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.

We investigated a group of 30 male patients with a clinically heterogenous phenotype ranging from non-specific mental retardation to a severe neonatal encephalopathy. We found the c.1282 G>A (G428S) nucleotide change in a boy with a severe encephalopathy, the c.1030 C>T (R344W) variation in a male with a Rett-like phenotype, and the c.590 C>T (T197M) variation in a male with congenital encephalopathy, microcephaly, and severe developmental delay. Furthermore, by screening our female Rett patients, we found the c.1196 C>T (P399L) in a patient of German origin and the c.1126 C>T (P376S) variation in a girl of Korean origin, both nucleotide changes having been detected in their corresponding healthy father. Except for the c.590 C>T (T197M) variation, located between the MBD and TRD domains of MECP2, all amino acid changes affect the C-terminal segment of the MeCP2 protein downstream from the MBD and TRD.

Background—: Studies of recurrent or subsequent disease events may be susceptible to bias caused by selection of subjects who both experience and survive the primary indexing event. Currently, the magnitude of any selection bias, particularly for subsequent time-to-event analysis in genetic association studies, is unknown. Methods and Results—: We used empirically inspired simulation studies to explore the impact of selection bias on the marginal hazard ratio for risk of subsequent events among those with established coronary heart disease. The extent of selection bias was determined by the magnitudes of genetic and nongenetic effects on the indexing (first) coronary heart disease event. Unless the genetic hazard ratio was unrealistically large (>1.6 per allele) and assuming the sum of all nongenetic hazard ratios was <10, bias was usually <10% (downward toward the null). Despite the low bias, the probability that a confidence interval included the true effect decreased (undercoverage) with increasing sample size because of increasing precision. Importantly, false-positive rates were not affected by selection bias. Conclusions—: In most empirical settings, selection bias is expected to have a limited impact on genetic effect estimates of subsequent event risk. Nevertheless, because of undercoverage increasing with sample size, most confidence intervals will be over precise (not wide enough). When there is no effect modification by history of coronary heart disease, the false-positive rates of association tests will be close to nominal.

The Investigator DIPplex^® kit (Qiagen) contain components for the simultaneous amplification and analysis of 30 biallelic autosomal INDELs and amelogenin. The objective of this study was to estimate the diversity of the 30 markers in Polish (N _P = 122) and Taiwanese (N _T = 126) population samples and to evaluate their usefulness in forensic genetics. All amplicon lengths were shorter than 160 base pairs. The DIPplex genotype distributions showed no significant deviation from Hardy–Weinberg rule expectations (Bonferroni corrected) except for DLH39 in the Taiwanese population. Among the Poles and the Taiwanese the mean observed heterozygosity values are 0.4385 and 0.4079, and the combined matching probability values are 7.98 × 10⁻¹⁴ and 1.22 × 10⁻¹¹, respectively. The investigated marker set has been confirmed as a potential extension to standard short tandem repeat-based kits or a separate informative system for individual identification and kinship analysis. Eight INDELs have been selected as possible ancestry informative single-nucleotide polymorphisms for further analyses.