Browsing by Author "Kecmanovic, Miljana (36860979600)"

Charcot-Marie Tooth (CMT) is a clinically and genetically heterogeneous group of diseases with rough genotype-phenotype correlation, so the final diagnosis requires extensive clinical and electrophysiological examination, family data, and gene mutation analysis. Although there is a common pattern of genetic basis of CMT, there could be some population differences that should be taken into account to facilitate analyses. Here we present the algorithm for genetic testing in Serbian patients with demyelinating CMT, based on their genetic specificities: in cases of no PMP22 duplication, and if -X-linked CMT (CMTX) is not contraindicated by pattern of inheritance (male-to-male transmission), one should test for c.94A>G GJB founder mutation, first. Also, when a patient is of Romani ethnicity, or if there is an autosomal recessive inheritance in a family and unclear ethnicity, c.442C>T mutation in NDRG1 should be tested. © Copyright 2013, Mary Ann Liebert, Inc. 2013.

Background: Charcot-Marie-Tooth type 1A (CMT1A) is the most common type of hereditary motor and sensory neuropathies (HMSN), caused by the duplication of the 17p11.2 region that includes the PMP22 gene. Reciprocal deletion of the same region is the main cause of hereditary neuropathy with liability to pressure palsies (HNPP). CMT1A accounts for approximately 50% of HMSN patients. Diagnostics of CMT1A and HNPP are based on quantitative analysis of the affected region or RFLP detection of breakage points. The aim of this study was to improve the sensitivity and efficiency of CMT1A and HNPP genetic diagnostics by introducing analysis of six STR markers (D17S261-D17S122-D17S839-D17S1358-D17S955-D17S921) spanning the duplicated region. Methods: Forty-six CMT1A and seven HNPP patients, all genetically diagnosed by RFLP analysis, were tested for duplication or deletion using six STR markers. Results: In all CMT1A and HNPP patients, microsatellite analysis comprising six STR markers confirmed the existence of a duplication or deletion. In 89% (41/46) CMT1A patients the confirmation was based on detecting three alleles on at least one locus. In the remaining 11% (5) CMT1A patients, duplication was also confirmed based on two peaks with clear dosage difference for at least two different markers. All HNPP patients (7/7) displayed only one allele for each analyzed locus. Conclusions: Microsatellite analysis using six selected STR loci showed a high level of sensitivity and specificity for genetic diagnostics of CMT1A and HNPP. The results here strongly suggest STR marker analysis as a method of choice in PMP22 duplication/deletion testing. © 2016 by De Gruyter.

Background: Charcot-Marie-Tooth type 1A (CMT1A) is the most common type of hereditary motor and sensory neuropathies (HMSN), caused by the duplication of the 17p11.2 region that includes the PMP22 gene. Reciprocal deletion of the same region is the main cause of hereditary neuropathy with liability to pressure palsies (HNPP). CMT1A accounts for approximately 50% of HMSN patients. Diagnostics of CMT1A and HNPP are based on quantitative analysis of the affected region or RFLP detection of breakage points. The aim of this study was to improve the sensitivity and efficiency of CMT1A and HNPP genetic diagnostics by introducing analysis of six STR markers (D17S261-D17S122-D17S839-D17S1358-D17S955-D17S921) spanning the duplicated region. Methods: Forty-six CMT1A and seven HNPP patients, all genetically diagnosed by RFLP analysis, were tested for duplication or deletion using six STR markers. Results: In all CMT1A and HNPP patients, microsatellite analysis comprising six STR markers confirmed the existence of a duplication or deletion. In 89% (41/46) CMT1A patients the confirmation was based on detecting three alleles on at least one locus. In the remaining 11% (5) CMT1A patients, duplication was also confirmed based on two peaks with clear dosage difference for at least two different markers. All HNPP patients (7/7) displayed only one allele for each analyzed locus. Conclusions: Microsatellite analysis using six selected STR loci showed a high level of sensitivity and specificity for genetic diagnostics of CMT1A and HNPP. The results here strongly suggest STR marker analysis as a method of choice in PMP22 duplication/deletion testing. © 2016 by De Gruyter.

Purpose Oxidative stress is recognized as an important factor in progressive myoclonus epilepsy (PME). Genetic polymorphism of glutathione S-transferases (GSTs), which are involved in both protection from oxidative damage and detoxification, might alter the capacity for protecting tissues from exogenous and endogenous oxidants. We aimed to assess a possible association between GST polymorphism and PME, as well as, correlation between GST genotypes and oxidative phenotype in PME patients. Methods GSTA1, GSTM1, GSTP1 and GSTT1 genotypes were determined in 26 patients with PME and 66 controls. Byproducts of protein oxidative damage (thiol groups (P-SH) and nitrotyrosine), superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were determined. Results The frequency of GSTA1, GSTM1 and GSTP1 genotypes was not significantly different between PME patients and controls, while individuals with GSTT1-null genotype were at 5.44-fold higher risk of PME than carriers of GSTT1-active genotype. Moreover, significant risk of PME was obtained in carriers of both GSTT1-null and GSTM1-null genotypes. Carriers of combined GSTA1- active and GSTT1-null genotype were at highest, 7.55-fold increased risk of PME. Byproducts of protein damage did not reach statistical significance, while SOD and GPX activities were significantly higher in PME patients then in controls. When stratified according to GST genotype, P-SH groups were significantly lower only in patients with GSTT1-null genotype in comparison to carriers of active genotype. Only SOD activity was increased in GSTT1-null when compared to corresponding active genotype. Conclusions GSTT1-null genotype might be associated with the increased risk and enhanced susceptibility to oxidative stress in PME patients. © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Purpose Oxidative stress is recognized as an important factor in progressive myoclonus epilepsy (PME). Genetic polymorphism of glutathione S-transferases (GSTs), which are involved in both protection from oxidative damage and detoxification, might alter the capacity for protecting tissues from exogenous and endogenous oxidants. We aimed to assess a possible association between GST polymorphism and PME, as well as, correlation between GST genotypes and oxidative phenotype in PME patients. Methods GSTA1, GSTM1, GSTP1 and GSTT1 genotypes were determined in 26 patients with PME and 66 controls. Byproducts of protein oxidative damage (thiol groups (P-SH) and nitrotyrosine), superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were determined. Results The frequency of GSTA1, GSTM1 and GSTP1 genotypes was not significantly different between PME patients and controls, while individuals with GSTT1-null genotype were at 5.44-fold higher risk of PME than carriers of GSTT1-active genotype. Moreover, significant risk of PME was obtained in carriers of both GSTT1-null and GSTM1-null genotypes. Carriers of combined GSTA1- active and GSTT1-null genotype were at highest, 7.55-fold increased risk of PME. Byproducts of protein damage did not reach statistical significance, while SOD and GPX activities were significantly higher in PME patients then in controls. When stratified according to GST genotype, P-SH groups were significantly lower only in patients with GSTT1-null genotype in comparison to carriers of active genotype. Only SOD activity was increased in GSTT1-null when compared to corresponding active genotype. Conclusions GSTT1-null genotype might be associated with the increased risk and enhanced susceptibility to oxidative stress in PME patients. © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.