Enfermedad de Krabbe. A propósito de un caso clínico / Krabbe's disease. Apropos of a clinical case

La enfermedad de Krabbe es una afección genética con mecanismo de herencia autosómico y recesivo de muy baja incidencia. Esta determinada por deficiencia en la actividad de la enzima lisosomal galactocerebrósido-ß-galactosidasa (o galactosilcerebrosidasa). Tiene diferentes formas clínicas: infantil, juvenil y de la edad adulta. En Uruguay las enfermedades genéticas son una causa importante de morbi-mortalidad. El reconocimiento por parte del pediatra de elementos clínicos en forma precoz, es clave en el diagnóstico oportuno. Se presenta el caso de una niña con la forma infantil de enfermedad de Krabbe cuyas manifestaciones clínicas se iniciaron a los 7 meses de vida y el diagnóstico se confirmó a los 10 meses por dosificación de la actividad galactocerebrósido-ß-galactosidasa. El objetivo de esta comunicación es jerarquizar el reconocimiento oportuno de las manifestaciones clínicas, revisar los conocimientos actuales en relación al diagnóstico, incluyendo el diagnóstico prenatal, en vistas al asesoramiento genético.

Diagnóstico de leucodistrofia de Krabbe por microscopia electrónica de transmisión: informe de un paciente / Diagnosis of Krabbe's leukodystrophy by transmission electron microscopy: case report

La leucodistrofia de Krabbe es una enfermedad rara en México, por este motivo se reporta un caso de una niña de 11 años. Se describen los estudios ultraestructurales de biopsia de nervio sural. Las vainas de mielina fueron muy delgadas. El citoplasma de las células de Schwann contenía estructuras no membranosas y estructuras en forma de agujas parcialmente curvilíneas de longitud variable. Las inclusiones a menudo tenían material electrodenso o electrolúcido. Estas características representan a la leucodistrofia de Krabbe. Los estudios ultraestructurales ayudan al diagnóstico en los casos en que no se dispone de estudios genéticos o técnicas especiales de laboratorio. En la paciente descrita el diagnóstico de enfermedad de Krabbe se estableció tardíamente de acuerdo con el inicio de los síntomas. El diagnóstico de leucodistrofia de Krabbe se puede evidenciar con el estudio de microscopia electrónica de nervio sural.

Krabbe's leukodystrophy is a rare hereditary disease in Mexico. For that reason we report the case of an 11-year-old child. Ultrastructural studies of sural nerve biopsy specimen are described. Myelin sheaths were uniformly thin for the fiber diameters. Cytoplasm of Schwann cells exhibited a moderate dilatation with non-membrane masses with partly curvilinear, needle-shaped structures of variable length. The inclusions often had electron-dense or electron-lucent halos. These inclusions ultrastructurally represented Krabbe's leukodystrophy, and this method aids in the diagnosis in cases that are not available for genetic studies or special laboratory techniques. In this patient, diagnosis of Krabbe's disease was delayed and established several years after the initial symptoms. Electron microscopic examination of a sural nerve provided evidence for a diagnosis of Krabbe's leukodystrophy.

Krabbe disease--a case report.

Krabbe disease is an extremely rare condition with an incidence of 1 in 1,00,000 live births. It is caused by deficient activity of the Iysosomal hydrolase galactosylceramide beta-galactosidase. A 6 years old male weighing 12 kg, was brought to Rajah Muthiah Medical College and Hospital with complaints of convulsions. The full-term child was delivered by lower segment caesarean section to second-degree consanguineous parents. The baby cried immediately after birth. The child attained normal milestones till two years of age. Thereafter he lost his attained milestones. The child had dysmorphic face with features like anti-Mongoloid eyes and teeth anomaly. Skin was lax all over the body especially over the face and was bruised. Respiratory distress and upward gaze were present. Bilateral crepitations were heard. Pupils were dilated and sluggishly reacted to light.

Leukodystrophies: Indian scenario.

The leukodystrophies are familial disorders with onset usually in infancy or childhood. The clinical features consist of motor dysfunction with varying degree of cognitive decline. Magnetic Resonance Imaging (MRI) has helped to identify and characterize these disorders. In some leukodystrophies, biochemical enzymatic and genetic defects have been identified. The commonest leukodystrophy seen in India is Megalencephalic Leukodystrophy with subcortical cysts. The essential features consist of large head, mild pyramidal and cerebellar dysfunction, and occasional seizures. MRI studies show extensive white matter changes with temporal cysts. It is common in the Agarwal community in India. An identical mutation in exon 2 of the MLC 1 gene has been identified in this community suggesting a founder effect.

Krabbe disease--clinical profile.

OBJECTIVE: To study clinical features and investigations of children with Krabbe Disease (KD). DESIGN: Retrospective. SETTING: Genetic Clinic of a tertiary care teaching hospital. METHODS: Hospital records of patients with enzymatically confirmed KD were analyzed with respect to their clinical features and investigations including neuroimaging (CT-scan and/or MRI). Galactocerebrosidase (GALC) activity was estimated photometrically in the peripheral blood leukocytes. RESULTS: Nine children (age ranging from 2 1/2 months to 8 years) were studied, of which 5 had the classical infantile disease, 3 had late infantile form and one was diagnosed as juvenile KD. GALC levels in peripheral blood leukocytes were low or absent in all. Most of the children with infantile disease presented with neurodegeneration, seizures or fever. Optic atrophy was uncommon in our series (present only in a single case). Majority of the cases had elevated cerebrospinal fluid (CSF) protein levels and peripheral neuropathy on nerve conduction (NC) studies. Findings typical of KD were noted in 7 patients who underwent magnetic resonance imaging (MRI). The sole patient with juvenile disease presented with developmental delay and progressive spastic quadriparesis. CONCLUSION: Krabbe disease should be considered in the differential diagnosis of early infantile onset of neurodegeneration with seizures. Likewise, older children with progressive ataxia or spastic quadriparesis in whom the etiology remains obscure, must be investigated for Krabbe disease. MRI can be diagnostic in absence of availability of enzyme diagnosis.

Adrenoleucodistrofia ligada al cromosoma X: informe de dos casos clínicos / Adrenoleukodystrophy linked with chromosome X. Report of two clinical cases

La adrenoleucodistrofia infantil es un trastorno peroxisomal caracterizado por una falla en la función de la lignoceroil CoA sintetasa, se transmite en forma reseciva ligada al cromosoma X, con localización el locus 28 (q28). La deficiencia enximática condiciona una degradación imcompleta de los ácidos grasos de cadena larga, acumulándose en consecuencia en el tejido cerebral y adrenal. El motivo del presente trabajo es identificar los hallazgos clínicos encontrados en estos casos donde incluímos la presencia del asma bronquial, manifestaciones endocrinológicas y neurológicas. Los pacientes fueron tratados en el servicio a partir de 1990. Se describen los métodos utilizados para el diagnóstico, desde las alteraciones tempranas de los potenciales evocados de tallo, hasta las imágenes de tomografía computarizada de cráneo con doble cantidad de medio de contraste, y cortes tardíos

Doença de Krabbe (leucodistrofia a células globóides): a propósito de cinco observaçöes / Krabbe's disease (globoid cell leukodystrophy): apropos of 5 cases

Foi realizado estudo clínico de 5 observaçöes da doença de Krabbe (leucidistrofia a células globóides). O diagnóstico de certeza, seja pelo estudo neuropatológico pós mortem (2 casos), seja pela dosagem enzimática em fibroblastos em cultura (2 casos), foi alcançado em 4 observaçöes. A biópsia de nervo periférico foi realizada nos 5 casos e o estudo ultrastrutural revelou, em todos, alteraçöes características da doença de Krabbe. Os autores chamam a atençäo para os principais dados clínicos e laboratoriais que sugerem o diagnóstico da doença, mesmo na impossibilidade da realizaçäo de exame ultrastrutural de nervo periférico e das dosagens enzimáticas, estas näo realizadas em nosso país