Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q00604 (X-linked)
 16,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the methylation status of female germ cells in reference to the programmed reversal of X chromosome inactivation in these cells, we examined human fetal ovaries at developmental stages from the time germ cells initiate meiosis to when they cease to synthesize DNA (8-21 weeks gestation). Using methylation-sensitive restriction enzymes, we analyzed 57 MspI sites (32 sites in the CpG islands, and 25 nonclustered sites) from five X-linked housekeeping genes (HPRT, G6PD, P3, PGK, and GLA) and two tissue specific genes (X-linked F9 and autosomal EPO). Methylation patterns were compared to those of male germ cells, sperm, and somatic tissues of both sexes. All 32 MspI sites in CpG islands were unmethylated in germ-cell fractions of fetal ovary and adult testes, which could explain the reversibility of X inactivation in these tissues. However, whereas male meiotic germ cells were extensively methylated outside the islands (in the body of genes) and the methylation patterns resembled those of most somatic tissues, none of the 25 nonclustered CpGs was methylated in DNA contributed by the germ-cell component of fetal ovaries. The presence of faint MspI-like fragments in HpaII digests of fetal testes as well as fetal ovary prior to the onset of meiosis suggests that DNA of primordial germ cells is unmethylated in both sexes. Our observations of meiotic germ cells suggest that the female germ cells remain unmethylated, but that methylation in male germ cells occurs postnatally, prior to or during the early stages of spermatogenesis. In any event, the striking sex difference in methylation status of endogenous single-copy genes in meiotic germ cells could provide a molecular basis for parental imprinting of the mammalian genome.
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PMID:Sex difference in methylation of single-copy genes in human meiotic germ cells: implications for X chromosome inactivation, parental imprinting, and origin of CpG mutations. 169 9

Using a variety of genetic methods, it is shown in this paper that the genes GLA, G6PD, HPRT, and PGK are X-linked in the vole Microtus subarvalis. The order of these genes has been investigated in two vole species, M. subarvalis and M. kirgisorum, by using the mapping technique of Goss and Harris (1977a, b), which depends on the analysis of gamma-ray-induced gene segregation. The experimental data were processed with the computer programme RHMAP (Ginsburg et al., 1993). The analysis indicated that the correct gene order in M. subarvalis is PGK-HPRT-G6PD-GLA, and the same gene order was found to be the most probable for M. kirgisorum. The relative distances between the genes in the two vole species are apparently the same. The RHMAP programme has also been applied to data previously reported for the same set of X-linked genes in the American mink (Zhdanova et al., 1988), the Australian marsupial Planigale maculata (Dobrovic and Graves, 1986), and man. The evolutionary conservation of the linear order of these X-linked genes in different mammalian taxa is discussed.
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PMID:Demonstration of the X-linkage and order to the genes GLA, G6PD, HPRT, and PGK in two vole species of the genus Microtus. 825 99

The gene strQ was identified as the last gene of a putative transcription unit, strB1FGHPQ, located in the gene cluster for the production of 5'-hydroxy-streptomycin (OH-Sm) in Streptomyces glaucescens GLA.0. [In contrast, the corresponding operon in the str/sts-gene cluster of the Sm-producer Streptomyces griseus, strB1FGHIK, differs in the two distal genes; Mansouri, K. & Piepersberg, W. (1991) Mol. Gen. Genet. 228, 459-469]. The deduced StrQ protein exhibited similarities to members of the enzyme family of hexose-1-phosphate nucleotidylyltransferases (NDP-hexose synthases or pyrophosphorylases), with the strongest similarity to the subfamily of alpha-D-glucose-1-phosphate cytidylyltransferases (CDP-D-glucose synthases). The StrQ protein was heterologously expressed in Escherichia coli. The purified protein revealed an enzyme activity of that of a CDP-D-glucose synthase and a substrate specificity restricted to CTP and alpha-D-glucose 1-phosphate. The K(m) and Vmax values determined for CTP are 44 microM and 920 microM and for alpha-D-glucose 1-phosphate 195 microM and 1.06 mM, respectively. The CDP-D-glucose synthase activity was also detected in cells of S. glaucescens under the conditions of antibiotic production, but was absent from cells of the streptomycin producer S. griseus N2-3-11. Also, the genomes of several strains of S. griseus did not seem to possess strQ-related genes. In contrast, hybridisation experiments indicated that genes homologous to strQ were probably present in various other actinomycetes producing aminoglycosides. A possible function of the StrQ protein in the OH-Sm biosynthetic pathway of GLA.0 is discussed.
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PMID:The StrQ protein encoded in the gene cluster for 5'-hydroxystreptomycin of Streptomyces glaucescens GLA.0 is a alpha-D-glucose-1-phosphate cytidylyltransferase (CDP-D-glucose synthase). 999 Mar 25

Fabry disease (FD, OMIM 301500) is an X-linked inherited disorder of metabolism due to mutations in the gene encoding alpha-galactosidase A, a lysosomal enzyme. The enzymatic defect leads to the accumulation of neutral glycosphingolipids throughout the body, particularly within endothelial cells. Resulting narrowing and tortuosity of small blood vessels lead to tissue ischaemia and infarction. Inability to prevent the progression of glycosphingolipid deposition causes significant morbidity (acroparesthesia, angiokeratoma, autonomic dysfunction, cardiomyopathy and deafness), and mortality from early onset strokes, heart attack and renal failure in adulthood. Demonstration of alpha-galactosidase A deficiency in leukocytes or plasma is the definitive method for the diagnosis of affected hemizygous males. Most heterozygotes present with a cardiac, renal or neurological symptomatology, although to a lesser extent than what is observed in hemizygotes. Due to random X-chromosomal inactivation, enzymatic detection of carriers is often inconclusive. Molecular testing of possible carriers is therefore mandatory for accurate genetic counselling. The GLA gene has been cloned and more than 200 mutations have been identified. Medical management is symptomatic and consists of partial pain relief with analgesic drugs (gabapentin, carbamazepine), whereas renal transplantation or dialysis is available for patients experiencing end-stage renal failure. However, the ability to produce high doses of alpha-galactosidase A in vitro has opened the way to clinical studies and enzyme replacement therapy has recently been validated as a therapeutic agent for FD patients in clinical trials. Long term safety and efficacy of replacement therapy are currently being investigated.
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PMID:[Fabry's disease (alpha-galactosidase-A deficiency): physiopathology, clinical signs, and genetic aspects]. 1236 Jul 45

Fabry disease, an X-linked inborn error of glycosphingolipid catabolism, results from mutations in the gene encoding the lysosomal exoglycohydrolase, alpha-galactosidase A (alpha-Gal A; GLA). In two unrelated classically affected males, two alpha-Gal A missense mutations were identified: R112C + D313Y (c.334C>T + c.937G>T) and C172G + D313Y (c.514T>G + c.937G>T). The D313Y lesion was previously identified in classically affected males as the single mutation [Eng et al., 1993] or in cis with another missense mutation, D313Y + G411D (c.937G>T + c.1232G>A) [Guffon et al., 1998]. To determine whether the D313Y mutation was a deleterious mutation or a coding region sequence variant, the frequency of D313Y in normal X-chromosomes, as well as its enzymatic activity and subcellular localization in COS-7 cells was determined. D313Y occurred in 0.45% of 883 normal X-chromosomes, while the R112C, C172G, and G411D missense mutations were not detected in over 500 normal X-chromosomes. Expression of D313Y in COS-7 cells resulted in approximately 60% of wild-type enzymatic activity and showed lysosomal localization, while R112C, C172G, G411D, and the double-mutated constructs had markedly reduced or no detectable activity and were all retained in the endoplasmic reticulum. The expressed D313Y enzyme was stable at lysosomal pH (pH 4.6), while at neutral pH (pH 7.4), it had decreased activity. A molecular homology model of human alpha-Gal A, based on the X-ray crystal structure of chicken alpha-galactosidase B (alpha-Gal B; alpha-N-acetylgalactosaminidase) was generated [Garman et al., 2002], which provided evidence that D313Y did not markedly disrupt the alpha-Gal A enzyme structure. Thus, D313Y is a rare exonic variant with about 60% of wild-type activity in vitro and reduced activity at neutral pH, resulting in low plasma alpha-Gal A activity.
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PMID:Fabry disease: characterization of alpha-galactosidase A double mutations and the D313Y plasma enzyme pseudodeficiency allele. 1463 8

Fabry disease (FD, OMIM 301500) is an X-linked inborn error of metabolism due to mutations in the gene encoding a-galactosidase A, a lysosomal enzyme. FD is an X-linked disease and affected males are more severely affected than females. In Fabry disease, the penetrance and the severity index of the phenotype are high in males, while expressivity and severity index appears highly variable and often "intermediate" in heterozygous females. Classic definitions of X-linked recessive and dominant inheritance neither reflect the variable expressivity, nor take into account the multiple mechanisms that can lead to disease expression in heterozygous females. The use of the terms X-linked recessive and dominant should probably be abandoned, and Fabry disease simply described as following 'X-linked' inheritance. Due to random X-chromosomal inactivation, enzymatic detection of carriers is often inconclusive. Molecular testing of females at-risk to be carriers is therefore mandatory for accurate genetic counselling. The GLA gene has been cloned and more than 300 mutations have been identified. Most of them are private and have been identified in only one family
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PMID:[Genetics of Fabry disease: diagnostic and therapeutic implications]. 1754 62

Fabry disease is an inherited X-linked lysosomal storage disease due to a genetic defect of the GLA gene which encodes the protein of the enzyme alpha-galaktosidase A. Under normal concentrations this lysosomal enzyme is involved in degradation and catabolism processes of membrane glycosphingolipids in almost all cells of the human organism. The enzyme deficiency leads to a progressive accumulation of globotriaosylceramide (Gb3) in various tissues and organ systems and is responsible for the large variability of the clinical signs and symptoms of the disease. First signs and symptoms such as painful neuropathy (acroparethesia), hypo- or unhidrosis and gastrointestinal disturbances can be found already in childhood and mainly affect quality of life. In the following decades of life, renal cardiac, and cerebrovascular complications occur in hemizygous males and with some delay in a part of heterozygous females as well. If not treated, these complications result in increased morbidity and premature mortality. With the introduction of the enzyme replacement therapy (ERT) in 2001 a causal treatment is available. Published data from clinical trials and observational studies demonstrated that ERT mitigates signs and symptoms of the disease as well as quality of life, and has the potential to reduce mortality. The efficacy of ERT seems to be less pronounced in severe cases of the disease, which makes an early diagnosis and treatment more important in order to prevent or improve the progression of the disease.
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PMID:[Fabry disease. An interdisciplinary challenge]. 1794 Sep 33

Fabry disease is an under-recognized X-linked lysosomal disorder, due to alpha-galactosidase A deficiency. Most of the mutations in the GLA gene are detectable using genomic sequencing analysis. However, deletions of one or more exons or deletion encompassing the entire gene are undetectable, especially in heterozygous females. The Multiplex Ligation-dependent Probe Amplification (MLPA) is an efficient tool for discovering these rearrangements. In this study two novel different deletions were detected using MLPA assay on two Fabry patients, both resulted mutation negative by sequencing analysis. These data suggest that this screening should be systematically included in genetic testing surveys of patients with Fabry disease.
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PMID:Identification of GLA gene deletions in Fabry patients by Multiplex Ligation-dependent Probe Amplification (MLPA). 1847 90

Fabry disease (FD) is a rare X-linked lysosomal storage disorder resulting from the deficient activity of the enzyme alpha-galactosidase A. Angiokeratomas (AKs) are a frequent manifestation of this disease. They usually become apparent during childhood and can cause important cosmetic disability. Current treatment of this feature in the setting of FD has been mainly based on the application of laser systems, namely the argon laser, the variable pulse width 532-nm Nd:YAG laser, the 578-nm copper vapor laser and the flashlamp-pumped pulsed dye laser. We report the case of a 31-year-old Caucasian woman with a clinical and molecular (GLA p.R118C) diagnosis of FD, presenting multiple AKs scattered over the buttocks and thighs. She was treated with 10 sessions of intense pulsed light (IPL), with a 4-8-week interval between them. An almost complete clearance of the lesions was obtained, with no scars or significant complaints. No recurrence occurred during a 12-month follow-up period. The IPL source can be considered a suitable, effective and safe treatment modality for these cutaneous lesions that typically affect patients with FD, with no need for local anesthesia and with very satisfactory cosmetic results. To our best knowledge, there are no reports in the literature of Fabry's AKs treated with IPL.
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PMID:Angiokeratomas of Fabry successfully treated with intense pulsed light. 1883 Aug 71

Fabry's disease is an X-linked lysosomal storage disorder caused by abnormalities in the GLA gene, which leads to a deficiency in alpha-galactosidase A. The consequent abnormal accumulation of glycosphingolipids results in several clinical signs and symptoms and substantial morbidity and mortality. This review covers all basic aspects of the disease such as epidemiology, pathophysiology, clinical presentation by systems, diagnosis, management, prevention, and repercussions on quality of life. With the development of enzyme replacement therapy in the past few years, early initiation of treatment is key for improvement in major affected organs with decreased cardiac mass and stabilisation of kidney function, and improvement in neuropathic pain, sweating, gastrointestinal symptoms, hearing loss, and pulmonary symptoms. However, treatment of individual symptoms in addition to enzyme replacement therapy seems to be needed for many patients, especially those who have had some degree of organ dysfunction. Additional data are needed to document long-term treatment outcomes.
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PMID:Fabry's disease. 1894 Apr 66


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