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F Rothhammer

Publications and source records attributed to F Rothhammer.

At least 19 recordsLinked to original sources
PubMed2000

Mitochondrial DNA polymorphisms in Chilean aboriginal populations: implications for the peopling of the southern cone of the continent.

The mitochondrial DNAs (mtDNAs) from individuals belonging to three Chilean tribes, the Mapuche, the Pehuenche, and the Yaghan, were studied both by RFLP analysis and D-loop (control region) sequencing. RFLP analysis showed that 3 individuals (1.3%) belonged to haplogroup A, 19 (8%) to haplogroup B, 102 (43%) to haplogroup C, and 113 (47.7%) to haplogroup D. Among the 73 individuals analyzed by D-loop sequencing, we observed 37 different haplotypes defined by 52 polymorphic sites. Joint analysis of data obtained by RFLP and sequencing methods demonstrated that, regardless of the method of analysis, the mtDNA haplotypes of these three contemporary South American aborigine groups clustered into four main haplogroups, in a way similar to those previously described for other Amerindians. These results further revealed the absence of haplogroup A in both the Mapuche and Yaghan as well as the absence of haplogroup B in the Yaghan. These results suggest that the people of Tierra del Fuego are related to tribes from south-central South America.

Base Sequence↗
PubMed2000

[Genetic composition of Chilean population: rural communities of Elqui, Limari and Choapa valleys].

BACKGROUND: The population that inhabits the semiarid Northern zone of Chile arose from ethnic admixture between aborigines, Spanish conquerors and the influx, during the XVII century, of foreign aboriginal workers and a minority of African slaves. AIM: To study the phenotypic frequencies of 15 genetic markers among populations inhabiting valleys in the Northern zone of Chile and to estimate the percentage of indigenous, African and Caucasian admixture in these populations. MATERIAL AND METHODS: Throughout five different field works, blood samples were obtained from 120 individuals living in the Elqui valley, 120 individuals living in the Limari valley and 85 living in the Choapa valley. Blood groups, erythrocyte enzymes, plasma proteins and HLA markers were typified. RESULTS: In the populations studied, the contribution of non indigenous genes was low in relation with the time elapsed since the Spanish invasion. The Hardy-Weinberg disequilibrium for MNS system would have microevolutive implications. The admixture percentages in these valleys confirm ethnic and historic information. The variation of the enzyme esterase D is identical to that of other Chilean populations. CONCLUSIONS: The phenotypic and genetic frequencies in the three populations studied and different admixture of indigenous genes is inversely proportional to the geographic distance from Santiago, in Central Chile.

Blood Group Antigens↗
PubMed1997

Origin of Amerindian Y-chromosomes as inferred by the analysis of six polymorphic markers.

We analysed the frequency of six Y-specific polymorphisms in 105 Amerindian males from seven different populations, 42 Caucasian males, and a small number of males of African, Chinese, and Melanesian origin. The combination of three of the six polymorphisms studied produced four different Y-haplogroups. The haplogroups A (non-variant) was the most frequent one. Eighty-five percent of Amerindians showing haplogroup A have the alphoid II (alpha hII) and the DYS19A Y-specific markers, an association that is found only in 10% of Caucasians and that has not been detected in Asiatics and Africans. Haplogroups C (YAP+) and D (YAP+ plus an A-->G transmission in the locus DYS271) are of African origin. Four percent of Amerindians and approximately 12% of Caucasians showed haplogroup C; approximately 1% of Amerindians and approximately 2% of Caucasians had haplogroup D. Haplogroup B is characterized by a C-->T transition in nucleotide position 373 of the SRY gene domain; this haplogroup is found in Caucasians (approximately 12%) and Amerindians (approximately 4%). None of the Amerindians exhibiting the haplogroups B, C, or D show the haplotype alpha hII/DYS19A. By haplotyping the the Alu insert and the DNA region surrounding the insert in YAP+ individuals, we could demonstrate that Amerindian Y chromosomes bearing African markers (haplogroups C and D) are due to recent genetic admixture. Most non-alpha hII/DYS19A Amerindian Y-chromosomes in haplogroup A and most cases in haplogroup B are also due to gene flow. We show that haplotype alpha hII/DYS19A is in linkage disequilibrium with a C-->T transition in the locus DYS19A. Our results suggest that most Amerindian Y-chromosomes derive from a single paternal lineage characterized by the alpha hII/DYS19A/DYS199T Amerindian-specific haplotype. The analysis of a larger sample of native American Y-chromosome will be required in order to confirm or correct this hypothesis.

Asian People↗
PubMed1995

Distribution of the four founding lineage haplotypes in Native Americans suggests a single wave of migration for the New World.

The distribution of the four founding lineage haplogroups in Native Americans from North, Central, and South America shows a north to south increase in the frequency of lineage B and a North to South decrease in the frequency of lineage A. All four founding lineage haplogroups were detected in North, Central, and South America, and in Greenberg et al.'s ([1986] Curr. Anthropol. 27:477-497) three major linguistic groups (Amerind, NaDene, and Eskaleut), with all four haplogroups often found within a single population. Lineage A was the most common lineage in North America, regardless of language group. This overall distribution is most parsimonious with a single wave of migration into the New World which included multiple variants of all four founding lineage types. Torroni et al.'s ([1993a] Am. J. Hum. Genet. 53:563-590) report that lineage B has a more recent divergence time than the other three lineages can best be explained by multiple variants of lineages A, C, and D, and fewer variants of lineage B entering the New World. Alternatively, there could have been multiple waves of migration from a single parent population in Asia/Siberia which repeatedly reintroduced the same lineages to the New World.

Americas↗
PubMed1995

[Major histocompatibility system as a risk factor for alcoholic liver disease].

Several associations between alleles of the major histocompatibility system and alcoholic liver disease have been described. However, these are weak and change from one population to another. The aim of this work was to search for a possible genetic risk factor for alcoholic liver disease among Chilean alcoholics. We studied blood groups, serum proteins and HLA antigens in 39 alcoholic cirrhotics, 104 asymptomatic alcoholics and 44 non alcoholic controls. Asymptomatic alcoholics were also subjected to a percutaneous liver biopsy that showed moderate to severe histological liver damage in 46 subjects (44%). No differences in the studied genetic markers, were found among the four groups. It is concluded that this study does not confirm previously reported associations between genetic markers and alcoholic liver disease.

Adult↗
PubMed1994

Genetic variation in the New World: ancient teeth, bone, and tissue as sources of DNA.

Examination of ancient and contemporary Native American mtDNA variation via diagnostic restriction sites and the 9-bp Region V deletion suggests a single wave of migration into the New World. This is in contrast to data from Torroni et al. which suggested two waves of migration into the New World (the NaDene and Amerind). All four founding lineage types are present in populations in North, Central, and South America suggesting that all four lineages came over together and spread throughout the New World. Ancient Native American DNA shows that all four lineages were present before European contact in North America, and at least two were present in South America. The presence of all four lineages in the NaDene and the Amerinds argues against separate migrations founding these two groups, although admixture between the groups is still a viable explanation for the presence of all four types in the NaDene.

Bone and Bones↗
PubMed1994

Population genetic characteristics of the D1S80 locus in seven human populations.

We have analyzed the allele frequency distribution at the highly polymorphic variable number of tandem repeat (VNTR) locus D1S80 (pMCT118) in seven ethnic populations (namely, New Guinea Highlanders of Papua New Guinea, Dogrib Indians of Canada, Pehuenche Indians of Chile, American and Western Samoans, Kacharis of Northeast India, and German Caucasians) using the polymerase chain reaction (PCR) technique. In the pooled sample of 443 unrelated individuals 20 segregating alleles were detected. A trimodal pattern of allelic distribution is present in the majority of populations and is indicative of the evolutionary antiquity of the polymorphism at this locus. In spite of the observed high degree of polymorphism (expected heterozygosity 56%-86%), with a single exception--the marginally significant P value (0.04) of the exact test in American Samoans--the genotype distributions in all populations conform to their respective Hardy-Weinberg expectations. Summary statistics indicate that, in general, the allele frequency distribution at this locus may be approximated by the infinite allele model. The data also demonstrate that alleles that are shared by all populations have the highest average frequency within populations. Furthermore, the kinship bioassay analysis demonstrates that the extensive variation observed at the D1S80 locus is at the interindividual within population level, which dwarfs any interpopulation allele frequency variation, consistent with the population dynamics of hypervariable polymorphisms. These characteristics of the D1S80 locus make it a very useful marker for population genetic research, genetic linkage studies, forensic identification of individuals, and for determination of biological relatedness of individuals.

Alleles↗
PubMed1994

Founder mitochondrial haplotypes in Amerindian populations.

It had been proposed that the colonization of the New World took place by three successive migrations from northeastern Asia. The first one gave rise to Amerindians (Paleo-Indians), the second and third ones to Nadene and Aleut-Eskimo, respectively. Variation in mtDNA has been used to infer the demographic structure of the Amerindian ancestors. The study of RFLP all along the mtDNA and the analysis of nucleotide substitutions in the D-loop region of the mitochondrial genome apparently indicate that most or all full-blooded Amerindians cluster in one of four different mitochondrial haplotypes that are considered to represent the founder maternal lineages of Paleo-Indians. We have studied the mtDNA diversity in 109 Amerindians belonging to 3 different tribes, and we have reanalyzed the published data on 482 individuals from 18 other tribes. Our study confirms the existence of four major Amerindian haplotypes. However, we also found evidence supporting the existence of several other potential founder haplotypes or haplotype subsets in addition to the four ancestral lineages reported. Confirmation of a relatively high number of founder haplotypes would indicate that early migration into America was not accompanied by a severe genetic bottleneck.

Americas↗
PubMed1994

[Genetic composition of the Chilean population: the Yamanas from Ukika].

The genetic composition of a group of 24 Yamana indians that survive in Puerto Williams, Navarino Island, Chile (parallel 55 south of Tierra del Fuego), was studied. Results showed that these indians have a different genetic composition than Pehuenche indians, specially for HLA system and esterase D. This fact validates the hypothesis, based on archeological and anthropological evidence, about the paleoindian origin of Yamanas.

Blood Group Antigens↗
PubMed1994

[Genetic composition of the Chilean population: the population from San Pedro de Atacama].

This work describes the genetic composition of atacameños from San Pedro de Atacama. The results show that a) the contribution of non-indigenous genes is relatively low, in relation to the spanish immigration period. b) the Hardy-Weinberg genetic disequilibrium for MNSs system should have biological implications c) the variant for esterasa D enzyme may be the same found in other chilean populations.

Blood Group Antigens↗
PubMed1994

[Alcoholism and heredity. A critical update].

The etiology of alcoholism is under constant revision. This work critically examines the accumulated evidence on the degree of genetic determination of alcoholism, aiming to provide an updated view of the problem. The methodological aspects of studies performed in families, twins and adopted siblings are analyzed. The associations of alcoholism with genetic markers and diseases are reviewed, including the negative correlation between alcoholism and an aldehyde dehydrogenase variant in Japanese subjects. The association between marker genes, specially the HLA system, with organic damage and the future projection of these studies are mentioned.

Alcoholism↗
PubMed1993

[Genetic composition of Chilean population: the Pehuenches from Trapa-Trapa].

This study describes the genetic composition of Pehuenche indians from Trapa-Trapa. The admixture analysis revealed that this group has conserved most of its pre-Columbian gene pool and therefore, is representative of the indians that lived in Southern Chile before the Spanish conquest. A relatively high frequency of a esterase D variant seems to indicate that this is a Chilean aboriginal population marker. The Chilean Pehuenches are genetically similar to their Argentinean relatives, which is not surprising since this last group crossed the Andes Mountains in historic times.

Blood Group Antigens↗
PubMed1992

[Paleodemography in mummies of prehispanic populations from Africa].

Mummies' demographic information of 10 prehispanic cultures that developed in the Arica region of Chile about 7000 years ago is analyzed and related to the present population structure. A paleoepidemiological analysis supports a relationship between cultural development and demographic structure. In chronological sequence, 4 demographic patterns can be distinguished: 1) archaic, a mature population with the highest life expectancy and the lowest dependence from prehispanic populations; 2) later archaic, a population in demographic explosion with its larger fraction under 15 years of age, elevated fertility rates and the greatest prehispanic dependence; 3) andean, a transition population with moderate fertility rates and dependence index; and 4) modern, an aging population with the highest proportion over 45 years of age and the highest life expectancy. The present demographic analysis may help to understand the relationships among disease, individual and culture from the perspective of genetic epidemiology.

Adolescent↗
PubMed1992

[Genetic evidence corroborates Negme's hypothesis about the greater mildness of American trypanosomiasis in Chile].

Chagas disease is present in northern and central Chile. Not more than 25% of infected individuals have had a pathologic condition presumably due to Trypanosoma cruzi. The majority of individuals with chronic infectious Chagas disease in Chile are asymptomatic in contrast to what has been observed in other South American countries. Historic and paleopathologic evidences suggest that this particular behavior could be explained by a genetic adaptation of Chilean aborigines to T cruzi. Associations between ethnic admixture, presence of Chagas disease, associated cardiac pathology and 4 blood groups (ABO, MNSs, Rh and Duffy) were investigated among inhabitants of San Pedro de Atacama in northern Chile. Cardiac pathology was determined by positive serologic reactions in individuals with abnormal electrocardiographic findings. Individuals with negative serologic results had a significantly greater aboriginal admixture (88%) compared to those with positive serology (66%). This findings supports the hypothesis of genetic adaptation explaining mildness of Chagas disease in Chile.

Adaptation, Physiological↗