PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 2998196

Dramatic founder effects in Amerindian mitochondrial DNAs.

D C Wallace·K Garrison·W C Knowler
View original source ↗Export metadata ↓

Abstract

Southwestern American Indian (Amerindian) mitochondrial DNAs (mtDNAs) were analyzed with restriction endonucleases and found to contain Asian restriction fragment length polymorphisms (RFLPs) but at frequencies very different from those found in Asia. One rare Asian HincII RFLP was found in 40% of the Amerindians. Several mtDNAs were discovered which have not yet been observed on other continents and different tribes were found to have distinctive mtDNAs. Since the mtDNA is inherited exclusively through the maternal lineage, these results suggest that Amerindian tribes were founded by small numbers of female lineages and that new mutations have been fixed in these lineages since their separation from Asia.

Explore related subjects

AsiaBlood PlateletsDNA Restriction EnzymesDNA, MitochondrialEthnicityGene FrequencyHumansIndians, North AmericanPhylogenyPolymorphism, GeneticUnited StatesComparative StudyJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

D C Wallace, K Garrison, W C Knowler. 1985. Dramatic founder effects in Amerindian mitochondrial DNAs.. https://doi.org/10.1002/ajpa.1330680202

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Reassortment of Highly Pathogenic Avian Influenza as a Driver for Zoonotic Spillover, Asia.

Highly pathogenic avian influenza H5Nx viruses remain a major zoonotic threat, yet global attention has focused largely on clade 2.3.4.4b, potentially overlooking major changes within long-endemic H5N1 lineages in Asia. Recent reports from South and Southeast Asia describe the emergence of reassortant clade 2.3.2.1 viruses alongside renewed human infections after apparent prolonged epidemiologic stability. Collectively, those events suggest a regional pattern rather than isolated anomalies. In this article, we argue that reassortment, rather than point mutation alone, might be an underrecognized driver of zoonotic risk in endemic H5N1 lineages and is reshaping those lineages. We examine why such events might be underrecognized in settings with entrenched poultry influenza, identify limitations of current surveillance systems, and call for integrated, real-time approaches linking genomic detection with phenotypic assessment across animal and human health sectors to enable timely risk assessment and coordinated public health action.

Asia↗
PubMed2026

Financing and health system capacity for precision medicine in Asia: a six country landscape analysis.

BACKGROUND: Precision medicine (PM) adoption is accelerating across Asia, but implementation remains uneven due to differences in financing, infrastructure, governance, and health-system readiness. OBJECTIVES: To examine how six Asian countries (Singapore, South Korea, China, Malaysia, Thailand, and Indonesia) adopt, finance, and integrate PM technologies, and identify common implementation patterns and challenges. METHODS: A landscape review of peer-reviewed literature, government publications, and HTA reports (2010-2026) was conducted, supplemented by stakeholder consultations. PM applications were grouped into public health screening (hereditary breast and ovarian cancer [HBOC] and familial hypercholesterolemia [FH] cascade testing), next-generation sequencing (NGS) applications (rare diseases, oncology, pharmacogenomics), and AI-enabled PM. Evidence was synthesized across access, awareness, reimbursement, and implementation. RESULTS: Public health genomic screening demonstrated the highest implementation readiness, followed by precision oncology, while rare disease diagnostics remained infrastructure-dependent and pharmacogenomics and AI-enabled PM platforms were at earlier stages. Four readiness profiles emerged: highly aligned systems; reimbursement-constrained systems with strong governance and infrastructure; systems strengthening governance, public financing and infrastructure; and strategy-led systems expanding implementation through pilot programs and referral centers. CONCLUSIONS: PM implementation across Asia remains heterogeneous. The identified readiness profiles highlight governance, financing, and infrastructure priorities for sustainable and equitable PM diffusion.

Asia↗
PubMed2026

Double heterozygous germline pathogenic variants in patients referred to a tertiary cancer genetics clinic in Singapore.

BACKGROUND: The increasing use of multigene panel testing has led to a rise in the identification of double heterozygous (DH) pathogenic variants in cancer patients, although their frequency and clinical relevance remain poorly characterised, particularly in Asian populations. METHODS: We conducted a retrospective review of 5,178 patients referred to a tertiary cancer genetics clinic in Singapore. DH pathogenic variants were defined as the presence of two or more distinct pathogenic or likely pathogenic germline variants identified by multigene panel testing. Clinical, pathological, and family history data were reviewed and analysed using appropriate non-parametric and exact statistical methods. RESULTS: Among 2,802 index patients with available genetic test results, 593 (21.2%) carried at least one pathogenic/likely pathogenic variant. DH pathogenic variants were identified in 21 individuals (0.75%), of which 9 were patients with breast cancer, 10 with non-breast malignancies, and 2 were cancer-free. The frequency of multiple primary cancers was 26.3% in DH variant carriers, 23.3% in single variant carriers, and 16.5% in those with no pathogenic variants. The median ages of first cancer diagnosis were 47, 44, and 48 years. Several DH combinations involved moderate- or low-penetrance genes, and some clinically unsuspected variants were detected only through broad multigene testing. CONCLUSION: DH pathogenic variants represent a rare subgroup that is increasingly detected through multigene panel testing. Their phenotypic expression is variable, and the influence of additional pathogenic variants remains uncertain. Our findings emphasise the need for tailored genetic evaluation and further research to guide evidence-based management for this complex patient population.

Asia↗