Home About us Contact
|
Home About us Contact | ||
|
|
||
Reductase Deficiency (reductase + deficiency)
Selected AbstractscblE type of homocystinuria due to methionine synthase reductase deficiency: functional correction by minigene expressionHUMAN MUTATION, Issue 6 2005Petra Zavadáková No abstract is available for this article. [source] Stable maintenance of 5, -reductase activity in long-term subcultures of fibroblasts derived from the foreskinINTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2002Kazumi Nakae Abstract Background: There is up to a 50-fold variation in control subjects in current assays of 5,-reductase activity which makes interpretation difficult. It was therefore attempted in this study to establish an assay method which produced stable 5,-reductase activity in long-term subcultured foreskin fibroblasts. Methods: Foreskin fibroblasts were obtained from three boys with phimosis (control subjects), three patients with Reifenstein syndrome and one patient with 5,-reductase deficiency (due to mutation L113P in exon 2 of the SRD5A2 gene). To maximize the number of cells in the DNA synthesis phase, cells were subcultured consistently to approximately 70% confluency. Thawed cells, frozen after the third subculture, were incubated for 24 h with [1,,2,- 3H] testosterone. 5,-Reductase activity was expressed as the sum of formed [3H] 5,-reduced metabolites (separated by thin-layer chromatography). Results: The full range of 5,-reductase activity in controls and patients with Reifenstein syndrome was 3.44,15.59 pmol/h per mg protein: a 4.53-fold variation. The activity in the patient with 5,- reductase deficiency was 0.52 pmol/h per mg protein. Conclusion: By the cell culture methods used in this study, which aimed to increase the number of cells in the DNA synthesis phase, foreskin fibroblasts maintained a considerably stable level of 5,-reductase activity during long-term subculture. Therefore, this assay method can be used for differential diagnosis of 5,-reductase deficiency from other relevant entities. [source] Determination of total homocysteine in dried blood spots using high performance liquid chromatography for homocystinuria newborn screeningPEDIATRICS INTERNATIONAL, Issue 1 2004Andi Dwi Bahagia Febriani AbstractBackground: The most widely used method for newborn screening for homocystinuria (HCU) is a semiquantitative bacterial inhibition assay for measuring methionine concentration in dried blood spots (DBS). Because this method has resulted in a number of missed cases due to many factors, we developed a high performance liquid chromatography (HPLC) method with fluorescence detection to measure total homocysteine (tHcy) in DBS which might be useful for newborn screening for HCU. Methods: One disk of DBS 3 mm in diameter was sonicated in 10 min. The extract was reduced with dithioerythritol and was derivatized with 4-aminosulfonyl-7fluoro-2,1,3-benzoxadiazole before injection into HPLC. Results: This method showed good linearity (r = 0.996), precision (coefficient of variation range 2.7,5%), and excellent correlation coefficient between DBS and serum tHcy, both in control (r = 0.932) and patient samples (r = 0.952). By this method, the mean tHcy concentration in DBS of preterm newborns, full-term newborns, and adults was 1.4 ± 1.0, 2.5 ± 1.6, and 4.9 ± 1.5 µmol/L, respectively. The mean tHcy DBS concentration in two cases of cystathionine-,-synthase deficiency and one case of 5,10-methylentetrahydrofolate reductase deficiency was 22.7 ± 2.88, 29.3 ± 1.90, and 41.3 µmol/L, respectively. Conclusions: The present method, which is rapid, user friendly and reliable, seems applicable to newborn screening of HCU in place of methionine measurement. [source] Evaluation of a fetus at risk for dihydropteridine reductase deficiency by direct mutation analysis using denaturing gradient gel electrophoresisPRENATAL DIAGNOSIS, Issue 10 2001H. Serap Kalkano Abstract Dihydropteridine reductase (DHPR) is an enzyme involved in the recycling of tetrahydrobiopterin (BH4), which is an obligate co-factor of the aromatic amino acid hydroxylases. DHPR deficiency is a rare, autosomal recessive disorder caused by mutations in the QDPR gene. DHPR-deficient patients are diagnosed by a lack of response to a low phenylalanine diet and by severe neurological symptoms. Final diagnosis is made by measurements of neurotransmitters and pterin metabolites in cerebrospinal fluid (CSF) and urine, in addition to DHPR enzyme activity, which can be assessed in whole red blood cells. Treatment of DHPR deficiency can be difficult and the outcome is not always satisfying, even if all treatment strategies are followed. Therefore prenatal diagnosis is of great importance in affected families. Prenatal diagnosis is possible by measuring DHPR activity in different cell types but this is time consuming. More than 25 different mutations have to date been identified in the QDPR gene and direct identification of a mutation in a fetus would be easy and rapid. We have developed a method based on denaturing gradient gel electrophoresis (DGGE) for the analysis of the QDPR gene. The method is useful for rapid and simultaneous scanning of all exons and flanking intronic sequences of the QDPR gene. We describe the first prenatal diagnosis conducted using this method. Copyright © 2001 John Wiley & Sons, Ltd. [source] ORIGINAL RESEARCH,INTERSEX AND GENDER IDENTITY DISORDERS: Gender Assignment and Medical History of Individuals with Different Forms of Intersexuality: Evaluation of Medical Records and the Patients' PerspectiveTHE JOURNAL OF SEXUAL MEDICINE, Issue 4i 2007Lisa Brinkmann PhD ABSTRACT Introduction., Until now, there are only few studies that focus on the specific treatment experiences of people with intersexuality and evaluate their outcome in terms of psychological, physical, and social well-being. Further, the presentation of the patients' perspective is often neglected in research. Aim., Overview of preliminary results of the Hamburg-Intersex-Study on gender assignment and medical history of adult subjects with intersexuality (disorders of sex development), as well as the patients retrospectively stated thoughts and feelings regarding these interventions. Main Outcome Measures., Medical records from participants of the study were analyzed. The subjective attitudes and evaluation of the treatment measures were assessed with a self-constructed questionnaire. Data on psychological well-being were measured with the Brief Symptom Inventory. Methods., In total, 37 adult participants (mean age 30.6 years) with following diagnosis were included: congenital adrenal hyperplasia, complete and partial androgen insensitivity syndrome, gonadal dysgenesis and disturbances of the androgen biosynthesis, such as 5 alpha reductase deficiency and 17 beta hydroxysteroid deficiency. Results., The majority of participants had (often multiple) genital surgery to correct the appearance of their genitalia and/or to enable sexual functioning. The diagnostic groups differ not only in amount and invasiveness of experienced surgical and medical treatment but also in the subjective and retrospective evaluation of the treatment measures and in the amount of reported psychological distress. Conclusion., Many subjects stated to have experienced the medical procedures and care very negatively, whereby the aspects of secrecy, untruthfulness, and concealment were stated as most difficult and burdening. Brinkmann L, Schuetzmann K, and Richter-Appelt H. Gender assignment and medical history of individuals with different forms of intersexuality: Evaluation of medical records and the patients' perspective. J Sex Med 2007;4:964,980. [source] Variants implicated in cortisone reductase deficiency do not contribute to susceptibility to common forms of polycystic ovary syndromeCLINICAL ENDOCRINOLOGY, Issue 1 2006Nicole Draper Summary Objective, There are close phenotypic similarities between cortisone reductase deficiency (CRD), a rare abnormality of cortisone metabolism, and polycystic ovary syndrome (PCOS). As there is evidence that CRD results from digenic mutations involving the genes encoding 11,-hydroxysteroid dehydrogenase type 1 (HSD11B1) and hexose-6-phosphate dehydrogenase (H6PD), we sought to establish whether CRD-associated variants in these genes, individually or in combination, influence susceptibility to PCOS. Design, Case-control, family-based association and quantitative-trait analyses. Patients, A UK case sample comprising 256 nuclear families ascertained from a PCOS offspring and 213 singleton PCOS cases plus 549 control subjects. Measurements, All subjects were genotyped for CRD-related variants in HSD11B1 (rs12086634) and H6PD (rs6688832). Testosterone was measured with an in-house radioimmunoassay using ether extraction and dextran-coated charcoal separation. Results, Case-control analyses revealed no differences in genotype distribution between PCOS and controls for rs12086634 or rs6688832 (both P = 0·84). Three per cent of cases and 2·4% of controls had genotype combinations (three or more variant alleles at the two sites) considered characteristic of CRD (P = 0·73). There were no departures from expectation in the family-based association studies, and no significant associations between genotypes (individually or in combination) and BMI, WHR or testosterone. Conclusions, The variants in HSD11B1 and H6PD typed, though implicated in causation of CRD, do not influence susceptibility to PCOS. It seems likely that additional variants within these genes are required for the development of CRD. [source] | |||||||||||||