In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.

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Relevant for various areas of human genetics, Y-chromosomal short tandem repeats (Y-STRs) are commonly used for testing close paternal relationships among individuals and populations, and for male lineage identification. However, even the widely used 17-loci Yfiler set cannot resolve individuals and populations completely. Here, 52 centers generated quality-controlled data of 13 rapidly mutating (RM) Y-STRs in 14,644 related and unrelated males from 111 worldwide populations. Strikingly, >99% of the 12,272 unrelated males were completely individualized. Haplotype diversity was extremely high (global: 0.9999985, regional: 0.99836–0.9999988). Haplotype sharing between populations was almost absent except for six (0.05%) of the 12,156 haplotypes. Haplotype sharing within populations was generally rare (0.8% nonunique haplotypes), significantly lower in urban (0.9%) than rural (2.1%) and highest in endogamous groups (14.3%). Analysis of molecular variance revealed 99.98% of variation within populations, 0.018% among populations within groups, and 0.002% among groups. Of the 2,372 newly and 156 previously typed male relative pairs, 29% were differentiated including 27% of the 2,378 father–son pairs. Relative to Yfiler, haplotype diversity was increased in 86% of the populations tested and overall male relative differentiation was raised by 23.5%. Our study demonstrates the value of RM Y-STRs in identifying and separating unrelated and related males and provides a reference database.

Sudden infant death syndrome (SIDS) is described as the sudden and unexplained death of an apparently healthy infant younger than one year of age. Genetic studies indicate that up to 35% of SIDS cases might be explained by familial or genetic diseases such as cardiomyopathies, ion channelopathies or metabolic disorders that remained undetected during conventional forensic autopsy procedures. Post-mortem genetic testing by using massive parallel sequencing (MPS) approaches represents an efficient and rapid tool to further investigate unexplained death cases and might help to elucidate pathogenic genetic variants and mechanisms in cases without a conclusive cause of death. In this study, we performed whole-exome sequencing (WES) in 161 European SIDS infants with focus on 192 genes associated with cardiovascular and metabolic diseases. Potentially causative variants were detected in 20% of the SIDS cases. The majority of infants had variants with likely functional effects in genes associated with channelopathies (9%), followed by cardiomyopathies (7%) and metabolic diseases (1%). Although lethal arrhythmia represents the most plausible and likely cause of death, the majority of SIDS cases still remains elusive and might be explained by a multifactorial etiology, triggered by a combination of different genetic and environmental risk factors. As WES is not substantially more expensive than a targeted sequencing approach, it represents an unbiased screening of the exome, which could help to investigate different pathogenic mechanisms within the genetically heterogeneous SIDS cohort. Additionally, re-analysis of the datasets provides the basis to identify new candidate genes in sudden infant death.

Messenger RNA (mRNA) expression varies among cell types; therefore, analyses for the presence of particular mRNAs can be used to identify biological fluids in forensic samples. For this work, several novel markers were characterized for saliva, cervicovaginal fluid (CVF), blood, and menstrual blood (MB). The new markers were used in combination with previously described markers to develop four multiplex polymerase chain reaction assays. These multiplexes incorporate two housekeeping and a minimum of five markers for each of the following forensically relevant body fluids: semen, saliva, CVF, blood, and MB. A large number of samples (>200) were analyzed to determine specificity of each marker. The majority of the markers were detected at low frequencies in non-target body fluids. Because markers were not specific to their respective target body fluids, a scoring system was developed to minimize the chances of misidentification of a sample due to marker expression in a non-target body fluid. Each marker was given a numerical value related to its "correct" (target body fluid) versus "incorrect" (non-target body fluid) expression in samples of known origin. For each of the five body fluids, the marker values of those mRNA markers that were present in a sample were added to produce a body fluid score. Threshold scores were then determined for the identification of each body fluid. Although this study highlights the complexity of body fluid identification, particularly in differentiating blood and MB, the use of threshold scores allowed for reliable body fluid identification in the samples tested.