Browsing by Author "Dobričić, Valerija (22952783800)"

Background/Aim. Duchenne muscular dystrophy (DMD) and its allelic form Becker muscular dystrophy (BMD) are X-linked diseases that affect males, characterized by progressive muscle and cardiopulmonary weakness, especially in DMD as a severe form of the disease. They result from mutations in the dystrophin gene, and the most common changes are large intragenic deletions and duplications (80%). One third of patients have de novo mutation and 2/3 of the mothers are estimated as carriers. The aim of the study was to analyze the frequency of duplications versus deletions in the dystrophin gene in patients with dystrophinopathies, as well as to analyze the phenotypic effect of large mutations obtained and to determine the carrier status of female relatives in probands with duplications. Methods. We examined 22 DMD and 35 BMD unrelated patients and 6 female relatives of the probands where duplications were found. We used polymerase chain reaction (PCR) and multiplex ligation-dependent probe amplification (MLPA) methods, according to the protocol, to detect or confirm mutations in probands and female carriers. Results. In probands, there were 34 (59.6%) large deletions (mostly affected exons 44–60) and 6 (10.5%) large duplications in 4 DMD and 2 BMD patients. Also, duplications were found in 3 out of 4 (75%) tested mothers. The distribution of duplications was heterogeneous, affecting N-terminal and central rod domain, and included more exons, except for one DMD patient who had duplication of exon 2. An exception from the Monaco rule was present in 9.5% of DMD and 15.8% of BMD probands, i.e. in 12.5% of DMD/BMD cases. Conclusion. In 57 DMD/BMD probands, we found 59.6% of large deletions and 10.5% of large duplications. The most affected region of the DMD gene was the central rod domain. An exception to Monaco's rule was present in 12.5% of DMD/BMD cases. Three out of 4 examined proband's mothers were confirmed as carriers. © 2020 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.

Background: Recent studies explored polymorphisms of multiple genes as contributing to genetic susceptibility to psychosis in Parkinson's disease (PDP). Objective: We aimed to examine the association of seven selected polymorphisms of genes related to dopamine pathways with PDP development. At the same time, demographic and clinical correlates of PDP were assessed. Methods: PD patients (n = 234), treated with levodopa for at least two years, were genotyped for the rs4680 in COMT, rs6277, rs1076560, and rs2283265 in DRD2, and rs1800497 and rs2734849 polymorphisms in ANKK1 genes. Also, variable number of tandem repeats polymorphism in the DAT gene was examined. Each patient underwent comprehensive neurological examination, assessment of psychosis, as defined by the NINDS/NIMH criteria, as well as screening of depression, anxiety, and cognitive status. Results: Diagnostic criteria for PDP were met by 101 (43.2%) patients. They had longer disease duration, were taking higher doses of dopaminergic agents, and had higher scores of the motor and non-motor scales than the non-PDP group. Multivariate regression analysis revealed LEDD≥900 mg, Unified Parkinson's Disease Rating Scale III part score, the Hamilton Depression Rating Scale score≥7, the Hamilton Anxiety Rating Scale score > 14,and GG homozygotes of rs2734849 ANKK1 as independent predictors of the onset of PDP. Conclusion: Besides previous exposure to dopaminergic drugs, impairment of motor status, depression and anxiety, as well-established clinical risk factors for the development of PDP, GG rs2734849 ANKK1 could also be a contributing factor, which requires addressing by future longitudinal studies. © 2021 - IOS Press. All rights reserved.

Background: Recent studies explored polymorphisms of multiple genes as contributing to genetic susceptibility to psychosis in Parkinson's disease (PDP). Objective: We aimed to examine the association of seven selected polymorphisms of genes related to dopamine pathways with PDP development. At the same time, demographic and clinical correlates of PDP were assessed. Methods: PD patients (n = 234), treated with levodopa for at least two years, were genotyped for the rs4680 in COMT, rs6277, rs1076560, and rs2283265 in DRD2, and rs1800497 and rs2734849 polymorphisms in ANKK1 genes. Also, variable number of tandem repeats polymorphism in the DAT gene was examined. Each patient underwent comprehensive neurological examination, assessment of psychosis, as defined by the NINDS/NIMH criteria, as well as screening of depression, anxiety, and cognitive status. Results: Diagnostic criteria for PDP were met by 101 (43.2%) patients. They had longer disease duration, were taking higher doses of dopaminergic agents, and had higher scores of the motor and non-motor scales than the non-PDP group. Multivariate regression analysis revealed LEDD≥900 mg, Unified Parkinson's Disease Rating Scale III part score, the Hamilton Depression Rating Scale score≥7, the Hamilton Anxiety Rating Scale score > 14,and GG homozygotes of rs2734849 ANKK1 as independent predictors of the onset of PDP. Conclusion: Besides previous exposure to dopaminergic drugs, impairment of motor status, depression and anxiety, as well-established clinical risk factors for the development of PDP, GG rs2734849 ANKK1 could also be a contributing factor, which requires addressing by future longitudinal studies. © 2021 - IOS Press. All rights reserved.

Background: Mutations in GNAL (DYT25) have recently been established as the first confirmed cause of focal or segmental adult-onset dystonia. Mutation carriers show craniocervical involvement; however, the GNAL mutational and phenotypic spectrum remain to be further characterized, and guidelines for diagnostic testing need to be established. Methods: The authors used Sanger sequencing to test for changes in the GNAL coding or splice-site regions in 236 Serbian patients suffering from isolated dystonia with craniocervical involvement. Results: One novel likely pathogenic substitution (c.1061T>C; p.Val354Ala) in GNAL was detected in a sporadic cervical dystonia patient (mutation frequency: 0.4%). This mutation was not present in the DNA of either parent, despite confirmed parentage. Conclusions: This is the first report of a de novo GNAL mutation causing genetically proven, seemingly sporadic DYT25 dystonia. Our finding highlights the importance of genetic testing for GNAL mutations in establishing the molecular diagnosis even for patients with a negative family history. © 2014 International Parkinson and Movement Disorder Society.

Background: Mutations in GNAL (DYT25) have recently been established as the first confirmed cause of focal or segmental adult-onset dystonia. Mutation carriers show craniocervical involvement; however, the GNAL mutational and phenotypic spectrum remain to be further characterized, and guidelines for diagnostic testing need to be established. Methods: The authors used Sanger sequencing to test for changes in the GNAL coding or splice-site regions in 236 Serbian patients suffering from isolated dystonia with craniocervical involvement. Results: One novel likely pathogenic substitution (c.1061T>C; p.Val354Ala) in GNAL was detected in a sporadic cervical dystonia patient (mutation frequency: 0.4%). This mutation was not present in the DNA of either parent, despite confirmed parentage. Conclusions: This is the first report of a de novo GNAL mutation causing genetically proven, seemingly sporadic DYT25 dystonia. Our finding highlights the importance of genetic testing for GNAL mutations in establishing the molecular diagnosis even for patients with a negative family history. © 2014 International Parkinson and Movement Disorder Society.

In this study we report clinical and imaging data from a multigenerational Serbian family with idiopathic basal ganglia calcification (IBGC) and exclusion of linkage to chromosome 14q, 2q37 and 8p21.1-q11.23. Fourteen out of 18 family members were personally examined and 11 of them were scanned with computed tomography (CT). CT scans revealed existence of symmetrical calcifications in six family members from three generations (four symptomatic and two asymptomatic). Age at onset of clinical symptoms varied between 22.0 and 55.4 years. The main clinical findings included parkinsonism, severe gait disturbances with freezing of gait, and dyskinesia. Hyperechogenicities identified by transcranial sonography corresponded well to the CT images of hyperintense calcifications in the same structures, whereas brain perfusion single photon emission computed tomography demonstrated predominant hypoperfusion in the frontal cortex and the basal ganglia. After exclusion of linkage to known loci, our pedigree with IBGC further demonstrates locus heterogeneity in this disorder. Analysis of clinically affected individuals supports observation that the clinical features of IBGC appear to be varied both within and between families. The age at onset of the clinical symptoms appeared to be decreasing in two observed transmissions, suggestive of possible genetic anticipation. © 2011 Springer-Verlag.

In this study we report clinical and imaging data from a multigenerational Serbian family with idiopathic basal ganglia calcification (IBGC) and exclusion of linkage to chromosome 14q, 2q37 and 8p21.1-q11.23. Fourteen out of 18 family members were personally examined and 11 of them were scanned with computed tomography (CT). CT scans revealed existence of symmetrical calcifications in six family members from three generations (four symptomatic and two asymptomatic). Age at onset of clinical symptoms varied between 22.0 and 55.4 years. The main clinical findings included parkinsonism, severe gait disturbances with freezing of gait, and dyskinesia. Hyperechogenicities identified by transcranial sonography corresponded well to the CT images of hyperintense calcifications in the same structures, whereas brain perfusion single photon emission computed tomography demonstrated predominant hypoperfusion in the frontal cortex and the basal ganglia. After exclusion of linkage to known loci, our pedigree with IBGC further demonstrates locus heterogeneity in this disorder. Analysis of clinically affected individuals supports observation that the clinical features of IBGC appear to be varied both within and between families. The age at onset of the clinical symptoms appeared to be decreasing in two observed transmissions, suggestive of possible genetic anticipation. © 2011 Springer-Verlag.

Most of the heritability in frontotemporal dementia (FTD) is accounted for by autosomal dominant hexanucleotide expansion in the chromosome 9 open reading frame 72 (C9orf72), pathogenic/likely pathogenic variants in progranulin (GRN), and microtubule-associated protein tau (MAPT) genes. Until now, there has been no systematic analysis of these genes in the Serbian population. Herein, we assessed the frequency of the C9orf72 expansion, pathogenic/likely pathogenic variants in GRN and MAPT in a well-characterized group of 472 subjects (FTD, Alzheimer’s disease - AD, mild cognitive impairment - MCI, and unspecified dementia - UnD), recruited in the Memory Center, Neurology Clinic, University Clinical Center of Serbia. The C9orf72 repeat expansion was detected in 6.98% of FTD cases (13.46% familial; 2.6% sporadic). In the UnD subgroup, C9orf72 repeat expansions were detected in 4.08% (8% familial) individuals. Pathogenic variants in the GRN were found in 2.85% of familial FTD cases. Interestingly, no MAPT pathogenic/likely pathogenic variants were detected, suggesting possible geographical specificity. Our findings highlight the importance of wider implementation of genetic testing in neurological and psychiatric practice managing patients with cognitive-behavioral and motor symptoms. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

Most of the heritability in frontotemporal dementia (FTD) is accounted for by autosomal dominant hexanucleotide expansion in the chromosome 9 open reading frame 72 (C9orf72), pathogenic/likely pathogenic variants in progranulin (GRN), and microtubule-associated protein tau (MAPT) genes. Until now, there has been no systematic analysis of these genes in the Serbian population. Herein, we assessed the frequency of the C9orf72 expansion, pathogenic/likely pathogenic variants in GRN and MAPT in a well-characterized group of 472 subjects (FTD, Alzheimer’s disease - AD, mild cognitive impairment - MCI, and unspecified dementia - UnD), recruited in the Memory Center, Neurology Clinic, University Clinical Center of Serbia. The C9orf72 repeat expansion was detected in 6.98% of FTD cases (13.46% familial; 2.6% sporadic). In the UnD subgroup, C9orf72 repeat expansions were detected in 4.08% (8% familial) individuals. Pathogenic variants in the GRN were found in 2.85% of familial FTD cases. Interestingly, no MAPT pathogenic/likely pathogenic variants were detected, suggesting possible geographical specificity. Our findings highlight the importance of wider implementation of genetic testing in neurological and psychiatric practice managing patients with cognitive-behavioral and motor symptoms. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

Background GTP cyclohydrolase 1-deficient DOPA-responsive dystonia, caused by autosomal dominant mutation in the gene coding for GTP cyclohydrolase 1, is a rare disorder with a reported prevalence of 0.5 per million. A correct diagnosis of DRD is crucial, given that this is an exquisitely treatable neurogenetic disorder. Although genetic testing is now widely available, we hypothesize that DRD is still underdiagnosed and its prevalence underestimated. Methods Molecular genetic analysis of the GCH1 gene was performed in a representative cohort of 47 Serbian patients with clinical features of DRD and in their 16 available relatives. The DRD prevalence rate in Serbia was estimated based on population size, catchment area, and the centralized Serbian referral system for rare diseases. Results We identified 9 different GCH1 mutations in 23 individuals from 11 families, 5 of which are novel. Patients displayed a broad range of clinical phenotypes. The estimated prevalence of GCH1-related DOPA-responsive dystonia in Serbia was 2.96 per million individuals and there was no evidence for a common founder. Conclusions Our data expand the genotypic spectrum of GCH1 and confirm the broad phenotypic spectrum of DRD in the Serbian population. The number of detected mutation carriers in this sample implies that the frequency of DRD in the Serbian population is considerably higher than expected based on published prevalence rates, suggesting that the prevalence of this treatable disease should be revisited also in other populations. © 2017 Elsevier Ltd

Background GTP cyclohydrolase 1-deficient DOPA-responsive dystonia, caused by autosomal dominant mutation in the gene coding for GTP cyclohydrolase 1, is a rare disorder with a reported prevalence of 0.5 per million. A correct diagnosis of DRD is crucial, given that this is an exquisitely treatable neurogenetic disorder. Although genetic testing is now widely available, we hypothesize that DRD is still underdiagnosed and its prevalence underestimated. Methods Molecular genetic analysis of the GCH1 gene was performed in a representative cohort of 47 Serbian patients with clinical features of DRD and in their 16 available relatives. The DRD prevalence rate in Serbia was estimated based on population size, catchment area, and the centralized Serbian referral system for rare diseases. Results We identified 9 different GCH1 mutations in 23 individuals from 11 families, 5 of which are novel. Patients displayed a broad range of clinical phenotypes. The estimated prevalence of GCH1-related DOPA-responsive dystonia in Serbia was 2.96 per million individuals and there was no evidence for a common founder. Conclusions Our data expand the genotypic spectrum of GCH1 and confirm the broad phenotypic spectrum of DRD in the Serbian population. The number of detected mutation carriers in this sample implies that the frequency of DRD in the Serbian population is considerably higher than expected based on published prevalence rates, suggesting that the prevalence of this treatable disease should be revisited also in other populations. © 2017 Elsevier Ltd

Background: Niemann Pick type C is an autosomal recessive lysosomal storage disorder caused by mutations in NPC1 and NPC2 genes. It is a neuro-visceral disease with a heterogeneous phenotype. Clinical features depend on the age at onset. Visceral manifestations are more prominent in the early onset (infantile) form, while neuro-psychiatric symptoms are more prominent in the late disease onset (juvenile and adult forms). Methods: A total number of 150 patients have been screened for changes in NPC1 and NPC2 gene at the Neurology Clinic, University Clinical Centre of Serbia in the period 2012–2020. Clinical data were extracted for patients with biallelic mutations. Results: Fifteen patients carried biallelic mutations in the NPC1. Out of eight different reported NPC1 variants, four are novel (c.1204_1205TT>GC, p.F402A; c.2486T>G, p.L829R; c.2795+5 G>C; c.3722T>A, p.L1241*). The mean age at the disease onset was 20.3 ± 11.9 years with the average diagnostic delay of 7.7 ± 4.3 years. Movement disorders and psychiatric or cognitive disturbances were the most common initial symptoms (in 33% and 28% patients, respectively). The average age at the first neurological manifestation was 21 ± 12.0 years. At the last examination, eye movement abnormalities (vertical slow saccades or vertical supranuclear gaze palsy), and ataxia were present in all patients, while dystonia was common (in 78.6% of patients). Presence of c.2861C>T, p.S954L mutation in homozygous state was associated with older age at the neurological symptom onset. Conclusions: Clinical findings were in line with the expected, but the diagnostic delay was common. We hypothesize that the presence of c.2861C>T, p.S954L mutation may contribute to the phenotype attenuation. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.

Background: Niemann Pick type C is an autosomal recessive lysosomal storage disorder caused by mutations in NPC1 and NPC2 genes. It is a neuro-visceral disease with a heterogeneous phenotype. Clinical features depend on the age at onset. Visceral manifestations are more prominent in the early onset (infantile) form, while neuro-psychiatric symptoms are more prominent in the late disease onset (juvenile and adult forms). Methods: A total number of 150 patients have been screened for changes in NPC1 and NPC2 gene at the Neurology Clinic, University Clinical Centre of Serbia in the period 2012–2020. Clinical data were extracted for patients with biallelic mutations. Results: Fifteen patients carried biallelic mutations in the NPC1. Out of eight different reported NPC1 variants, four are novel (c.1204_1205TT>GC, p.F402A; c.2486T>G, p.L829R; c.2795+5 G>C; c.3722T>A, p.L1241*). The mean age at the disease onset was 20.3 ± 11.9 years with the average diagnostic delay of 7.7 ± 4.3 years. Movement disorders and psychiatric or cognitive disturbances were the most common initial symptoms (in 33% and 28% patients, respectively). The average age at the first neurological manifestation was 21 ± 12.0 years. At the last examination, eye movement abnormalities (vertical slow saccades or vertical supranuclear gaze palsy), and ataxia were present in all patients, while dystonia was common (in 78.6% of patients). Presence of c.2861C>T, p.S954L mutation in homozygous state was associated with older age at the neurological symptom onset. Conclusions: Clinical findings were in line with the expected, but the diagnostic delay was common. We hypothesize that the presence of c.2861C>T, p.S954L mutation may contribute to the phenotype attenuation. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.

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Alzheimer's disease (AD) is the most common form of dementia characterized by deterioration of memory and other cognitive domains which leads to death in 3-9. years after diagnosis. In addition to mutations in APP, PSEN1 and PSEN2 genes, that cause early onset autosomal dominant AD, several genetic risk factors for late onset AD are now known.There is another distinctive neurodegenerative lysosomal storage disorder - Niemann-Pick type C (NPC) that is sometimes referred to as "Childhood Alzheimer's". NPC is autosomal recessive disease caused by mutations in the NPC1 or NPC2 genes. NPC and AD share some biochemical and pathological similarities which are discussed in this paper.On the other hand, there is a well documented connection between other autosomal recessive lysosomal storage disorder - Gaucher's disease (GD) and neurodegenerative disorder - Parkinson's disease (PD). It has been shown that GD patients have 20-fold increased life-time risk of developing PD. Surprisingly, even heterozygous carriers of mutations in glucocerebrosidase gene (GBA) have increased risk for developing PD.Having in mind above mentioned correlations, we hypothesized that heterozygous mutations in the NPC gene may act as an independent risk factor for Alzheimer's disease. If true, this would expand link between lysosomal disorders and neurodegenerative diseases. Also, if heterozygous NPC1/2 mutation carriers develop AD we assume it would be worth trying with miglustat-specific therapy recommended for NPC disease. © 2014 Elsevier Ltd.

Introduction: Classic form of pantothenate-kinase-associated neurodegeneration (PKAN), caused by mutation in PANK2 gene, is characterized by early onset, severe neurological impairment and rapid disease progression. In less precisely described form of atypical PKAN, clinical course is associated with late onset, less severe motor impairment and slower disease evolution. The aim of this study was to assess a pattern of disease progression in atypical PKAN, by following development of specific milestones. Methods: The clinical characteristics and the disease course of 9 genetically confirmed patients with atypical form of PKAN were evaluated. Time latencies from the disease onset to the appearance of specific clinical milestones were estimated in order to assess the disease progression. Results: Most frequent disease presentation in our patients was characterized with early and prominent oromandibular dystonia (OMD), followed by severe generalized dystonia and early loss of mobility within the first five years of prolonged disease duration (18.7±10.0 years). Eight out of 9 patients reached 7 significant clinical milestones (OMD, generalized dystonia, dysarthria, dysphagia, postural instability, gait difficulties, ADL dependency) in the first 4.6 years of disease course. Afterwards, a long-lasting, relatively stable period of slower progression was complicated predominantly with skeletal deformities (developed after 7.0±2.8 years). Conclusions: Majority of milestones which might significantly influence functional abilities and quality of life in patients with atypical form of PKAN developed in the course of the first five years of the disease, followed by a long-lasting, relatively stable period of slower progression. © 2015 Elsevier Ltd.

Introduction: Classic form of pantothenate-kinase-associated neurodegeneration (PKAN), caused by mutation in PANK2 gene, is characterized by early onset, severe neurological impairment and rapid disease progression. In less precisely described form of atypical PKAN, clinical course is associated with late onset, less severe motor impairment and slower disease evolution. The aim of this study was to assess a pattern of disease progression in atypical PKAN, by following development of specific milestones. Methods: The clinical characteristics and the disease course of 9 genetically confirmed patients with atypical form of PKAN were evaluated. Time latencies from the disease onset to the appearance of specific clinical milestones were estimated in order to assess the disease progression. Results: Most frequent disease presentation in our patients was characterized with early and prominent oromandibular dystonia (OMD), followed by severe generalized dystonia and early loss of mobility within the first five years of prolonged disease duration (18.7±10.0 years). Eight out of 9 patients reached 7 significant clinical milestones (OMD, generalized dystonia, dysarthria, dysphagia, postural instability, gait difficulties, ADL dependency) in the first 4.6 years of disease course. Afterwards, a long-lasting, relatively stable period of slower progression was complicated predominantly with skeletal deformities (developed after 7.0±2.8 years). Conclusions: Majority of milestones which might significantly influence functional abilities and quality of life in patients with atypical form of PKAN developed in the course of the first five years of the disease, followed by a long-lasting, relatively stable period of slower progression. © 2015 Elsevier Ltd.

Background: In addition to the most frequent TOR1A/DYT1 mutation (c.907_909delGAG), a growing number of TOR1A sequence variants are found in dystonia patients. For most, functional characterization has demonstrated pathogenicity at different levels, implying that TOR1A genetic testing should not be limited to screening for c.907_909delGAG. Methods: We tested 461 Serbian patients with isolated or combined dystonia for changes in the TOR1A gene and performed a systematic literature review of the clinical characteristics of patients carrying TOR1A mutations other than c.907_909delGAG. Results: One likely pathogenic TOR1A mutation (c.385G>A, p.Val129Ile) was detected in an adult-onset cervical dystonia patient. This change is in proximity to the previously reported p.Glu121Lys mutation and predicted to decrease the stability of TOR1A-encoded protein TorsinA. Conclusions: Our patient and three other reported carriers of non-c.907_909delGAG-mutations within the first three exons of TOR1A showed similar phenotypes of adult-onset focal or segmental cervical dystonia. This observation raises the possibility of genotype-phenotype correlations in DYT1 and indicates that the clinical spectrum of this type of dystonia might be broader then previous classic descriptions. © 2015 Elsevier Ltd.

Background: In addition to the most frequent TOR1A/DYT1 mutation (c.907_909delGAG), a growing number of TOR1A sequence variants are found in dystonia patients. For most, functional characterization has demonstrated pathogenicity at different levels, implying that TOR1A genetic testing should not be limited to screening for c.907_909delGAG. Methods: We tested 461 Serbian patients with isolated or combined dystonia for changes in the TOR1A gene and performed a systematic literature review of the clinical characteristics of patients carrying TOR1A mutations other than c.907_909delGAG. Results: One likely pathogenic TOR1A mutation (c.385G>A, p.Val129Ile) was detected in an adult-onset cervical dystonia patient. This change is in proximity to the previously reported p.Glu121Lys mutation and predicted to decrease the stability of TOR1A-encoded protein TorsinA. Conclusions: Our patient and three other reported carriers of non-c.907_909delGAG-mutations within the first three exons of TOR1A showed similar phenotypes of adult-onset focal or segmental cervical dystonia. This observation raises the possibility of genotype-phenotype correlations in DYT1 and indicates that the clinical spectrum of this type of dystonia might be broader then previous classic descriptions. © 2015 Elsevier Ltd.