ABSTRACT
La Enfermedad de Krabbe (EK), es un desorden del metabolismo de esfingolípidos de herencia autosómica recesiva causada por la deficiencia de β-galactosilceramidasa (β-Galsil) (E.C. 3.2.1.46), defecto enzimático que causa un cuadro neurodegenerativo, hipertonía muscular y espasticidad, convulsiones, pérdida de la audición y en un 85% de los casos la muerte temprana, entre otros hallazgos. La incidencia de la EK documentada para Estados Unidos y Europa es de 1:100.000 recién nacidos, pero estudios recientes han demostrado valores mayores de 1:22.000 aproximadamente en New York. En América Latina los informes son escasos, con reportes de tamizaje de alto riesgo en Brasil y casos aislados en México, ofreciendo un panorama de subdiagnóstico importante, situación a la que no es ajena Colombia, donde no hay en la literatura referentes a la enfermedad. Se presenta entonces a la comunidad científica, un estudio de valores de actividad y de referencia para la enzima β-Galactosilceramidasa leucocitaria, a partir de 259 muestras de 110 individuos sanos y 149 pacientes con compromiso neurodegenerativo (CND). La valoración enzimática involucró dos métodos (Colorimétrico y Fluorométrico) de punto final que permitieron establecer un rango de referencia para β-Galsil en técnica Colorimétrica: 2,04-14,93 nmol/mgprot/h y en técnica fluorométrica: 0,3-4,21 nmol/mgprot/h. El estudio de tamizaje permitió identificar un paciente afectado con enfermedad de Krabbe quien presentó valores de actividad expresados en nmol/mgprot/h de 1,85 y 0,034, en forma correspondiente para las técnicas antes descritas. Un hallazgo final que permite validar los dos métodos estandarizados para el diagnóstico de la enfermedad y establecer valores de referencia en población colombiana.
Krabbe disease is a disorder of autosomal recessive sphingolipid metabolism caused by deficiency β-galactosylceramidase (β-Galsil) (EC3.2.1.46), an enzymatic defect that causes a hurt neurodegenerative, muscular hypertonia and Spasticity, convulsions, hearing loss and in 85% of cases early death, among other findings. The incidence documented for "Krabbe disease" in the United States and Europe is 1:100.000 newborns, but recent studies have shown values greater than 1:22.000 in New York. In Latin America, reports are limited, with reports of high-risk screening in Brazil and isolated cases in Mexico, providing an important underdiagnosis scenario, a situation that is not unknown in Colombia, where there is no literature on the disease. A study of activity and reference values for β-galactosylceramidase enzyme leukocytal, was then presented to the scientific community, from 259 samples from 110 healthy people and 149 patients with neurodegenerative compromise. The enzymatic evaluation involved two methods (Colorimetric and Fluorometric) that allowed the establishment of a reference range for β-Galsil in Colorimetric technique: 2.04-14.93 nmol/mgprot/h and in fluorometric technique: 0.3-4.21 nmol/mgprot/h. The screening study allowed the identification of a patient with Krabbe disease who presented activity values expressed in nmol/mgprot/h of 1.85 and 0.034, correspondingly to the techniques described above. A final finding that allows to validate the two standardized methods for the diagnosis of the disease and to establish reference values in Colombian population.
A doença de Krabbe é uma desordem do metabolismo de esfingolípidos autossômicos recessivos causada pela deficiência β-galactosilceramidase (β-Galsil) (EC 3.2.1.46), um defeito enzimático que causa uma neurodegenerativa relatório, hipertonia muscular e espasticidade, convulsões, perda auditiva e em 85% Dos casos de morte precoce, entre outros. A incidência da doença de Krabbe documentado para os Estados Unidos e na Europa é de 1:100.000 recém-nascidos, mas estudos recentes têm mostrado valores maiores do que cerca de 1:22.000, em Nova York. Na América Latina, os relatórios são escassos, com relatos de rastreio de alto risco no Brasil e casos isolados no México, proporcionando um cenário importante subdiagnóstico, a situação não é desconhecida em que a Colômbia, não há literatura Onde sobre a doença. Um estudo de atividade e valores de referência para a enzima β-galactosilceramidase leucocital, foi então apresentado comunidade científica, de 259 amostras de 110 indivíduos saudáveis e 149 pacientes com comprometimento neurodegenerativo. A avaliação enzimática envolveu dois métodos (Colorimétrico e Fluorométrico) que permitiram o estabelecimento de uma gama de referência para β-Galsil na técnica Colorimétrica: 2,04-14,93 nmol /mgprot/h e na técnica fluorométrica: 0,3-4,21nmol/mgprot/h. O estudo de triagem permitiu a identificação de um paciente com doença de Krabbe que apresentou valores de atividade expressados em nmol / mgprot / h de 1,85 e 0,034, correspondente ao das técnicas descritas acima. Uma conclusão final que valida os dois métodos padronizados para o diagnóstico da doença e estabelecer valores de referência na população colombiano.
Subject(s)
Humans , Leukodystrophy, Globoid Cell , Lysosomal Storage Diseases , Gangliosidosis, GM1 , ColombiaABSTRACT
Objective Establish a method for measuring the activities of Galactocerebrosidase (GALC), α-Glucosidase(GAA), α-Galactosidase (GLA) and α-L-Iduronidase (IDUA) in dried blood spots specimen by tandem mass spectrometry ( MS/MS ).Methods A total of 2175 dried blood spot samples forinborn errors of metabolism in neonatalscreening center of Shanghai Xinhua hospital were collected in July and November, 2013.And twenty dried blood spot samples from patients withlysosomalstorage disorders( LSDs) of Shanghai Xin Hua Hospital were collected from September 2012 to January 2014.The extraction of DBS was incubated with enzyme substrates and internal standards.After liquid-liquid and solid-phase extraction, the extraction solution was dried under nitrogen and reconstituted.Then enzyme reaction products and internal standards were analyzed by MS/MS.Linearity, precision, accuracy and the limit of detection were evaluated.2175 dried blood spot samples were detected to establish the normal reference range for the activities of four enzymes according to 0.5th to 99.5th percentiles.20 specimens from patients withLSDs were detected to verify the reference range inclinical judgment.Results The intraassay and interassay precisions ranged from 1.7%to 11.8%, and the intraassay and interassay accuracies ranged from 85%to 115%.The linear coefficients for measured concentration of enzyme products/internal standards and theoretical concentration were 0.997-0.999.The limits of detection forGALC, GAA, GLA and GLA were 0.03 μmol/(L· h), 0.09 μmol/(L· h), 0.12 μmol/(L· h) and 0.16 μmol/(L· h) .The normal reference values for GALC, GAA, GLA and GLAwere 0.51-8.51μmol( L· h) ,1.99-22.22μmol/( L· h),1.68-41.59 μmol/(L· h) and 2.36-19.21 μmol/(L· h).The enzymes of 20 patients with LSDs were remarkably decreased compared to the normal range.The Krabbe, Pompe, Fabry, MPSⅠpatients can be effectively detected by this MS/MS method.Conclusions A MS/MS method for measuring GALC, GAA, GLA and IDUA enzyme activities in DBShas been established.
ABSTRACT
Objective To investigate the clinical, biochemical and genetic features of a Chinese boy with early-onset glo-boid cell leukodystrophy (GLD). Methods The clinical and genetic data of a rare case of early-onset GLD were retrospectively analysed. Results At 2 months after birth, the boy showed progressive psychomotor regression. At 4 months of age when the boy was taken to a doctor, the pyramidal sign was positive. The cranial MRI showed that the body of the lateral cerebral ventri-cles was slightly enlarged and the brain ditch crack of frontal-temporal-parietal lobe was widened and deepened. On his brain CT scan, high signals in bilateral basal ganglia, thalami, cerebellar hemisphere were observed.β-galactosylceramidase (GALC) ac-tivity in the peripheral leucocytes was signiifcantly decreased (3.9 nmol/g protein.h). On his GALC gene, one homozygous novel mutation c.868C>T on exon 8 was found, which resulted in the amino acid change on p.R290C proteins. Conclutions Early-on-set GLD is a rare autosomal-recessive hereditary lysosomal storage disease with a terrible prognosis, in which beta-galactose glu-coside enzyme deifciency is induced by GALC gene mutation. The diagnosis of early-onset GLD is dififcult and should depend on enzyme assay and gene testing.
ABSTRACT
Krabbe disease (KD) or Globoid Cell Leukodystrophy (GLD) is a disorder involving the white matter of both the central and peripheral nervous systems. It is caused by congenital deficiency of a lysosomal enzyme, galactosylceramidase I, which is responsible for hydrolyzing the galactolipids in myelin. The disease is extremely rare occurring only one in 100,000 to one in 200,000 live births. The disease is classically of infantile origin but it can also occur in older children as well as adults. Adult variant is the rarest type. We hereby report a 34 year old male patient with progressively increasing ataxia, dysarthria. Typical MRI brain changes and diminished leucocyte galactocerebrosidase (GALC) enzyme levels clinched the diagnosis of Krabbe disease. There are very few cases of KD reported from India. This case report is to stress upon the fact that this rare entity should not be missed in an appropriate clinical setting.
ABSTRACT
Krabbe disease (globoid cell leukodystrophy) is an inherited recessive autosomal leukodystrophy caused by deficiency of the enzyme galactocerebrosidase. The lack of this enzyme leads to the build-up of galactolipids that will promote the death of oligodendrocytes and the demyelination of the central and peripheral nervous systems. There are two clinical forms: early onset and late onset. This article reports a case of late onset Krabbe disease and discusses the importance of early diagnosis for its prognosis.
Doença de Krabbe (leucodistrofia de células globoides) é uma leucodistrofia de herança autossômica recessiva causada pela deficiência da enzima galactocerebrosidase. A falta dessa enzima leva ao acúmulo de galactolipídeos que irão promover a morte dos oligodendrócitos e a desmielinização do sistema nervoso central e periférico. Possui duas formas clínicas: de início precoce e de aparecimento tardio. O presente artigo relata um caso da apresentação tardia da doença de Krabbe e discute a importância do diagnóstico precoce para o seu prognóstico.
Subject(s)
Humans , Galactolipids , Galactosylceramidase , Leukodystrophy, Globoid Cell , PsychosineABSTRACT
Objective To investigate the correlation of epidermal distribution of lamellar bodies and expression of ceramidase with skin barrier dysfunction in polymorphous light eruption.Methods Forty-seven patients with polymorphous light eruption and 40 healthy volunteers were recruited into this study.Noninvasive instruments were used to measure skin sebum content,transepidermal water loss(TEWL)and water content in stratum corneum in all of the subjects.Then,tissue specimens were obtained from the lesions at sunexposed sites in the patients and normal skin of the healthy volunteers.The ultrastructure and distribution of lamellar bodies were observed with transmission electron microscopy in five lesion and control specimens.Immunohistochemistry was performed to detect the expression of ceramidase in the tissue specimens.Results Compared with the normal skin from healthy volunteers,the lesions from patients showed decreased number of lamellar bodies in the granular layer and prick cell layer with a disorganized arrangement.Ceramidase was positively expressed in 20 lesion specimens and 36 normal control specimens,weakly expressed in 21 lesion specimens and 4 normal control specimens,and negative in 6 lesion specimens; there was a significant difference in the expression of ceramidase between the lesion specimens and normal control specimens(P ＜ 0.01).The lesions also showed high TEWL(34.2191 ± 12.70 vs.16.8350 ± 6.50,P ＜ 0.01),lower water content in stratum corneum(22.7319 ± 8.71 vs.29.4250 ± 5.08,P ＜ 0.01)and similar skin sebum content compared with the normal skin.Conclusions There is a disturbance in the synthesis of ceramide in patients with polymorphous light eruption,which may contribute to the impairment of skin barrier.