A comprehensive mutation study in wide deep-rooted R1b Serbian pedigree: mutation rates and male relative differentiation capacity of 36 Y-STR markers.

Haplotyping of Y-chromosomal short tandem repeats (Y-STRs) reflects the paternal lineage, although, the father-son pair profiles may differ due to the germline mutations. In order to discriminate between closely related males in criminal cases, as well as for the correct application of Y-STRs in the paternity/kinship analysis and determination of the most recent common ancestor in the familial searching or genealogy research, the assessment of mutation rates of routinely used Y-STRs is of a great importance. We genotyped 120 males belonging to one wide deep-rooted pedigree separated by 1-20 meiosis. The haplotypes of analyzed males distributed over 12 different families (according to their surnames), with 113 originating from one ancestor, and the remaining 7 from the second, closely related to the previous one, belong to the R1b haplogroup. The analysis was performed using Powerplex® Y23 kit, Yfiler™ plus kit and 13 rapidly mutating (RM13) Y-STRs. In 20,855 allele transmissions, 175 mutations (61% repeat losses and 39% gains) and one gene conversion event were found at 25 out of 36 markers. The medians of locus-specific mutation rates estimated using the Bayesian approach ranged from 1.42 × 10-3 (95% credible interval (CI): 0.05 × 10-3 - 7.56 × 10-3) for loci with no observed mutations to 130.91 × 10-3 (95% CI: 102.91 × 10-3 - 162.78 × 10-3) for DYF399S1, with a median rate across all 36 markers of 10.06 × 10-3 (95% CI: 8.65 × 10-3 - 11.61 × 10-3). In 6349 male relative pairs, the 36 Y-STR set distinguished 98.4% relative pairs by at least one mutation, compared to 95.9%, 65.5% and 57.4% for RM13, Yfiler™ plus, and Powerplex® Y23 set, respectively. The extra-pair paternity rate was estimated at 11.9 × 10-3 (95% CI: 4.4 × 10-3 - 25.8 × 10-3) fitting within the range reported for some European populations. A significant positive correlation was observed between fathers' ages at the time of the Y chromosome transmission and mutability rates (R2 = 0.9495, p = 0.0256), with more significant results when analyzing RM markers (R2 = 0.9827, p = 0.0087).

Comparison of different methods of DNA recovery and PCR amplification in STR profiling of casings-a retrospective study.

Casings represent common evidence in a forensic laboratory, due to high frequency of firearms usage during perpetration of criminal offenses. Possible DNA evidence from casings is compromised by degradation, inhibition, and initial low-quantity deposition of biological material. For that reason, in the last 15 years, scientists have been trying to optimize procedures for recovery and amplification of DNA possibly present on its surface. In this study, we share our 12-year experience done on a total of 698 casework casings, comparing two DNA recovery methods commonly used-soaking and swabbing, as well as efficacy of two commercially available DNA amplification kits (AmpFLSTR® Identifiler® and AmpFLSTR® Identifiler® Plus kits). Of all analyzed casings, 30 were excluded as 28 (4%) matched the victims' DNA profiles and 2 (0.3%) samples were proved to be contaminated by technicians. Overall success in obtaining interpretable DNA profiles was 15.6% (104/668) (13.8% (55/399) for AmpFLSTR® Identifiler® Plus combined with soaking, 22% (33/150) for AmpFLSTR® Identifiler® Plus combined with swabbing, and 13.4% (16/119) using AmpFLSTR® Identifiler® kit and swabbing recovery method). Our data suggest the importance of both DNA recovery methods and amplification kits used, and point out swabbing of casings combined with AmpFLSTR® Identifiler® Plus kit as methods of choice. Nonetheless, our results are based on real casework and are prone to uncontrolled variables.

Differentiation of Cannabis subspecies by THCA synthase gene analysis using RFLP.

Cannabis sativa subspecies, known as industrial hemp (C. sativa sativa) and marijuana (C. sativa indica) show no evident morphological distinctions, but they contain different levels of psychoactive Δ-9-tetrahidrocanabinol (THC), with considerably higher concentration in marijuana than in hemp. C. sativa subspecies differ in sequence of tetrahydrocannabinolic acid (THCA) synthase gene, responsible for THC production, and only one active copy of the gene, distinctive for marijuana, is capable of producing THC in concentration more then 0,3% in dried plants, usually punishable by the law. Twenty different samples of marijuana that contain THC in concentration more then 0,3% and three varieties of industrial hemp were analyzed for presence of an active copy of THCA synthase gene using in-house developed restriction fragment length polymorphism (RFLP) method All twenty samples of marijuana were positive for the active copy of THCA synthase gene, 16 of them heterozygous. All three varieties of industrial hemp were homozygous for inactive copy. An algorithm for the fast and accurate forensic analysis of samples suspected to be marijuana was constructed, answering the question if an analyzed sample is capable of producing THC in concentrations higher than 0.3%.

Genetics of Lafora progressive myoclonic epilepsy: current perspectives.

Lafora disease (LD) is a fatal neurodegenerative disorder caused by loss-of-function mutations in either laforin glycogen phosphatase gene (EPM2A) or malin E3 ubiquitin ligase gene (NHLRC1). LD is associated with gradual accumulation of Lafora bodies (LBs). LBs are aggregates of polyglucosan, a long, linear, poorly branched, hyperphosphorylated, insoluble form of glycogen. Loss-of-function mutations either in the EPM2A or in the NHLRC1 gene lead to polyglucosan formation. One hypothesis on LB formation is based on findings that laforin-malin complex downregulates glycogen synthase (GS) through malin-mediated ubiquitination, and the other one is based on findings that laforin dephosphorylates glycogen. According to the first hypothesis, polyglucosan formation is a result of increased GS activity, and according to the second, an increased glycogen phosphate leads to glycogen conformational change, unfolding, precipitation, and conversion to polyglucosan, while GS remains bound to the precipitating glycogen. In this review, we summarize all the recent findings that have important implications for the treatment of LD, all of them showing that partial inhibition of GS activity may be sufficient to prevent the progression of the disease. The current perspective in LD is high-throughput screening for small molecules that act on the disease pathway, that is, partial inhibitors of GS, which opens a therapeutic window for potential treatment of this fatal disease.

A shared haplotype indicates a founder event in Unverricht-Lundborg disease patients from Serbia.

Unverricht-Lundborg disease (ULD) is an autosomal recessive disorder caused by dodecamer repeat expansion in the promoter region of the cystatin B (CSTB) gene in approximately 90% of the disease alleles worldwide. This study presents results of genetic findings in four Serbian unrelated patients with clinical and molecular diagnosis of ULD. Using newly established PCR protocol with betaine, we detected a homozygous expansion of dodecamer repeats in the CSTB gene in four patients with clinical diagnosis of ULD. Our results are in agreement with previous studies showing that dodecamer repeats expansion is the most common mutation associated with ULD. Haplotype analysis of eight unrelated ULD chromosomes was performed using seven markers flanking CSTB gene and one intragenic variant. We demonstrated the existence of a founder effect, strongly supported by LD calculations. Size of the minimal common haplotype implies that the most recent common ancestor of the Serbian ULD patients lived about 110 generations ago. We showed that Serbian ULD patients share the same common ancestor with patients from Baltic countries and North Africa. In the light of our data, we proposed extended minimal common haplotype, which could be considered as initial haplotype of the founder event common for Serbian, Baltic, and North African ULD patients.

Lafora disease: severe phenotype associated with homozygous deletion of the NHLRC1 gene.

Lafora disease (LD) is a severe, autosomal recessive, latechildhood- to teenage-onset, progressive myoclonic epilepsy. It is due to either EPM2A or NHLRC1 mutations. We describe a patient with homozygous deletion encompassing the entire NHLRC1 gene, not previously reported, and with clinical course more progressive than in the most patients with NHLRC1 mutations. The diagnosis of LD in our patient was based on the typical clinic, neurophysiological presentation, as well as skin biopsy followed by molecular genetics findings. She developed normally until the age of 15, when she had her first occipital and generalized seizures. Four years after the first seizure the patient became bedridden, demented and presented with severe clinical condition. She died of pneumonia at age 20. This report is the first case of homozygosity for NHLRC1 deletion and thus adds to mutational heterogeneity of LD. Besides, it widens the spectrum of LD patients with severe phenotype and NHLRC1 mutations.

An algorithm for genetic testing of Serbian patients with demyelinating Charcot-Marie-Tooth.

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.

A novel P66S mutation in exon 3 of the SOD1 gene with early onset and rapid progression.

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease in adults of unknown origin in most cases. Here we report a novel P66S mutation in exon 3 of the SOD1 gene in an apparently sporadic ALS patient with unusual early onset and rapid disease progression. Our data widen the spectrum of SOD1 mutations and clinical presentations of ALS.

Polymorphisms of the prion protein gene (PRNP) in a Serbian population.

Prion diseases are a group of etiologically heterogeneous neurodegenerative disorders. We have analyzed the coding region of PRNP gene in 121 healthy citizens of Serbia to determine whether the frequencies of M129V, E219K, and octapeptide repeat number polymorphism. For Serbian population, polymorphism of PRNP gene at codon 129 does not differ from healthy European populations. Also codon 219 is monomorphic for the Glu allele both in Serbian population and other European populations. On the contrary, in Serbian population we did not detect any deletions or insertions in octapeptide repeat region, whereas deletions were detected in other European populations.

Schizophrenia and apolipoprotein E gene polymorphism in Serbian population.

Apolipoprotein E (APOE) gene variants are associated with alterations in brain function and increased risk of Alzheimer's disease (AD) and conflicting results have been reported in schizophrenia. Our results showed no significant differences in APOE allele or genotype frequencies between the Serbian schizophrenic patients and control individuals. However, we observed a possible association between particular subtypes of schizophrenia and APOE epsilon3/epsilon3 genotype (p = .01221) and epsilon4 allele showed a tendency toward positive association with responding to typical neuroleptics. APOE genotypes have no major influence on risk of schizophrenia, treatment and response to conventional antipsychotics, and age of onset in schizophrenia.

Mutational analysis of GJB1, MPZ, PMP22, EGR2, and LITAF/SIMPLE in Serbian Charcot-Marie-Tooth patients.

We report the results of mutational analysis in the following genes: GJB1, MPZ, PMP22, EGR2, and LITAF/SIMPLE in 57 Charcot-Marie-Tooth (CMT) patients of Serbian origin without the PMP22 duplication. We found 10 different mutations in 14 CMT patients: 6 mutations in GJB1, 3 in MPZ, and 1 in PMP22. Five of six GJB1 mutations are reported for the first time, and the most frequent one appears to be a founder mutation in the Serbian population. No mutations were found in EGR2 or LITAF. Thus, GJB1 mutation analysis should be done in patients without the PMP22 duplication and male-to-male transmission of CMT.

Coexistence of Unverricht-Lundborg disease and congenital deafness: molecular resolution of a complex comorbidity.

PURPOSE: We report on genetic analysis of a complex condition in a Serbian family of four siblings, wherein two had progressive myoclonic epilepsy (PME) and congenital deafness (CD), one had isolated congenital deafness (ICD), and one was healthy. METHODS AND RESULTS: Molecular diagnosis performed by Southern blotting confirmed Unverricht-Lundborg disease in the available sibling with PME/CD. In the sibling with ICD (heterozygote for expansion mutation in CSTB) we demonstrated recombination event between the D21S2040 marker and the CSTB gene and identified c.207delC (p.T70Xfs) mutation in the fourth exon of the transmembrane protease, serine-3 (TMPRSS3) gene (maps in close proximity to CSTB), responsible for nonsyndromic deafness in the sibling with PME/CD as well. DISCUSSION: To the best of our knowledge this is the first genetic confirmation of the coexistence of these two mutations.

Human Y-specific STR haplotypes in population of Serbia and Montenegro.

Nine Y chromosome short tandem repeat (STR) loci (DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393) were analyzed in group of 237 unrelated healthy males from population of Serbia and Montenegro in order to assess the frequencies of Y haplotypes. We observed 174 different haplotypes of which 146 (61.6%) were seen only once. Y-STR allelic frequencies in Serbia and Montenegro, in general, correspond to other European populations, except for the DYS19, DYS385 and DYS389II loci.