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1.
Am J Hum Genet ; 110(5): 880-894, 2023 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-37105174

RESUMO

Using contemporary people as proxies for ancient communities is a contentious but necessary practice in anthropology. In southern Africa, the distinction between the Cape KhoeSan and eastern KhoeSan remains unclear, as ethnicity labels have been changed through time and most communities were decimated if not extirpated. The eastern KhoeSan may have had genetic distinctions from neighboring communities who speak Bantu languages and KhoeSan further away; alternatively, the identity may not have been tied to any notion of biology, instead denoting communities with a nomadic "lifeway" distinct from African agro-pastoralism. The Baphuthi of the 1800s in the Maloti-Drakensberg, southern Africa had a substantial KhoeSan constituency and a lifeway of nomadism, cattle raiding, and horticulture. Baphuthi heritage could provide insights into the history of the eastern KhoeSan. We examine genetic affinities of 23 Baphuthi to discern whether the narrative of KhoeSan descent reflects distinct genetic ancestry. Genome-wide SNP data (Illumina GSA) were merged with 52 global populations, for 160,000 SNPs. Genetic analyses show no support for a unique eastern KhoeSan ancestry distinct from other KhoeSan or southern Bantu speakers. The Baphuthi have strong affinities with early-arriving southern Bantu-speaking (Nguni) communities, as the later-arriving non-Nguni show strong evidence of recent African admixture possibly related to late-Iron Age migrations. The references to communities as "San" and "Bushman" in historic literature has often been misconstrued as notions of ethnic/biological distinctions. The terms may have reflected ambiguous references to non-sedentary polities instead, as seems to be the case for the eastern "Bushman" heritage of the Baphuthi.


Assuntos
Variação Genética , Genética Populacional , Humanos , África Austral , População Negra/genética , Etnicidade/genética
2.
Eur J Case Rep Intern Med ; 8(7): 002727, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34377705

RESUMO

Eosinophilic granuloma is a localized, non-invasive form of Langerhans cell histiocytosis. It usually develops in the long bones and is more frequent in children under the age of 10 years. It is very rare in adults. We present the case of a young woman admitted to hospital for persistent refractory left parietal headache, later revealed to be caused by an eosinophilic granuloma. LEARNING POINTS: Eosinophilic granuloma is a localized benign form of Langerhans cell histiocytosis.It is essential to exclude the presence of bone lesions in other locations and/or systemic involvement.The prognosis is good, with surgical resection, when necessary, being a curative intervention, although sometimes (as in this case) a conservative approach is sufficient.

3.
Eur J Case Rep Intern Med ; 8(4): 002554, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33987133

RESUMO

Proteus syndrome is an extremely rare disorder that manifests as an asymmetric, disproportionate overgrowth of any connective tissue, such as bone, fat or epidermal nevi, in a mosaic or patchy pattern. It has an estimated prevalence of less than 1/1,000,000 live births. The diagnosis can be difficult because the phenotypes of the patients are variable. Many individuals develop cutaneous capillary malformation and prominent varicosities (large and complex vascular malformations). Thus, Proteus syndrome patients are at risk of developing deep vein thrombosis and pulmonary embolism. The authors present the case of a patient with Proteus syndrome who was admitted because of pulmonary thromboembolism and presented hypertrophy of the left arm and left hemithorax. LEARNING POINTS: Proteus syndrome is an extremely rare disorder that manifests as an asymmetric, disproportionate overgrowth of any connective tissue.The diagnosis can be difficult because the phenotypes are variable.It is important to keep in mind the importance of anticoagulation because patients are at risk of developing deep vein thrombosis and pulmonary embolism.

4.
Curr Biol ; 29(23): 3974-3986.e4, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31735679

RESUMO

The human genetic diversity of the Americas has been affected by several events of gene flow that have continued since the colonial era and the Atlantic slave trade. Moreover, multiple waves of migration followed by local admixture occurred in the last two centuries, the impact of which has been largely unexplored. Here, we compiled a genome-wide dataset of ∼12,000 individuals from twelve American countries and ∼6,000 individuals from worldwide populations and applied haplotype-based methods to investigate how historical movements from outside the New World affected (1) the genetic structure, (2) the admixture profile, (3) the demographic history, and (4) sex-biased gene-flow dynamics of the Americas. We revealed a high degree of complexity underlying the genetic contribution of European and African populations in North and South America, from both geographic and temporal perspectives, identifying previously unreported sources related to Italy, the Middle East, and to specific regions of Africa.


Assuntos
Indígena Americano ou Nativo do Alasca/genética , População Negra/genética , Fluxo Gênico , Genoma Humano , População Branca/genética , Região do Caribe , América Central , Humanos , América do Norte , América do Sul
5.
Genetics ; 205(1): 303-316, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27838627

RESUMO

The characterization of the structure of southern African populations has been the subject of numerous genetic, medical, linguistic, archaeological, and anthropological investigations. Current diversity in the subcontinent is the result of complex events of genetic admixture and cultural contact between early inhabitants and migrants that arrived in the region over the last 2000 years. Here, we analyze 1856 individuals from 91 populations, comprising novel and published genotype data, to characterize the genetic ancestry profiles of 631 individuals from 51 southern African populations. Combining both local ancestry and allele frequency based analyses, we identify a tripartite, ancient, Khoesan-related genetic structure. This structure correlates neither with linguistic affiliation nor subsistence strategy, but with geography, revealing the importance of isolation-by-distance dynamics in the area. Fine-mapping of these components in southern African populations reveals admixture and cultural reversion involving several Khoesan groups, and highlights that Bantu speakers and Coloured individuals have different mixtures of these ancient ancestries.


Assuntos
População Negra/genética , DNA Antigo/análise , Estruturas Genéticas , África Austral , DNA Antigo/química , Frequência do Gene , Variação Genética , Genética Populacional/métodos , Genótipo , Haplótipos , Humanos , Lesoto , Namíbia , Filogeografia/métodos
6.
Genome Biol Evol ; 7(9): 2560-8, 2015 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-26363465

RESUMO

The expansion of Bantu-speaking agropastoralist populations had a great impact on the genetic, linguistic, and cultural variation of sub-Saharan Africa. It is generally accepted that Bantu languages originated in an area around the present border between Cameroon and Nigeria approximately 5,000 years ago, from where they spread South and East becoming the largest African linguistic branch. The demic consequences of this event are reflected in the relatively high genetic homogeneity observed across most of sub-Saharan Africa populations. In this work, we explored genome-wide single nucleotide polymorphism data from 28 populations to characterize the genetic components present in sub-Saharan African populations. Combining novel data from four Southern African populations with previously published results, we reject the hypothesis that the "non-Bantu" genetic component reported in South-Eastern Africa (Mozambique) reflects extensive gene flow between incoming agriculturalist and resident hunter-gatherer communities. We alternatively suggest that this novel component is the result of demographic dynamics associated with the Bantu dispersal.


Assuntos
Migração Humana , Polimorfismo de Nucleotídeo Único , África Subsaariana , Fluxo Gênico , Estudo de Associação Genômica Ampla , Humanos , Idioma
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