438 research outputs found
Multiplex genotyping system for efficient inference of matrilineal genetic ancestry with continental resolution
Abstract
Background: In recent years, phylogeographic studies have produced detailed knowledge on the worldwide
distribution of mitochondrial DNA (mtDNA) variants, linking specific clades of the mtDNA phylogeny with certain
geographic areas. However, a multiplex genotyping system for the detection of the mtDNA haplogroups of major
continental distribution that would be desirable for efficient DNA-based bio-geographic ancestry testing in various
applications is still missing.
Results: Three multiplex genotyping assays, based on single-base primer extension technology, were developed
targeting a total of 36 coding-region mtDNA variants that together differentiate 43 matrilineal haplo-/paragroups. These
include the major diagnostic haplogroups for Africa, Western Eurasia, Eastern Eurasia and Native America. The assays
show high sensitivity with respect to the amount of template DNA: successful amplification could still be obtained
when using as little as 4 pg of genomic DNA and the technology is suitable for medium-throughput analyses.
Conclusions: We introduce an efficient and sensitive multiplex genotyping system for bio-geographic ancestry
inference from mtDNA that provides resolution on the continental level. The method can be applied in forensics,
to aid tracing unknown suspects, as well as in population studies, genealogy and personal ancestry testing. For
more complete inferences of overall bio-geographic ancestry from DNA, the mtDNA system provided here can be
combined with multiplex systems for suitable autosomal and, in the case of males, Y-chromosomal ancestrysensitive
DNA markers
Unexpected Leiomyosarcoma 4 Years after Laparoscopic Removal of the Uterus Using Morcellation
Background. Laparoscopic hysterectomies are increasingly popular; a morcellation device is often used. Although there are some clear benefits, morcellation of tissue does have potential risks. Case Presentation. In this case report we present a 55-year-old woman with an abdominal tumour 4 years after a laparoscopic hysterectomy using a morcellation device. Postoperative histological analysis, compromised by morcellated tissue, showed benign myoma. Because of the benign tumour no follow-up was performed. The patient presented now with an abdominal tumour, and she was scheduled for surgical removal of the tumour. During abdominal surgery the tumour appeared malignant and biopsies were taken. Histological analysis showed leiomyosarcoma, and the patient was referred to a third care centre for further treatment. The patient recovered quickly after abdominal removal of the tumour; however, after 7 months the patient had complaints and a CT scan showed a large intra-abdominal tumour with possible lung metastasis. The patient received palliative chemotherapy and died after 10 months. Conclusion. This case shows that although unexpected after a hysterectomy, a leiomyosarcoma has to be considered in case of a suspect tumour in the lower abdomen
An efficient multiplex genotyping approach for detecting the major worldwide human Y-chromosome haplogroups
The Y chromosome is paternally inherited and therefore serves as an evolutionary marker of patrilineal descent. Worldwide DNA variation within the non-recombining portion of the Y chromosome can be represented as a monophyletic phylogenetic tree in which the branches (haplogroups) are defined by at least one SNP. Previous human population genetics research has produced a wealth of knowledge about the worldwide distribution of Y-SNP haplogroups. Here, we apply previous and very recent knowledge on the Y-SNP phylogeny and Y-haplogroup distribution by introducing two multiplex genotyping assays that allow for the hierarchical detection of 28 Y-SNPs defining the major worldwide Y haplogroups. PCR amplicons were kept small to make the method sensitive and thereby applicable to DNA of limited amount and/or quality such as in forensic settings. These Y-SNP assays thus form a valuable tool for researchers in the fields of forensic genetics and genetic anthropology to infer a man's patrilineal bio-geographic ancestry from DNA
A 12-month follow-up study of treating overweight schizophrenic patients with aripiprazole
Objective: To investigate the feasibility of switching overweight schizophrenic patients to aripiprazole and to assess the impact of 12 months of aripiprazole treatment on weight in routine practice. Method: This was a non-controlled cohort study in overweight schizophrenic patients. Data were collected before treatment with aripiprazole was started and at 12-month follow-up. Results: A total of 53 patients were included; of these 55% continued using aripiprazole for 12 months. Aripiprazole treatment for 12 months (P = 0.027) and stopping clozapine or olanzapine treatment (P = 0.038) predicted weight loss (>= 3 kg). Patients receiving aripiprazole monotherapy (n = 16, mean -3.0 kg) had similar weight loss than patients receiving aripiprazole in addition to another antipsychotic drug (n = 13, mean -4.4 kg). Conclusion: In routine practice once aripiprazole treatment was started, more than half of the patients remained on aripiprazole and most of them lost weight. Adding aripiprazole to clozapine gave similar weight loss as monotherapy with aripiprazole
Simultaneous Whole Mitochondrial Genome Sequencing with Short Overlapping Amplicons Suitable for Degraded DNA Using the Ion Torrent Personal Genome Machine
Whole mitochondrial (mt) genome analysis enables a considerable increase in analysis throughput, and improves the discriminatory power to the maximum possible phylo
A genetic contribution from the Far East into Ashkenazi Jews via the ancient Silk Road
Contemporary Jews retain a genetic imprint from their Near Eastern ancestry, but obtained substantial genetic components from their neighboring populations during their history. Whether they received any genetic contribution from the Far East remains unknown, but frequent communication with the Chinese has been observed since the Silk Road period. To address this issue, mitochondrial DNA (mtDNA) variation from 55,595 Eurasians are analyzed. The existence of some eastern Eurasian haplotypes in eastern Ashkenazi Jews supports an East Asian genetic contribution, likely from Chinese. Further evidence indicates that this connection can be attributed to a gene flow event that occurred less than 1.4 kilo-years ago (kya), which falls within the time frame of the Silk Road scenario and fits well with historical records and archaeological discoveries. This observed genetic contribution from Chinese to Ashkenazi Jews demonstrates that the historical exchange between Ashkenazim and the Far East was not confined to the cultural sphere but also extended to an exchange of genes
MtDNA population variation in Myalgic encephalomyelitis/Chronic fatigue syndrome in two populations: a study of mildly deleterious variants
Myalgic Encephalomyelitis (ME), also known as Chronic Fatigue Syndrome (CFS) is a debilitating condition. There is growing interest in a possible etiologic or pathogenic role of mitochondrial dysfunction and mitochondrial DNA (mtDNA) variation in ME/CFS. Supporting such a link, fatigue is common and often severe in patients with mitochondrial disease. We investigate the role of mtDNA variation in ME/CFS. No proven pathogenic mtDNA mutations were found. We then investigated population variation. Two cohorts were analysed, one from the UK (n = 89 moderately affected; 29 severely affected) and the other from South Africa (n = 143 moderately affected). For both cohorts, ME/CFS patients had an excess of individuals without a mildly deleterious population variant. The differences in population variation might reflect a mechanism important to the pathophysiology of ME/CFS
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