Evaluation of the genetic parameters for 10 common and five new ESS core autosomal STR loci in seven major geographic regions and the largest metropolitan province of Turkey.

BACKGROUND: Situated at the crossroads of Asia, Middle East and Europe, Turkey has an ethnically diverse population of over 78 milllion people. AIM: To investigate the population genetics and potential differences in the autosomal short tandem repeat (STR) polymorphisms across all the major geographic regions and largest metropolitan province of Turkey within the context of the Near Eastern/European genetic landscape. SUBJECTS AND METHODS: Samples from a total of 5299 unrelated individuals were analysed at 10 common [D2S1338, D3S1358, D8S1179, D16S539, D18S51, D19S433, D21S11, FGA, TH01, vWA] and five new European Standard Set (ESS) core autosomal STR loci [D1S1656, D2S441, D10S1248, D12S391, D22S1045]. RESULTS: Allele frequencies, statistical parameters of forensic interest and population differentiation tests were calculated for nine population datasets corresponding to the seven major geographic regions, the largest metropolitan province, and a combined dataset for the entire country. Cumulative results confirmed the presence of significant differences among these nine autosomal datasets themselves and with those from the nearby populations, therefore justifying the differential use of these separate datasets on a case-by-case basis in forensic investigations. CONCLUSION: This collection of autosomal STR population datasets comprises the largest and most comprehensive of its kind from Turkey so far.

Two brothers' alleged paternity for a child: who is the father?

In paternity cases where individuals are close relatives, it may be necessary to evaluate mother's DNA profile (trio test) and to increase the number of polymorphic STR loci that are analyzed. In our case, two alleged fathers who are brothers and the child (duo case) were analyzed based on 20 STR loci; however, no exclusions could be achieved. Then trio test (with mother) was performed using the Identifiler Plus kit (Applied Biosystems) and no exclusions could be achieved again. Analysis performed with the ESS Plex Plus kit (Qiagen), the paternity of one of the two alleged fathers was rejected only on 2 STR loci. We made the calculations of power of exclusion values to interpret our results more properly. The probability of exclusion (PE) is calculated as 0.9776546 in 15 loci of Identifiler Plus kit without mother. The PE is calculated as 0.9942803, if 5 additional loci from ESS Plex Plus kit are typed. The PE becomes 0.9961048 for the Identifiler Plus kit in trio analysis. If both Identifiler Plus and ESS Plex Plus kits are used for testing, the PE is calculated as 0.999431654, which indicates that the combined kits are highly discriminating.

Investigation of key miRNAs and target genes in bladder cancer using miRNA profiling and bioinformatic tools.

Despite the association of several miRNAs with bladder cancer, little is known about the miRNAs' regulatory networks. In this study, we aimed to construct potential networks of bladder-cancer-related miRNAs and their known target genes using miRNA expression profiling and bioinformatics tools and to investigate potential key molecules that might play roles in bladder cancer regulatory networks. Global miRNA expression profiles were obtained using microarray followed by RT-qPCR validation using two randomly selected miRNAs. Known targets of deregulated miRNAs were utilized using DIANA-TarBase database v6.0. The incorporation of deregulated miRNAs and target genes into KEGG pathways were utilized using DIANA-mirPath software. To construct potential miRNA regulatory networks, the overlapping parts of three selected KEGG pathways were visualized by Cytoscape software. We finally gained 19 deregulated miRNAs, including 5 ups- and 14 down regulated in 27 bladder-cancer tissue samples and 8 normal urothelial tissue samples. The enrichment results of deregulated miRNAs and known target genes showed that most pathways were related to cancer or cell signaling pathways. We determined the hub CDK6, BCL2, E2F3, PTEN, MYC, RB, and ERBB3 target genes and hub hsa-let-7c, hsa-miR-195-5p, hsa-miR-141-3p, hsa-miR-26a-5p, hsa-miR-23b-3p, and hsa-miR-125b-5p miRNAs of the constructed networks. These findings provide new insights into the bladder cancer regulatory networks and give us a hypothesis that hsa-let-7c, hsa-miR-195-5p, and hsa-miR-125b-5p, along with CDK4 and CDK6 genes might exist in the same bladder cancer pathway. Particularly, hub miRNAs and genes might be potential biomarkers for bladder cancer clinics.

An incest case with three biological brothers as alleged fathers: Even 22 autosomal STR loci analysis would not suffice without the mother.

Here, we report an incest paternity case involving three biological brothers as alleged fathers (AFs), their biological sister and her child that was investigated using the Investigator ESSplex Plus, AmpFLSTR Identifiler Plus/Investigator IDplex Plus and PowerPlex 16 kits. Initial duo paternity investigations using 15-loci autosomal short tandem repeat (STR) analyses failed to exclude any of the AFs. Despite the fact that one of the brothers, AF1, had a mismatch with the child at a single locus (D2S1338), the possibility of a single-step mutation could not be ruled out. When the number of autosomal STR loci analysed was increased to 22 without the inclusion of the mother, AF2 and AF3 still could not be excluded, since both of them again had no mismatches with the child. A breakthrough was possible only upon inclusion of the mother so that trio paternity investigations were carried out. This time AF1 and AF2 could be excluded at two loci (D2S1338 and D1S1656) and six loci (vWa, D1S1656, D12S391, FGA, PENTA E and PENTA D), respectively, and AF3 was then the only brother who could not be excluded from paternity. Subsequent statistical analyses suggested that AF3 could be the biological father of the child with a combined paternity index >100 billion and a probability of paternity >99.99999999%. These findings consolidate the fact that complex paternity cases such as those involving incest could benefit more from the inclusion of the mother than simply increasing the number of STR loci analysed.

Evaluation of incest cases of Turkey in terms of DNA profiling difficulties.

We scanned suspicious 1200 paternity cases and 650 sexual abuse victims in Council of Forensic Medicine of Turkey between 2011 and 2014 and detected 50 incest cases and evaluated the forensic and genetic data of incest cases for source of DNA evidence, gender, age, SES (Socioeconomic status) and geographic location of victim, abusive person, extent of incest, pregnancy from incest and date of gestation termination and also aimed to discuss some DNA profiling difficulties. We detected incest from DNA evidences of curettage material (34%; Chorionic Villi (12%) and fetal tissue (22%)), alive baby after pregnancy (28%), sperm in vaginal swab (10%), sperm in anal swab (2%), sperm on clothing (24%) and in one case both sperm on clothing and in vaginal swab (2%). It was found that the most common incestuous relationship was elder-brother-sister incest (34%) and the second most common relationship was father-daughter incest (28%). The rarest incest was mother-son incest with only one reported case (2%). Forty-three victims (86%) were younger than 18 years old and 7 victims (14%) were older than 18 years old. Thirty-eight cases described full sexual intercourse and 31 of them culminated in pregnancy and 14 of them gave birth at the end of pregnancy. We had paternity rejection problem 3 (10%) of 31 incest cases between tested genetically related alleged fathers. Totally 20 STR loci did not discriminate the alleged fathers in two cases and we treated this problem increasing the number of STR loci and finally got the discrimination. In one case we detected same triallelic variant pattern at the same D3S1358 STR locus in both tested parents but child had not got STR variant; had only two alleles at this loci. We then evaluated the peak height values of STR variant alleles of tested persons and concluded a tetra-allelic baby without any STR incompatibility of 15 STR loci. Finally, forensic experts should aware of some DNA profiling difficulties while analyzing paternity incest cases due to increasing intra familial allelic share. We suggested that first try increasing the number of compared STR loci and secondly use alternative genetic markers and also be careful while evaluating triallelic STR variants.

Current status of the use of single-nucleotide polymorphisms in forensic practices.

Forensic geneticists often use short tandem repeats (STRs) to solve cases. However, STRs can be insufficient when DNA samples are degraded due to environmental exposure and mass disasters, alleged and real relatives are genetically related in paternity or kinship analyses, or a suspect is lacking. In such cases, single-nucleotide polymorphisms (SNPs) can provide valuable information and thus should be seriously considered as a tool to help resolve challenging cases. In this review, the current status of SNP analyses in forensic applications and the comparative advantages and disadvantages of SNPs with other biomarkers are discussed.