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Deficient Activity (deficient + activity)
Selected AbstractsFabry disease: overall effects of agalsidase alfa treatmentEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2004M. Beck Abstract Background, Fabry disease is a rare X-linked disorder caused by deficient activity of the lysosomal enzyme ,-galactosidase A. Progressive accumulation of the substrate globotriaosylceramide in cells throughout the body leads to major organ failure and premature death. The Fabry Outcome Survey (FOS) is a European outcomes database which was established to collect data on the natural history of this little-known disease and to monitor the long-term efficacy and safety of enzyme replacement therapy (ERT) with agalsidase alfa. This paper presents the first analysis of the FOS database on the effects of ERT on renal function, heart size, pain and quality of life. Design, The effects of 1 and 2 years of ERT with agalsidase alfa on renal function (assessed by estimated glomerular filtration rate), heart size (assessed by echocardiography), pain (assessed by the Brief Pain Inventory) and quality of life (assessed by the European Quality of Life Questionnaire EQ-5D) were analyzed in a cohort of 545 patients, 314 of whom were receiving treatment (188 for at least 12 months and 92 for at least 24 months; mean duration of treatment, 17 months; maximum duration, 56 months). Results, Treatment with agalsidase alfa stabilized renal function in patients with a mild or moderate deterioration in renal function at baseline, reduced left ventricular size in patients who had an enlarged heart at baseline, and improved pain scores and quality of life. These improvements were similar in hemizygous men and heterozygous women with Fabry disease. Conclusions, Enzyme replacement therapy with agalsidase alfa leads to significant clinical benefits in patients with Fabry disease, and treatment is likely to alter the natural history of this disorder. [source] Mutational spectrum and genotype,phenotype correlations in mevalonate kinase deficiency,HUMAN MUTATION, Issue 8 2006Saskia H.L. Mandey Abstract Mevalonate kinase deficiency (MKD) is an autosomal recessive autoinflammatory disorder caused by mutations in the MVK gene resulting in deficient activity of mevalonate kinase (MK). Depending on the clinical severity, MKD may present as hyper-IgD and periodic fever syndrome (HIDS) or the more severe mevalonic aciduria (MA). We analyzed the MVK gene in 57 patients with MKD and found 39 different mutations including 15 novel mutations, expanding the total mutational spectrum of MKD to 63 mutations. To get more insight into the genotype,phenotype correlation in MKD, we studied the effect of selected missense mutations on MK protein stability and activity in various patient fibroblast cell lines. All MKD cell lines showed markedly decreased MK activities that correlated well with the clinical severity and, for most of the cell lines, with the amount of MK protein. When fibroblasts of MKD patients were cultured under conditions known to promote a more controlled protein folding, all cell lines of patients with the HIDS phenotype and few cell lines of patients with the MA phenotype showed an increase in the residual MK activity. This increase in enzyme activity correlates well with an increase in the MK protein levels in these cell lines, indicating that most of the mutations in MKD affect stability and/or folding of the MK protein rather than affecting the catalytic properties of the enzyme. The finding that the residual activity in MKD can be manipulated by environmental conditions may offer therapeutic options to alleviate or prevent the clinical symptoms associated with MKD. Hum Mutat 27(8), 796,802, 2006. © 2006 Wiley-Liss, Inc. [source] Novel mutations in the 7-dehydrocholesterol reductase gene of 13 patients with Smith,Lemli,Opitz syndromeANNALS OF HUMAN GENETICS, Issue 3 2001P. E. JIRA Smith,Lemli,Opitz syndrome (SLOS) is caused by mutations in the DHCR7 gene leading to deficient activity of 7-dehydrocholesterol reductase (DHCR7; EC 1.3.1.21), the final enzyme of the cholesterol biosynthetic pathway, resulting in low cholesterol and high concentrations of its direct precursor 7-dehydrocholesterol in plasma and tissues. We here report mutations identified in the DHCR7 gene of 13 children diagnosed with SLOS by clinical and biochemical criteria. We found a high frequency of the previously described IVS8,1 G > C splice acceptor site mutation (two homozygotes, eight compound heterozygotes). In addition, 13 missense mutations and one splice acceptor mutation were detected in eleven patients with a mild to moderate SLOS-phenotype. The mutations include three novel missense mutations (W182L, C183Y, F255L) and one novel splice acceptor site mutation (IVS8,1 G > T). Two patients, homozygous for the IVS8,1 G > C mutation, presented with a severe clinical phenotype and died shortly after birth. Seven patients with a mild to moderate SLOS-phenotype disclosed compound heterozygosity of the IVS8,1 G > C mutation in combination with different novel and known missense mutations. [source] Molecular and clinical consequences of novel mutations in the arylsulfatase A geneCLINICAL GENETICS, Issue 1 2009ugowska Metachromatic leukodystrophy (MLD), a severe neurodegenerative metabolic disorder, is caused by deficient activity of arylsulfatase A (ARSA; EC 3.1.6.8), which leads to a progressive demyelinating process in central and peripheral nervous systems. In this study, a DNA sequence analysis was performed on six Polish patients with different types of MLD. Six novel mutations were identified: one nonsense (p.R114X), three missense (p.G122C, p.G293C, p.C493F) and two frameshift mutations (g.445_446dupG and g.2590_2591dupC). Substitutions p.G293C and p.C493F and duplication g.445_446dupG caused a severe reduction of enzyme activity in transient transfection experiments on mammalian cells (less than 1% of wild-type (WT) ARSA activity). Duplication 2590_2591dupC preserved low-residual ARSA activity (10% of WT ARSA). In summary, the novel MLD-causing mutations in the exons 2, 5 and even in 8 of the ARSA gene described here can be classified as severe type 0, leading in homozygosity to the late infantile form MLD. Growth retardation, delayed motor development, gait disturbances, tonic,clonic seizures and non-epileptic muscle spasms were the first onset symptoms in patients with late infantile form of MLD. In individual with juvenile type MLD gait disturbances evidenced the onset of the disease, while in a patient with late juvenile MLD, difficulties at school were displayed. [source] The Mainz Severity Score Index: a new instrument for quantifying the Anderson,Fabry disease phenotype, and the response of patients to enzyme replacement therapyCLINICAL GENETICS, Issue 4 2004C Whybra Anderson,Fabry disease (AFD) is an X-linked disorder caused by deficient activity of the lysosomal enzyme ,-galactosidase A. The availability of enzyme replacement therapy (ERT) for this debilitating condition has led to the need for a convenient and sensitive instrument to monitor clinical effects in an individual patient. This study aimed to develop a scoring system , the Mainz Severity Score Index (MSSI) , to measure the severity of AFD and to monitor the clinical course of the disease in response to ERT. Thirty-nine patients (24 males and 15 females) with AFD were assessed using the MSSI immediately before and 1 year after commencing agalsidase alfa ERT. Control data were obtained from 23 patients in whom AFD was excluded. The MSSI of patients with AFD was significantly higher than that of patients with other severe debilitating diseases. The MSSI indicated that, although more men than women had symptoms classified as severe, overall, the median total severity scores were not significantly different between male and female patients. One year of ERT with agalsidase alfa led, in all patients, to a significant (p < 0.001) reduction in MSSI score (by a median of nine points). This study has shown that the MSSI score may be a useful, specific measure for objectively assessing the severity of AFD and for monitoring ERT-related treatment effects. [source] Identification of four novel mutations in five unrelated Korean families with Fabry diseaseCLINICAL GENETICS, Issue 3 2000J-K Lee Fabry disease is a X-linked recessively inherited metabolic disorder, which results from the deficient activity of the lysosomal hydrolase ,-galactosidase A leading to the systemic deposition of glycosphingolipids with terminal ,-galactosyl moieties. Single-strand conformation polymorphism (SSCP) analysis was performed, followed by DNA sequencing of PCR amplified exons of the human ,-galactosidase A gene in 5 unrelated Korean patients with classic Fabry disease. Five different mutations were identified; two nonsense mutations (Y86X and R342X), one missense mutation (D266N), and two small deletions (296del2 and 802del4). Except for R342X mutation, four were novel mutations (Y86X, D266N, 296del2, 802del4). A T to G transversion at nucleotide position 5157 in exon 2 caused a tyrosine-to-stop substitution at codon 86. A G to A transition at position 10 287 in exon 5 substituted an asparagine for an aspartate at codon 266. Mutation 296del2 in exon 2 resulted in a frame shift with a stop signal at the 22th codon downstream from the mutation, whereas mutation 802del4 resulted in a stop codon at the site of 4 bp deletion. In addition, the 802del4 was found to be a de novo mutation. This is the first report on mutation analysis of the human ,-galactosidase A gene in Korean patients with Fabry disease. [source] Endothelial markers and homocysteine in patients with classic Fabry diseaseACTA PAEDIATRICA, Issue 2002K Demuth Aim: Fabry disease is an X-linked inborn error of glycosphingolipid metabolism due to the deficient activity of ,-galactosidase A, a lysosomal enzyme. It is a multisystem disorder characterized by progressive renal insufficiency, with added morbidity from cardio- and cerebrovascular involvement. The recent availability of genetically engineered enzyme offers an effective targeted treatment approach, but also emphasizes the need for surrogate markers to delineate organ damage and monitor the efficacy of enzyme replacement therapy (ERT). Methods: Multiple endothelial factors and plasma homocysteine concentrations were investigated in 12 consecutive hemizygous males with classic Fabry disease and 15 controls as part of an exhaustive baseline evaluation prior to ERT. Results: Compared with the controls, plasma concentrations of homocysteine were significantly (p > 0.01) higher in patients with Fabry disease in the absence of chronic renal failure or vitamin deficiency. Plasma concentrations of vascular cell adhesion molecule-1 were also significantly (p > 0.05) higher in the patients, and there was a trend for decreased endothelin-1 levels. No difference was found in serum intercellular adhesion molecule-1, plasma P-selectin, serum E-selectin and plasma thrombomodulin between the patients and controls. Conclusions: The results do not reveal measurable evidence for endothelial and leukocyte activation that could reliably serve as surrogate markers for routine monitoring of the efficacy of ERT in patients with Fabry disease. While the exact origin and clinical significance of hyperhomocysteinaemia in Fabry disease remains to be studied in a larger cohort of patients carefully monitored for their concurrent medications, especially carbamazepine, we suggest that patients may benefit from folic acid or multivitamin therapy to treat this additional vascular risk factor, when present. [source] | |||||||||||||