six wildtypes.A segmental crossing over of X chromosome was detected in one male fetus of PLP1 wildtype.Conclusions PLP1 mutation analysis could help to diagnose PMD pedigree and to identify female PLP1 mutation carrier in the family.The following prenatal diagnosis and proper genetic counseling are very important to prevent PMD child from being delivered.

Clinical Manifestations of Leukodystrophies: A Single Center Study / 대한소아신경학회지

PURPOSE: Leukodystrophies have been defined as inherited metabolic disorders of myelin resulting in abnormal development or progressive destruction of the white matter. This study was performed to investigate the clinical manifestations and treatments of leukodystrophies in a single Korean tertiary center. METHODS: We retrospectively analysed the medical records of patients who had been diagnosed with leukodystrophy from May 1995 to May 2010 at the Asan Medical Center. RESULTS: During the 15-year study period, 36 cases of leukodystrophies were diagnosed with an verage age at symptom presentation of 49 months. Prominent symptoms at presentation were developmental delay (41%) and seizure (25%); however, nystagmus, developmental regression, hearing loss, gait disturbance, visual disturbance, attention deficit, hypotonia, hyperpigmentation, and hemiparesis were also observed. On MRI, periventricular involvement was noted frequently. The most common diagnoses were adrenoleukodystophy (25%), metachromatic leukodystrophy (11%), Krabbe disease (11%), and Pelizaeus-Merzbacher disease (8.3%). No final diagnosis was made in 14 cases (41%). Bone marrow transplantation was performed in 4 patients and showed favorable prognoses. CONCLUSION: Clinical features of leukodystrophies are not specific to diagnosis and most leukodystrophies remain undiagnosed; however, a logical algorithm based on prevalence could aid the laboratory testing. Because early detection and diagnosis is crucial for treatment and prognosis, it is important to have a high index of suspicion and watchful screening of familial history.

Identification of Proteolipid Protein 1 Gene Duplication by Multiplex Ligation-Dependent Probe Amplification: First Report of Genetically Confirmed Family of Pelizaeus-Merzbacher Disease in Korea

Pelizaeus-Merzbacher disease (PMD) is a rare X-linked recessive disorder with a prototype of a dysmyelinating leukodystrophy that is caused by a mutation in the proteolipid protein 1 (PLP1) gene on the long arm of the X chromosome in band Xq22. This mutation results in abnormal expression or production of PLP. We here present a Korean boy with spastic quadriplegia, horizontal nystagmus, saccadic gaze, intentional tremor, head titubation, ataxia, and developmental delay. The brain magnetic resonance imaging (MRI) showed abnormally high signal intensities in the white matter tract, including a subcortical U fiber on the T2-weighted and fluid attenuated inversion recovery (FLAIR) image. The chromosomal analysis was normal; however, duplication of the PLP1 gene in chromosome Xq22 was detected when the multiplex ligation-dependent probe amplification (MLPA) method was used. We also investigated the pedigree for a genetic study related to PMD. This case suggests that the duplication mutation of the PLP1 gene in patients with PMD results in a mild clinical form of the disorder that mimics the spastic quadriplegia of cerebral palsy.

Pelizaeus-Merzbacher Disease: A case report

Pelizaeus-Merzbacher disease (PMD) is an X-linked recessive disorder characterized by dysmyelination of the central nervous system (CNS) caused by mutations in the proteolipid protein (PLP) gene. PLP is located at Xq22 and its mutation result in abnormal expression or production of PLP, the most abundant protein in CNS myelin. We present a case of PMD in the 7-year-old boy with nystagmus, ataxia, spastic quadriplegia and severe psychomotor delay. His brain MRI revealed totally dysmyelinated white matter involving entire supratentorial region, atrophic change, and overaccumulation of the iron in both basal ganglia. He also showed soft-tissue contractures of the hip adductors, associated hip dislocations and equinovarus foot deformities due to severe spasticity of lower extremities. Orthopaedic surgery was performed on both hips. Antispastic medication and physical therapy were maintained for reduction of spasticity. We report this case with the review of literatures.

Two Cases of Pelizaeus-Merzbacher Disease

Pelizaeus-Merzbacher disease (PMD) is a rare sudanophilic leukodystrophy with a reduced number of mature oligodendrocytes as well as diffuse central nervous system hypomyelination (dysmyelination) due to abnormal synthesis of proteolipid protein. PMD is characterized with pendular nystagmus, stridor, delay in psychomotor development, hypotonia, ataxia, athetosis and extrapyramidal signs. Abnormal high signal intensity is shown in the entire white matter of cerebrum and cerebellum at early stage by T2-weighted magnetic resonance imaging (MRI). We report two cases of PMD diagnosed with characteristic clinical manifestations and brain MRI findings.