Geographic and Specialty Access Disparities in US Pediatric Leukodystrophy Diagnosis.

OBJECTIVE: To examine disparities in the diagnosis of leukodystrophies including geographic factors and access to specialty centers. STUDY DESIGN: Retrospective cohort study of pediatric patients admitted to Pediatric Health Information System hospitals. Patients with leukodystrophy were identified with International Classification of Diseases, Tenth Revision, Clinical Modification diagnostic codes for any of 4 leukodystrophies (X-linked adrenoleukodystrophy, Hurler disease, Krabbe disease, and metachromatic leukodystrophy). We used 3-level hierarchical generalized logistic modeling to predict diagnosis of a leukodystrophy based on distance traveled for hospital, neighborhood composition, urban/rural context, and access to specialty center. RESULTS: We identified 501 patients with leukodystrophy. Patients seen at a leukodystrophy center of excellence hospital were 1.73 times more likely to be diagnosed than patients at non-center of excellence hospitals. Patients who traveled farther were more likely to be diagnosed than those who traveled shorter. Patients living in a Health Professionals Shortage Area zip code were 0.86 times less likely to be diagnosed than those living in a non-Health Professionals Shortage Area zip code. CONCLUSIONS: Geographic factors affect the diagnosis of leukodystrophies in pediatric patients, particularly in regard to access to a center with expertise in leukodystrophies. Our findings suggest a need for improving access to pediatric specialists and possibly deploying specialists or diagnostic testing more broadly.

Argentinian clinical genomics in a leukodystrophies and genetic leukoencephalopathies cohort: Diagnostic yield in our first 9 years.

INTRODUCTION AND OBJECTIVES: Leukodystrophies and genetic leukoencephalopathies constitute a vast group of pathologies of the cerebral white matter. The large number of etiopathogenic genes and the frequent unspecificity on the clinical-radiological presentation generate remarkable difficulties in the diagnosis approach. Despite recent and significant developments, molecular diagnostic yield is still less than 50%. Our objective was to develop and explore the usefulness of a new diagnostic procedure using standardized molecular diagnostic tools, and next-generation sequencing techniques. MATERIALS AND METHODS: A prospective, observational, analytical study was conducted in a cohort of 46 patients, evaluated between May 2008 and December 2016, with a suspected genetic leukoencephalopathy or leukodystrophy. A diagnostic procedure was set up using classical monogenic tools in patients with characteristic phenotypes, and next-generation techniques in nonspecific ones. RESULTS: Global diagnostic procedure yield was 57.9%, identifying the etiological pathogenesis in 22 of the 38 studied subjects. Analysis by subgroups, Sanger method, and next-generation sequencing showed a yield of 64%, and 46.1% respectively. The most common pathologies were adrenoleukodystrophy, cerebral autosomal-dominant arteriopathy with subcortical infarcts (CADASIL), and vanishing white matter disease. CONCLUSIONS: Our results confirm the usefulness of the proposed diagnostic procedure expressed in a high diagnostic yield and suggest a more optimal cost-effectiveness in an etiological analysis phase.

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

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.

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. Case Presentation]. / Leucodistrofia metacromática. Presentación de caso.

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 initially diagnosed with schizophrenia, but the Nuclear Magnetic Resonance (NMR) scan and laboratory tests lead to the diagnosis of MLD.

Clinical and biochemical study of 29 Brazilian patients with metachromatic leukodystrophy.

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.

Aspectos clinicos e terapêuticos da Leucodistrofia Metacromática / Clinical and therapeutic aspects of Metachromatic Leukodystrophy

A leucodistrofia metacromática é uma doença genética autossômica recessiva causada pela deficiência de atividade de uma enzima...

Actividad de la enzima aril sulfatasa A en pacientes con desórdenes esquizofrénicos / Aryl sulfatase a levels in patients with schizophrenic disorders

La leucodistrofia metacromática (LDM) es una enfermedad degenerativa causada por la deficiencia de la enzima aril sulfatasa A (ASA), que puede cursar con síntomas psiquiátricos. El propósito de esta investigación fue determinar la prevalencia de la deficiencia de ASA en un grupo de 23 pacientes con esquizofrenia. El valor de la mediana del ASA sérica en ellos fue 53.2 nmol/mL/h (rango 3.3-152-5). Seis (26 por ciento) presentaban actividades baja del ASA sérica (< 27.5 nmol/mL/h que es el límite inferior observado en 29 controles normales). Cinco de ellos tenían historia clínica de delirio de grandez, alucinaciones auditivas, hospitalizaciones múltiples, respuesta pobre a los neurolépticos y potenciales evocados anormales. Es probable que los síntomas esquizofrénicos fueran secundarios a la deficiencia de la enzima. Los hallazgos de este estudio son de utilidad en la clínica ya que ASA puede ayudar a identificar casos de LDM en pacientes presumiblemente esquizofrénicos

[Activity of aryl sulfatase A enzyme in patients with schizophrenic disorders]. / Actividad de la enzima aril sulfatasa A en pacientes con desórdenes esquizofrénicos.

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.

Presymptomatic late-infantile metachromatic leukodystrophy treated with bone marrow transplantation.

At 8 months of age, before clinical neurologic deterioration, the younger of two sisters with metachromatic leukodystrophy received a transplant of bone marrow from her haploidentical, heterozygote mother. Compared with the course in the older, affected, untreated sibling, the onset of neurologic regression was delayed 1 year and progressed at a slower rate.

Pseudodeficiencies of arylsulfatase A and galactocerebrosidase activities.

Pseudodeficiency is defined as the in vitro measurement of low activity (usually under 15% of the normal mean for controls) of an enzyme in a healthy person. They may be hard to distinguish from presymptomatic people who will present with adult-onset clinical disease. The finding of healthy people with low arylsulfatase A and galactocerebrosidase activities is well documented. This confuses the laboratory doing testing and the clinician providing the sample. Therefore confirmation of a diagnosis of metachromatic leukodystrophy and Krabbe disease, as well as accurate identification of carriers, requires additional testing including 14C-sulfatide loading in cultured skin fibroblasts, examination of urine for excretion of undegraded lipids, examination of enzyme levels in additional family members including grandparents, and molecular analysis of DNA samples for known mutations.

Leucodistrofia metacromática infantil tardía / Late infantile metachromatic leukodeptrophy

Presentamos el caso clínico de un niño de 3 años con leucodistrofia metacromática (LDM) infantil tardía y revisamos los avances en el diagnóstico. La enfermedad se caracteriza por: falla motora y retardo mental, disminución de la actividad arilsulfatasa A (ASA), marcada disminición en la velocidad de conducción nerviosa, desmielinización segmentaria, remielinización y metacromasia en las biopsias de nervio sural, disminución difusa de la densidad de la substancia blanca en TAC cerebral y alteraciones de los potenciales evocados

Early manifestations of multiple sulfatase deficiency.

We describe two boys, presenting by 1 year of age, with developmental delay from birth, mildly coarse facial features, and hepatomegaly. These clinical features were most suggestive of a mucopolysaccharidosis, particularly MPS II. Biochemical studies, including sulfate incorporation in fibroblasts and lysosomal enzyme analyses in fibroblasts, leukocytes, and serum, showed abnormalities in both sulfatide and mucopolysaccharide metabolism and led to the diagnosis of multiple sulfatase deficiency. With time, both patients developed an ichthyotic rash and profound intellectual deterioration. We conclude that findings in the first year of life in some patients with MSD may closely resemble those in patients with a MPS disorder rather than the late infantile form of metachromatic leukodystrophy, as is classically described. Thus, MSD should be considered in the young patient suspected of having a MPS disorder.

[Metachromatic leukodystrophy: report of 2 cases with histochemistry of nerves and muscles]. / Leucodistrofia metacromática: relato de dois casos com histoquímica de nervos e músculos.

Two cases of metachromatic leukodystrophy, of the late infantile form are reported. The patients were a girl and a boy of 2 years 10 months old, with initial normal development, but by the age of 18 months began with gait disturbances, difficulty to speak and developed progressive mental deterioration, with signs of long tract involvement, absence of deep tendon reflexes, spasticity, blindness, muscle atrophy and finished in a vegetative state. The diagnosis was made electromyography (signs of denervation), motor nerve conduction velocity (very decreased), assay of arylsulfatase A in the urine (absence of activity), sural nerve biopsy (demyelination and presence of metachromatic granules by the cresyl-violet and toluidine blue) and muscle biopsy (atrophy of type I fibers and presence of metachromatic material in the intramuscular nerve fibers). A quick revision about diagnostic methods, transmission, pathogenesis and variant forms is made.