Enfermedades desmielinizantes: leucodistrofia metacromática y esclerosis múltiple, a propósito de un caso / Demyelinating diseases: metachromatic leukodystrophy and multiple sclerosis, a case study

RESUMEN Las enfermedades desmielinizantes son entidades poco frecuentes en la edad pediátrica; tal es el caso de la esclerosis múltiple y la leucodistrofia metacromática, en las cuales intervienen factores genéticos y ambientales, y ambas afectan diferentes estructuras del sistema nervioso central, los nervios, los músculos, otros órganos y el comportamiento del individuo. Son afecciones que tiene una evolución progresiva al deterioro neuromuscular: en poco tiempo el paciente entra en un estado neurovegetativo con pérdida de la conciencia, por lo que requieren de atención médica y de enfermería especializada. El propósito de este estudio es presentar un caso de leucodistrofia metacromática, haciendo referencia a su complejo diagnóstico diferencial con la esclerosis múltiple y la aplicación del proceso de enfermería. Paciente masculino de 6 años de edad con antecedentes con antecedentes de diversos episodios de infecciones respiratorias y atelectasias, así como estadía prolongada en unidades de cuidados intensivos. Otros síntomas fueron hipotonía muscular, ausencia de reflejos tendinosos y trastornos audiovisuales. A la edad de 6 años el paciente había perdido todo contacto con el medio, sufrió tetraparesia y frecuentes episodios de convulsiones tónicas. A pesar de los intensos tratamientos y seguimientos en diferentes consultas, falleció a los 6 años de edad por complicaciones respiratorias.

ABSTRACT Demyelinating diseases are infrequent entities in pediatric age; such is the case of metachromatic leukodystrophy and multiple sclerosis, in which genetic and environmental factors take action. both of them affect different structures of the central nervous system, nerves, muscles, organs and individual behavior. These affections have a progressive evolution of the neuromuscular deterioration: soon the patient enters a neurovegetative state with loss of consciousness. Therefore, medical attention and specialized nursing is required. The purpose of this study is to present a case of metachromatic leukodystrophy referring to its complex differential diagnosis with multiple sclerosis and nursing process application. A 6-year-old male patient with record of several respiratory infections and atelectasis, such as extended stay at the intensive care unit. Some other symptoms were muscle hypotonia, lack of tendinous reflexes, and audiovisual disorder. At the age of 6 the patient had lost all contact with the environment, suffered from tetra paresis and frequent tonic seizure episodes. Despite the intense treatments and the follow-ups in several medical consultations, the patient passed away at the age of 6 due to respiratory complications.

Analysis of ARSA gene variant in an infant with late infantile metachromatic leukodystrophy / 中华医学遗传学杂志

Objective@#To detect pathogenic variant of ARSA gene in an infant with late infantile metachromatic leukodystrophy (MLD).@*Methods@#The male proband had an onset of walking dysfunction and seizure at 28 months. Arylsulfatase A activity of his peripheral blood leucocytes was 26.9 nmol/mg.17h, and cranial MRI showed wild symmetrical demyelination. With genomic DNA extracted from his peripheral blood sample, all coding exons and splicing sites of the ARSA gene were subjected to Sanger sequencing. PubMed Protein BLAST system was employed to analyze cross-species conservation of the mutant amino acid. Ucsf chimera software was used to analyze the impact of candidate variants on the secondary structure of the protein product. Impact of potential variants was also analyzed with software including PolyPhen-2, Mutation Taster, SIFT and PROVEAN. Whole-exome sequencing was carried out to identify additional variants which may explain the patient’s condition.@*Results@#The proband was found to harbor compound heterozygous variants of the ARSA gene [c.467G>A (p.Gly156Asp) and c. 960G>A (p.Trp320*)], neither of which was reported previously. As predicted by Ucsf chimera software, the c. 960G>A (p.Trp320*) variant may demolish important secondary structures including α-helix, β-strand and coil of the ARSA protein, causing serious damage to its structure and loss of function. The c. 467G>A (p.Gly156Asp) variant was predicted to be "probably damaging" by PolyPhen-2, Mutation Taster and SIFT software.@*Conclusion@#The patient’s condition may be attributed to the compound heterozygous c. 467G>A (p.Gly156Asp) and c. 960G>A (p.Trp320*) variants of the ARSA gene. Above results have facilitated genetic counseling and prenatal diagnosis for this family.

Leucodistrofia metacromática infantil tardía: Presentación de un caso / Late infantile metachromatic leukodystrophy: case report

La leucodistrofia metacromática es una enfermedad autosómi-ca recesiva poco común ocasionada por el déficit de la enzima lisosomal arilsulfatasa A, el cual provoca una desmielinización progresiva con manifestaciones neurológicas subsecuentes. Dentro de sus formas de manifestación, la infantil tardía es la de peor pronóstico. La resonancia magnética juega un papel importante en la caracterización de anormalidades subyacentes, lo que permite descartar otras afecciones clínicas y aproximar un diagnóstico, que, posteriormente, es confirmado mediante los análisis moleculares apropiados. Dado el escaso conocimiento de esta enfermedad, sumado a un curso clínico generalmente fatal, se hace fundamental una identificación temprana y precisa con el fin de iniciar un manejo paliativo y asesoría genética. Se presenta a una paciente femenina de 24 meses de edad con historia de retardo psicomotor y hallazgos imagenológicos compatibles con leucodistrofia. Los estudios enzimáticos y moleculares confirmaron el diagnóstico de leu-codistrofia metacromática infantil tardía.

Metachromatic leukodystrophy is an uncommon autosomal recessive disease caused by the deficiency of the arylsulfatase A lysosomal enzyme, which causes a progressive demyelin-ation with subsequent neurological manifestations. Between its manifestation forms, the one presenting in late childhood has the worst prognosis. Magnetic resonance plays an important role in the characterization of underlying abnormalities, which makes it possible to rule out other clinical conditions and approximate a diagnosis that is later confirmed by the appropriate molecular studies. Given the limited knowledge of the condition, coupled with a generally fatal clinical course, an early and accurate identification is fundamental in order to start palliative management and genetic counseling. A 24 months old female patient with psychomotor retardation history and imaging findings compatible with leukodystrophy is presented. Enzymatic and molecular studies confirmed a diagnosis of late childhood metachromatic leukodystrophy.

Metachromatic leukodystrophy / 国际儿科学杂志

Metachromatic leukodystrophy is an inherited lysosomal disorder caused by autosomal reces-sive mutations of ARSA gene or PASP gene,which result in the accumulation of sulfatides in the central and pe-ripheral nervous system leading to demyelination. The disease is classified into a late-infantile,juvenile and adult onset type based on the age of onset,all characterized by a variety of neurological symptoms,which eventually lead to death if untreated. There is no curative treatment for all types and stages. This review discusses pathogen-esis,clinical manifestations,diagnostic process and efficacy of current and possible future therapies such as en-zyme replacement therapy,hematopoietic stem cell transplantation and gene therapy. A longer follow up period for the above therapies are needed to come to a general conclusion and improve treatment options for metachro-matic leukodystrophy.

Identification of a novel mutation in ARSA gene in three patients of an Iranian family with metachromatic leukodystrophy disorder

Abstract Metachromatic leukodystrophy disorder (MLD) is an autosomal recessive and lysosomal storage disease. The disease is caused by the deficiency of the enzyme arylsulfatase A (ARSA) which is encoded by the ARSA gene. Different mutations have been reported in different populations. The present study was aimed to detect the mutation type of the ARSA gene in three relative Iranian patients. We found a novel homozygous missense mutation c.1070 G > T (p.Gly357Val) in exon 6 of these patients. The mutation was found to be reported for the first time in MLD patients. The data can update the mutation profile and contribute toward improved clinical management and counseling of MLD patients.

Metachromatic leukodystrophy. Case presentation / Leucodistrofia metacromática. Presentación de caso

ABSTRACT Metachromatic leukodystrophy (MLD) is a rare demyelinating disease (prevalence 1:40,000), also called arylsulfatase A deficiency (ARS-A), which may present with neurological and psychiatric symptoms. Clinical assessment may be difficult, due to unspecific signs and symptoms. A case is presented of a 16 year-old female patient seen in psychiatry due to behavioural changes, psychosis, and with impaired overall performance. She was ini tially diagnosed with schizophrenia, but the Nuclear Magnetic Resonance (NMR) scan and laboratory tests lead to the diagnosis of MLD.

RESUMEN La leucodistofia metacromática (LDM) es una enfermedad desmielinizante rara (prevalencia, 1:40.000), también llamada deficiencia de arilsulfatasa A (ARS-A), que puede presentarse con síntomas neurológicos y psiquiátricos y cuyo diagnóstico puede plantear dificultades para el clínico, dado lo inespecífico de los signos y síntomas. Se presenta el caso de una paciente de 16 arios atendida por psiquiatría por cambios conductuales, psicosis y deterioro general del funcionamiento. Inicialmente diagnosticada como esquizofrenia, se documentaron por resonancia magnética y pruebas de laboratorio en la evolución cambios que llevaron al diagnóstico de leucodistrofia metacromática.

A Korean Patient with Early Juvenile Form of Metachromatic Leukodystrophy: Biochemical and Molecular Genetic Investigation

Metachromatic leukodystrophy is an inherited lysosomal storage disorder caused by the deficiency of arylsulfatase A activity. The patient in this study, a 5-yr-old girl, presented with progressive psychomotor regression. An MRI image of her brain showed bilateral symmetrical demyelination. The arylsulfatase A activity in her leukocytes was decreased to 8.0 nmol/hr/mg protein (reference range, 25-80 nmol/hr/mg protein). Mutation analysis of ARSA, using PCR and direct sequencing, showed two heterozygote pathogenic variations of c.449C>T (p.Pro150Leu) and c.640G>A (p.Ala214Thr). In summary, we report a Korean patient with an early juvenile form of metachromatic leukodystrophy, who was diagnosed based on her clinical symptoms as well as by using biochemical, radiological, and molecular genetic investigations.

Biochemical and Genetic Analysis of Seven Korean Individuals With Suspected Metachromatic Leukodystrophy

Metachromatic leukodystrophy (MLD) is an autosomal recessive disease caused by a deficiency in arylsulfatase A (ARSA). However, decreased ARSA activity is also observed in pseudodeficiency (PD). To distinguish between MLD and PD, we performed gene mutation and sulfatide analyses by using dried blood spots (DBSs) from seven Korean individuals who underwent an analysis of ARSA activity. DNA was extracted from DBSs, and PCR-direct sequencing of ARSA was performed. The cDNA obtained was analyzed to confirm a novel mutation. Of the seven subjects, three were confirmed as having MLD, one was confirmed as having MLD-PD, one was confirmed as having PD, and the remaining two were obligate heterozygotes. We verified the novel pathogenic variant c.1107+1delG by performing familial and cDNA analyses. Sulfatide concentrations in DBSs were analyzed and were quantified by using ultra-performance liquid chromatography and tandem mass spectrometry, respectively. Total sulfatide concentration was inversely correlated with ARSA activity (Spearman's coefficient of rank correlation, P=0.929, P=0.0025). The results of this mutational and biochemical study on MLD will increase our understanding of the genetic characteristics of MLD in Koreans.

Significance of arylsulfatase A gene detection for the diagnosis of metachromatic leukodystrophy / 中华实用儿科临床杂志

Objective To detect genetic causes of seizures and developmental retardation in 60 patients with abnormal head magnetic resonance imaging(MRI) ,and to analyze the clinical manifestations and head MRI manifestations in carriers of arylsulfatase A (ARSA) gene mutation.Methods The blood samples of children and genomic DNA were collected.Sixty cases of children with suspected metachromatic leukodystrophy were tested (MLD) by using the second generation sequencing technology.The genotype and phenotype and head MRI findings were analyzed.Results Of the 60 cases of children, 15 cases with gene mutations.There were 7 kinds of ARSA gene mutations, and 3 of them, c.1178C ＞ G, c.1055A ＞ G and c.883 G ＞ A were pathogenic.The others were single nucleotide polymorphism(SNP), which had no relationship with this disease.One of the patients carried only SNP, and 14 of them were carrying pathogenic mutation, c.1055A ＞ G (53.33％) ,c.1178C ＞ G (40.00％) were more common,and c.1055A ＞ G mutation was in 8 cases, of which 5 cases were late-onset type.One case of the 3 patients who were late infantile type was carrying c.1178C ＞ G mutation at the same time.All the eight cases had retardation.One case had hydrocephalus, and 5 cases had epilepsy.All of the 6 patients with c.1178C ＞ G were late-infantile type, and had retardation, including 4 cases of epilepsy, c.883G ＞ A mutation in 1 case,was late-infantile type,and the first symptom was binaural deafness and mental retardation.Three different types of mutations showed no significant difference in brain MRI.Conclusions There are 14 patients who were diagnosed as MLD.c.1178C ＞ G and c.883G ＞ A were late infantile type,and c.1055A ＞G was mostly late-onset type.The changes in head MRI caused by different types of ARSA gene mutations were of no significant differences in performance.

Papilomatose da vesícula biliar associada à leucodistrofia metacromática, uma causa rara de hemobilia não traumática / Papillomatosis of the gallbrander associated with metachromatic leukodystrophy, a rarre cause of nontraumatic hemobilia

A principal causa de hemobilia é a lesão traumática de ramos intra-hepáticos da artéria hepática. Porém, outras etiologias são descritas. O objetivo deste artigo é apresentar uma rara causa de hemorragia digestiva secundária à hemobilia associada à leucodistrofia metacromática. Revisão bibliográfica evidenciou apenas quatro casos descritos.

The main cause of hemobilia is the traumatic injury of intrahepatic branches of the hepatic artery. However, other etiologies are decribed. The objective of this paper is to present a rare case of gastrointestinal bleeding secondary to hemobilia associated with metachromatic leukodystrophy. Literature review revealed only four cases described.

A Case of Metachromatic Leukodystrophy Confirmed by Molecular Genetic Analysis / 대한소아신경학회지

Metachromatic leukodystrophy (MLD) is the rare neurometabolic disease caused by the deficiency of the enzyme arylsulfatase A resulting in a deficiency of sulfatide degradation and the target gene is ARSA gene. We report a case of the late infantile form of MLD that was confirmed by means of enzyme assay and gene analysis with typical brain MRI and MR spectroscopy finding.

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.

Estudio de las enzimas lisosomales N-acetil-a-D-glucosaminidasa y arilsulfatasa A en adultos cubanos / Assay of lysosomal N-acetyl-a-D-glucosaminidase and arylsulfatase A activities in Cuban adults

El objetivo de este estudio fue determinar, en una muestra de individuos cubanos, un rango preliminar de valores normales de actividad específica de N-acetil- a-D-glucosaminidasa y arilsulfatasa A, enzimas deficientes en la mucopolisacaridosis tipo III B y la leucodistrofia metacromática, respectivamente. Se realizó una investigación de corte transversal, en muestras de sangre de 38 individuos adultos. Se realizó la extracción de los leucocitos y se determinó la actividad específica de las enzimas por métodos espectrofotométricos. Todos los participantes fueron caracterizados desde el punto de vista clínico como sanos para ambas enfermedades. Se obtuvieron valores medios de actividad específica de N-acetil-a-D-glucosaminidasa y arilsulfatasa A de 1,52±0,30 y 121,37±20,14 nmol/mg/h, respectivamente. No se encontraron diferencias significativas en relación a las características étnicas para ninguna de las dos enzimas (p<0,05). Este constituye el primer estudio cubano en el cual se publican rangos de actividad específica para estas enzimas en individuos cuya condición de sanos y no relacionados familiarmente con la enfermedad ha sido clínicamente demostrada. El análisis de un mayor número de muestras permitirá establecer los puntos de corte que dotarán al diagnóstico bioquímico de estas enfermedades de una mayor confiabilidad.

The aim of this study was to determine, in a sample of Cuban individuals, a preliminary range of normal values of N-acetyl-a-D-glucosaminidase and arylsulfatase A activity, enzymes that are deficient in mucopolysaccharidosis type III B and metachromatic leukodystrophy, respectively. A cross-sectional research was conducted. Blood samples were obtained out of 38 adult individuals. The leucocytes were extracted and the specific enzymatic activity was assayed by spectrophotometric methods. All participants were characterized from the clinical point of view as healthy for both diseases. Average values of N-acetyl-a-D-glucosaminidase and arylsulfatase A specific activities of 1.52 ± 0.30 and 121.37 ± 20.14 nmol/mg/h, respectively were obtained. There were no significant differences related to ethnicity for any of the two enzymes (p <0.05). This is the first Cuban study in which ranges of activity for these enzymes have been reported in healthy individuals whose healthy and non-familiarly related with the disease status have been clinically demonstrated. The analysis of more samples will establish the cutoff points that will increase the reliability of the biochemical diagnosis of these diseases.

Implicaciones anestésicas de un caso de leucodistrofia metacromática / Anaesthetic implications in a case of metabolic leukodystrophy

Metachromatic leukodystrophy is a progressive, inherited and neurodegenerative disease. A patient suffering from this disease poses a lot of anaesthetic problems. We have successfully anaesthetized a female child with general anaesthesia who was suffering from metabolic leukodystrophy.

La leucodistrofia metacromática es una enfermedad progresiva hereditaria y neurodegenerativa. Un paciente que sufre de esta enfermedad representa múltiples problemas anestésicos. Hemos anestesiado exitosamente una niña que sufre de leucodistrofia metacromática con anestesia general.

Identification of a Novel Splicing Mutation in the ARSA Gene in a Patient with Late-infantile Form of Metachromatic Leukodystrophy / 대한진단검사의학회지

Metachromatic leukodystrophy (MLD; MIM 250100), a severe neurodegenerative disorder inherited as an autosomal recessive trait, is caused by mutations in the arylsulfatase A (ARSA) gene. Although several germ line ARSA mutations have been identified in patients with MLD of various ethnic backgrounds elsewhere in the world, no genetically confirmed cases of MLD have been reported in Korea. Recently, we identified a mutation in the ARSA gene of a Korean male with MLD. A male infant with late-infantile form of MLD had been admitted to our hospital for further examination. His neuromuscular symptoms, which included inability to walk at the age of 12 months, gradually worsened, even after allograft bone marrow transplantation; he died at the age of 9 yr. His elder brother had also been diagnosed with MLD. To confirm the presence of a genetic abnormality, all the coding exons of the ARSA gene and the flanking introns were amplified by PCR. A molecular analysis of the ARSA gene revealed both a novel heterozygous splicing mutation (c.1101+1G>T) in intron 6 and a heterozygous missense mutation in exon 2 (c.296G>A; Gly99Asp). The patient's elder brother who had MLD is believed to have had the same mutation, which may be correlated with a rapidly deteriorating clinical course. This study identified a novel mutation in the ARSA gene, related to a late-infantile form of MLD with a lethal clinical course and suggested that molecular diagnosis of patients may be useful in early diagnosis and for deciding intervention measures for their family members.

A Case of Adult-onset Metachromatic Leukodystrophy with Normal Nerve Conduction Studies

Adult-onset metachromatic leukodystrophy (MLD) is very rare with a combination of cognitive and behavioral symptoms and peripheral polyneuropathy. A 47-year-old man was admitted due to memory impairment, gait disturbance, dysarthria and personality changes for a period of 3 years. The arylsulfatase A level in his leukocytes was decreased. A brain MRI showed bilateral symmetrical demyelination but nerve conduction velocities (NCV) were normal. We report a very rare case of adult-onset MLD with normal NCV.