Maturity-onset diabetes of the young: an update.

Maturity-onset diabetes of the young (MODY) is a dominantly inherited form of non-ketotic diabetes. It usually develops in childhood, adolescence or young adulthood. The disease is heterogenous regarding the genetic and clinical features. Until now, 6 causal genes have been identified. According to clinical evidence there is at least one further MODY gene. MODY2 is caused by mutations in the glucokinase gene, which encodes the signal protein for insulin secretion. The remaining MODY subtypes are the result of mutations in genes coding for transcription factors. MODY2 and MODY3 are by far the most frequent forms. Patients with MODY2 have mild, asymptomatic and stable hyperglycemia that is present from birth. They rarely develop microvascular disease, and seldom require pharmacologic treatment. MODY3 patients usually develop severe hyperglycemia after puberty, which often leads to the diagnosis of diabetes type 1. Despite the progression of hyperglycemia, sensitivity to sulfonylureas is retained in MODY3 patients for many years. Diabetic retinopathy and nephropathy frequently occur in MODY3 patients. Other risk factors are not present. The frequency of cardiovascular disease is not increased. Due to the pleiotropic character of the transcription factors most MODY subtypes are diseases with multi-organ involvement in addition to diabetes. MODY5 appears to be much more frequent than originally assumed. This form is associated with pancreatic atrophy, renal morphologic and functional abnormalities, genital tract malformations and pathological liver test. Compared to MODY2, 3, and 5, the remaining subtypes of MODY have a much lower prevalence. Molecular diagnosis has important consequences for prognosis, family screening and therapy.

Methylation Markers for the Identification of Body Fluids and Tissues from Forensic Trace Evidence.

The identification of body fluids is an essential tool for clarifying the course of events at a criminal site. The analytical problem is the fact that the biological material has been very often exposed to detrimental exogenous influences. Thereby, the molecular substrates used for the identification of the traces may become degraded. So far, most protocols utilize cell specific proteins or RNAs. Instead of measuring these more sensitive compounds this paper describes the application of the differential DNA-methylation. As a result of two genome wide screenings with the Illumina HumanMethylation BeadChips 27 and 450k we identified 150 candidate loci revealing differential methylation with regard to the body fluids venous blood, menstrual blood, vaginal fluid, saliva and sperm. Among them we selected 9 loci as the most promising markers. For the final determination of the methylation degree we applied the SNuPE-method. Because the degree of methylation might be modified by various endogenous and exogenous factors, we tested each marker with approximately 100 samples of each target fluid in a validation study. The stability of the detection procedure is proved in various simulated forensic surroundings according to standardized conditions. We studied the potential influence of 12 relatively common tumors on the methylation of the 9 markers. For this purpose the target fluids of 34 patients have been analysed. Only the cervix carcinoma might have an remarkable effect because impairing the signal of both vaginal markers. Using the Illumina MiSeq device we tested the potential influence of cis acting sequence variants on the methylation degree of the 9 markers in the specific body fluid DNA of 50 individuals. For 4 marker loci we observed such an influence either by sole SNPs or haplotypes. The identification of each target fluid is possible in arbitrary mixtures with the remaining four body fluids. The sensitivity of the individual body fluid tests is in the same range as for the forensic STR-analysis. It is the first forensic body fluid protocol which considers the exogenic and endogenic parameters potentially interfering with the true results.

Correction: Methylation Markers for the Identification of Body Fluids and Tissues from Forensic Trace Evidence.

[This corrects the article DOI: 10.1371/journal.pone.0147973.].

The cellular ratio of immune tolerance (immunoCRIT) is a definite marker for aggressiveness of solid tumors and may explain tumor dissemination patterns.

The adaptive immune system is involved in tumor establishment and aggressiveness. Tumors of the ovaries, an immune-privileged organ, spread via transceolomic routes and rarely to distant organs. This is contrary to tumors of non-immune privileged organs, which often disseminate hematogenously to distant organs. Epigenetics-based immune cell quantification allows direct comparison of the immune status in benign and malignant tissues and in blood. Here, we introduce the "cellular ratio of immune tolerance" (immunoCRIT) as defined by the ratio of regulatory T cells to total T lymphocytes. The immunoCRIT was analyzed on 273 benign tissue samples of colorectal, bronchial, renal and ovarian origin as well as in 808 samples from primary colorectal, bronchial, mammary and ovarian cancers. ImmunoCRIT is strongly increased in all cancerous tissues and gradually augmented strictly dependent on tumor aggressiveness. In peripheral blood of ovarian cancer patients, immunoCRIT incrementally increases from primary diagnosis to disease recurrence, at which distant metastases frequently occur. We postulate that non-pathological immunoCRIT values observed in peripheral blood of immune privileged ovarian tumor patients are sufficient to prevent hematogenous spread at primary diagnosis. Contrarily, non-immune privileged tumors establish high immunoCRIT in an immunological environment equivalent to the bloodstream and thus spread hematogenously to distant organs. In summary, our data suggest that the immunoCRIT is a powerful marker for tumor aggressiveness and disease dissemination.

MtDNA typing of single-sperm cells isolated by micromanipulation.

Some sexual assault crimes constitute a problem for the legal institutions confronted with the DNA analysis of such cases. Often, sperm cells are found in the victim's vaginal tract during medical examination but their successful genotyping is compromised by the huge excess of the victim's epithelial cells as well as by the degradation of genomic DNA present in sperm cells as a consequence of female immune response. Mitochondrial DNA present in the mid-piece of sperm cells might be useful in some specific cases in order to differentiate the donors of a semen sample. The high number of copies per cell and its circular nature that may confer some protection from the action of exonucleases make it more suitable for cases where few cells are available and/or the DNA is degraded. We have developed a novel strategy for typing mtDNA from single-sperm cells. Specific amplification of male mitochondrial DNA is ensured by use of sequence specific primers designed on the basis of mitochondrial single nucleotide polymorphisms existent throughout the control region. The strategy was applied to single-sperm cells isolated by micromanipulation from slides smeared with vaginal swabs taken immediately after sexual intercourse of voluntary couples. After sequencing the PCR products, it was possible to obtain a match between the DNA sequence from the buccal swab and the DNA sequence of the single sperm-cell, for each voluntary man. With this new strategy, the problem of contamination with DNA from the victim observed when using universal primers was completely overtaken. This method will probably allow the resolution of multiple-rapist crimes, where the collected sperm cells can be separately typed.

Examination of postmortem animal interference to human remains using cross-species multiplex PCR.

Postmortem animal interference may be confused at first sight with injuries of vital origin, thus arousing suspicion of external violence preceding death. A reliable classification of the origin of such doubtful injuries is of crucial importance, a fact that is especially true for the investigation of suspected homicide and/or mammade body mutilation after death. In forensic pathology, the identification of injuries as caused by animals postmortem and the classification of a particular species as responsible for a specific injury pattern under question is usually done by forensic pathologists with vast practical experience and special knowledge of the appearance and morphology of tooth marks of carnivores and rodents, respectively. However, a molecular biological investigation of such wounds could provide genetic evidence that an injury pattern present on a corpse was truly caused postmortem by animal interference and thus support the pathologist's expertise. For this purpose, we developed a panel of small species-specific short-tandem repeat systems (<150 bp) for animals typically involved in postmortem scavenging of human remains, such as dogs and cats as well as wild-living rodents (mice and rats) having possible access to death scenes inside apartments or buildings. A specific and sensitive cross-species multiplex polymerase chain reaction was then established including the species-specific animal markers, thus enabling the genetic identification of wounds caused postmortem by different animals on human remains.

Mitochondrial DNA and the origins of the domestic horse.

The place and date of the domestication of the horse has long been a matter for debate among archaeologists. To determine whether horses were domesticated from one or several ancestral horse populations, we sequenced the mitochondrial D-loop for 318 horses from 25 oriental and European breeds, including American mustangs. Adding these sequences to previously published data, the total comes to 652, the largest currently available database. From these sequences, a phylogenetic network was constructed that showed that most of the 93 different mitochondrial (mt)DNA types grouped into 17 distinct phylogenetic clusters. Several of the clusters correspond to breeds and/or geographic areas, notably cluster A2, which is specific to Przewalski's horses, cluster C1, which is distinctive for northern European ponies, and cluster D1, which is well represented in Iberian and northwest African breeds. A consideration of the horse mtDNA mutation rate together with the archaeological timeframe for domestication requires at least 77 successfully breeding mares recruited from the wild. The extensive genetic diversity of these 77 ancestral mares leads us to conclude that several distinct horse populations were involved in the domestication of the horse.