RESUMO
Metachromatic leukodystrophy (MLD) is a lysosomal disorder caused by arylsulfatase A (ARSA) deficiency. It is classified into three forms according to the age of onset of symptoms (late infantile, juvenile, and adult). We carried out a cross-sectional and retrospective study, which aimed to determine the epidemiological, clinical, and biochemical profile of MLD patients from a national reference center for Inborn Errors of Metabolism in Brazil. Twenty-nine patients (male, 17) agreed to participate in the study (late infantile form: 22; juvenile form: 4; adult form: 1; asymptomatic: 2). Mean ages at onset of symptoms and at biochemical diagnosis were, respectively, 19 and 39 months for late infantile form and 84.7 and 161.2 months for juvenile form. The most frequently reported first clinical symptom/sign of the disease was gait disturbance and other motor abnormalities (72.7%) for late infantile form and behavioral and cognitive alterations (50%) for juvenile form. Leukocyte ARSA activity level did not present significant correlation with the age of onset of symptoms (r = -0.09, p = 0.67). Occipital white matter and basal nuclei abnormalities were not found in patients with the late infantile MLD. Our results suggest that there is a considerable delay between the age of onset of signs and symptoms and the diagnosis of MLD in Brazil. Correlation between ARSA activity and MLD clinical form was not found. Further studies on the epidemiology and natural history of this disease with larger samples are needed, especially now when specific treatments should be available in the near future.
Assuntos
Cerebrosídeo Sulfatase/deficiência , Leucócitos/enzimologia , Leucodistrofia Metacromática/diagnóstico , Adolescente , Idade de Início , Biomarcadores/sangue , Biomarcadores/urina , Brasil/epidemiologia , Cerebrosídeo Sulfatase/sangue , Criança , Pré-Escolar , Estudos Transversais , Técnicas de Diagnóstico Oftalmológico , Progressão da Doença , Eletroencefalografia , Oftalmopatias/diagnóstico , Oftalmopatias/enzimologia , Oftalmopatias/epidemiologia , Feminino , Transtornos Neurológicos da Marcha/diagnóstico , Transtornos Neurológicos da Marcha/enzimologia , Transtornos Neurológicos da Marcha/epidemiologia , Humanos , Lactente , Leucodistrofia Metacromática/tratamento farmacológico , Leucodistrofia Metacromática/enzimologia , Leucodistrofia Metacromática/epidemiologia , Leucoencefalopatias/diagnóstico , Leucoencefalopatias/enzimologia , Leucoencefalopatias/epidemiologia , Imageamento por Ressonância Magnética , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/enzimologia , Transtornos Mentais/epidemiologia , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Sulfoglicoesfingolipídeos/urina , Fatores de Tempo , Adulto JovemRESUMO
Metachromatic leukodystrophy (MLD) is a degenerative disease caused by the deficiency of aryl sulfatase (ASA). It can course with psychiatric symptoms. We determined the prevalence of ASA deficiency in a group of 23 patients with presumable schizophrenia. The median serum ASA was 53.2 nmol/mL/h (range 3.3-152.5). Six patients (26%) showed low ASA activity (< 27.5 nmol/mL/h which is the lowest value observed in 29 normal controls); five of them had clinical history of delusions of grandeur, auditive hallucinations, multiple hospitalizations, low response to neuroleptics, and abnormal evoked potentials. It is probable that the schizophrenic symptoms in these patients may be due to the enzyme deficiency. We conclude that the assay is useful in clinical practice as it may help to identify cases of MLD in patients with suspected schizophrenia.