Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
3.
J Inherit Metab Dis ; 33 Suppl 3: S113-21, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20151204

RESUMO

Fructose 1,6-bisphosphatase (FBPase) deficiency is an inborn error of metabolism in the gluconeogenetic pathway. During periods of low food intake or infections, a defect in FBPase can result in hypoglycemia, ketonuria and metabolic acidosis. We established a diagnostic system for FBPase deficiency consisting of enzyme activity measurement and mutation detection in calcitriol-stimulated monocytes. In healthy individuals, we showed that FBPase activity is present in monocytes but not in other leukocytes. We describe the clinical course of four individuals from two Swedish families with FBPase deficiency. Family 1: patient 1 died at the age of 6 months after a severe episode with hypoglycemia and acidosis; patients 2 and 3 were followed for >30 years and were found to have a very favorable long-term prognosis. Their FBPase activity from jejunum (residual activity 15-25% of healthy controls), mixed leukocytes (low or normal levels), and calcitriol-stimulated monocytes (no detectable activity) was compared. Mutation analysis showed they were heterozygous for two genetic alterations (c.778G>A; c.881G>A), predicting amino acid exchanges at position p.G260R and p.G294E, originating from their parents. Family 2: patient 4 had no detectable levels of FBPase in stimulated monocytes. A mutation (c.648C>G) predicting a premature stop codon at position p.Y216X was found in one allele and a large deletion of about 300 kb, where the genes FBP2, FBP1 and a part of ONPEP are located, in the other. In conclusion, we present a reliable diagnostic system to verify an FBPase deficiency and find the genetic aberration.


Assuntos
Calcitriol , Deficiência de Frutose-1,6-Difosfatase/diagnóstico , Frutose-Bifosfatase/genética , Jejuno/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Mutação , Adulto , Células Cultivadas , Criança , Pré-Escolar , Análise Mutacional de DNA , Evolução Fatal , Feminino , Deficiência de Frutose-1,6-Difosfatase/enzimologia , Deficiência de Frutose-1,6-Difosfatase/genética , Deficiência de Frutose-1,6-Difosfatase/terapia , Frutose-Bifosfatase/metabolismo , Predisposição Genética para Doença , Testes Genéticos , Hereditariedade , Heterozigoto , Humanos , Lactente , Jejuno/enzimologia , Masculino , Monócitos/enzimologia , Linhagem , Fenótipo , Valor Preditivo dos Testes , Prognóstico , Fatores de Tempo
5.
Eur J Hum Genet ; 12(6): 424-32, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15026783

RESUMO

Four unrelated patients with glyceroluria ranging from 7 to 170 mmol/l were studied. The activity of glycerol kinase (GK) in cultured fibroblasts was determined with a specific enzyme assay and with two indirect methods, that is, incorporation into macromolecules of [(14)C] from [(14)C]glycerol and its oxidation to [(14)C]CO(2). Exon amplification and RT-PCR were used to identify mutations. In patient 1, with low activity in all three assays, we identified a c.1194A>C (E398D) missense mutation. In patient 2 with a considerable activity of the GK enzyme (22% of reference), oxidation to [(14)C]CO(2) (37%) and a high incorporation of [(14)C] into macromolecules (92%), we identified a c.182T>C (L61P) mutation that causes the enzyme to have a higher K(m) for glycerol ( approximately 300 microM) than normals (2-8 microM). In patient 3, the GK activity estimated by the three different methods ranged from 16 to 22% of reference. Analysis of mRNA from the GK gene revealed three alternatively spliced transcripts. A mutation in intron 3 (g.16835G>A) resulted in an insertion of a cryptic exon between exon 2 or 3 and exon 4. Patient 4 with minor glyceroluria (7 mmol/l) and normal plasma glycerol concentration had normal activity with all three assay methods, thus excluding GK deficiency (GKD) as a cause of slight glyceroluria. To evaluate fully patients with glyceroluria, one needs to measure the GK activity and relate this and the clinical data to genetic findings. Residual enzyme activities in cultured fibroblasts can be found in GKD patients with severe clinical symptoms.


Assuntos
Processamento Alternativo , Glicerol Quinase/deficiência , Glicerol Quinase/genética , Mutação/genética , Transcrição Gênica , Sequência de Aminoácidos , Criança , Pré-Escolar , Éxons/genética , Fibroblastos/enzimologia , Glicerol/metabolismo , Glicerol Quinase/química , Humanos , Recém-Nascido , Íntrons/genética , Masculino , Dados de Sequência Molecular , Conformação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
6.
Mol Genet Metab ; 79(3): 149-59, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12855219

RESUMO

Five cases of glycerol kinase deficiency are presented with clinical, biochemical, and genetic results. Two had the glycerol kinase deficiency as part of an Xp21 contiguous gene deletion syndrome-complex form-and three had an isolated form of the enzyme deficiency. In these we found two splice site mutations (IVS1+4A>G, IVS9-1G>T) and one insertion (1393_1394insG). In patients with the complex form, a deletion of the DAX1, GK genes and the distal part of the DMD gene was found. A computerized study was performed to predict the effects of the splice site mutations. It showed that the IVS9-1G>T mutation substantially altered and removed the wild-type site and enhanced a cryptic site seven nucleotides downstream, and that the IVS1+4A>G diminished the strength of the wild-type donor site from strong to leaky. To verify these predictions, we developed an RT-PCR system with gene-specific primers that exclusively amplifies the Xp21 glycerol kinase gene transcript. Identification of individuals at risk is motivated by a need to avoid delay in a correct diagnosis. For reliable identification of heterozygotes for isolated glycerol kinase deficiency, knowledge of the specific mutation in the proband is required. This is easily obtained with the RT-PCR analyses developed in this study.


Assuntos
Análise Mutacional de DNA , Glicerol Quinase , Glicerol Quinase/genética , Insuficiência Adrenal/genética , Cromossomos Humanos X , Receptor Nuclear Órfão DAX-1 , Primers do DNA/química , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Deleção de Genes , Glicerol/sangue , Glicerol/urina , Glicerol Quinase/química , Glicerol Quinase/deficiência , Humanos , Recém-Nascido , Masculino , Dados de Sequência Molecular , Distrofia Muscular de Duchenne/genética , Mutação , Polônia , Polimorfismo Conformacional de Fita Simples , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores do Ácido Retinoico/química , Receptores do Ácido Retinoico/deficiência , Receptores do Ácido Retinoico/genética , Proteínas Repressoras/química , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
7.
Clin Chem Lab Med ; 41(1): 46-55, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12636049

RESUMO

Recent recommendations in the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (ATPIII) are expected to increase the number of triglyceride (TG) determinations and consequently the risk of misinterpretation of "non-blanked" results with co-determination of free glycerol. Glycerol-kinase deficiency (GKD) is one cause of falsely elevated TG results. The natural history of isolated GKD with symptom-free cases and cases with e.g. severe episodes of hypoglycemia and/or ketoacidosis challenges the laboratories to identify cases of GKD and family members at risk. "Blanked" methods reporting both glycerol and TG concentration are therefore desirable. Molecular studies of the glycerol kinase (GK) and DAX1 genes were performed on four cases of "persistent hypertriglyceridemia" found in an Italian population and on two pediatric cases with high serum glycerol concentration. Two new missense mutations were found (C358Y, T961). Molecular modeling on GK from E. coli, indicate that these mutations are located in parts of the enzyme important for enzyme formation or activity. One splice-site mutation, (IVS9A-1G>A), was found in two brothers. Splice-junction analysis indicates that it destroys the splice site and results in a mixture of mRNA. Deletion of the GK and DAX1 genes was found in one child with symptoms of adrenal failure. A female with glycerolemia and glyceroluria had normal GK activity but possibly slightly decreased ability to oxidize glycerol.


Assuntos
Proteínas de Ligação a DNA/genética , Heterogeneidade Genética , Glicerol Quinase/genética , Glicerol/metabolismo , Hipertrigliceridemia/genética , Receptores do Ácido Retinoico/genética , Proteínas Repressoras , Fatores de Transcrição/genética , Triglicerídeos/metabolismo , Doenças das Glândulas Suprarrenais/genética , Alelos , Processamento Alternativo , Sequência de Aminoácidos , Criança , Pré-Escolar , Receptor Nuclear Órfão DAX-1 , Primers do DNA/química , Feminino , Glicerol Quinase/deficiência , Humanos , Hipertrigliceridemia/enzimologia , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Deleção de Sequência , Homologia de Sequência de Aminoácidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA