Early childhood growth of Chachi Amerindians and Afro-Ecuadorians in Northwest Ecuador

This study compares the growth of Chachi Amerindian and Afro-Ecuadorian children living in the tropical forest of northwest Ecuador. Measurements of height and weight were taken on 148 Chachi and 148 Afro-Ecuadorian children under 5 years of age. Triceps and subscapular skinfolds, arm circumference, chest circumference, and sitting height were measured on a subsample of children. Socioeconomic information was collected from the households of 145 children, and a general socioeconomic index was derived. Afro-Ecuadorian children are substantially taller than Chachi children, with significant differences in height for age z-scores in most age groups. On the other hand, Chachi children tend to have greater weight for height z-scores, with significant differences in some age groups. The greater weight for height of Chachi children may be related to their larger trunks. Estimates of body composition suggest that Afro-Ecuadorian children may have somewhat better nutritional status than Chachi children, but this does not appear to fully account for the greater height of Afro-Ecuadorian children. The socioeconomic index is positively correlated with all anthropometric dimensions, but even after controlling for the socioeconomic index, Afro-Ecuadorian children are significantly taller than Chachi children. These findings raise the possibility of genetic differences in growth potential between the two groups. © 1996 Wiley-Liss, Inc.     

Mysteries of the Amerindians

Several South, Central and North American Indian populations have been characterized over the past 9 years. A summary is given here. Very few major antigens have been found, namely A2, A9, A28 and Aw31 and B5, B15, Bw16, Bw35 and B40. However, several known splits of these antigens have been identified, and new variants are also likely. Immunogenetic analyses of the Amerindians should be able to provide clues both to the origins of the Amerindian cultures and migrations of early man, and also provide new insights into the antigens and the loci of the MHC.     

Influence of dietary quality on the growth of highland and coastal Ecuadorian children

This study examines variation in dietary patterns and its influence on physical growth among children under 60 months of age from rural households of highland and coastal Ecuador. Differences in subsistence ecology between the regions appear to influence infant and early childhood feeding patterns. Coastal children are weaned significantly earlier than their highland counterparts (median ± SE = 15.9 ± 1.7 vs. 24.7 ± 3.4 months) and have a weaning/supplemental diet that contains significantly more animal foods. In both regions, growth retardation is most severe among infants (<12 months), with growth rates being poorer in the highlands than on the coast. Linear growth rates among coastal infants are positively correlated with intakes of animal energy and animal protein, whereas among highland children energy intake from supplemental/weaning foods is negatively correlated with linear growth. These divergent patterns appear to be a consequence of the differences in nutrient density of the weaning/supplemental diets. Among the coastal infants, higher quality, nutrient dense foods augment breast milk and contribute to better growth rates. In contrast, among the highland infants the more filling, less nutrient dense foods appear to be replacing breast milk, and thus compromising growth status. In the older cohorts (i.e., “weaning age” children: 12.0–35.9 months, and completely weaned children: 36.0–59.9 months), linear growth rates stabilize with little evidence of “catch up” growth in either region. Improved weight gain, however, is seen among the highland children, and is correlated with the nutritional intake (i.e., energy, total protein, and animal protein) from weaning foods. Overall, marked growth stunting is seen in both regions, but is more pronounced in the highland children. These high levels of stunting are largely established in the first 12 months of life. Greater growth retardation among the highland children appears to reflect the influence of hypoxia as well as the lower nutrient density of weaning foods in that region. Am. J. Hum. Biol. 12:825–837, 2000. © 2000 Wiley-Liss Inc.     

HLA-DP polymorphism in Venezuelan Amerindians

Three different Venezuelan Amerindian tribes were studied for human leukocyte antigen (HLA)-DPA1 and DPB1 allelic variability using polymerase chain reaction–sequence-specific oligonucleotide probes (PCR-SSOP) and sequence-based typing in a selected group of samples. These tribes are geographically (two from the Perija Mountain range and one from the Orinoco Delta) and linguistically distinct: the Bari (from Campo Rosario and Saymaidoyi villages) and the Warao have been classified within the Chibcha linguistic family, whereas the Yucpa (from the Aroy, Marewa, and Peraya villages) are Carib speaking. Venezuelan Indians, like other Native American tribes, show a markedly reduced number of different HLA-DP alleles (range, 2–7) and haplotypes (range, 4–11) in comparison with neighboring Venezuelan mestizo and other non-Indian populations. Some HLA-DPB1 (*0402 and *1401) alleles characteristic for all Amerindian tribes are present also in these populations. Despite general similarities, each tribe and, in some cases, some subtribes show their own pattern of allele and haplotype distribution apparently more as a result of linguistic than to geographic variation.     

Facial morphometry of Ecuadorian patients with growth hormone receptor deficiency/Laron syndrome.

Facial morphometry using computerised image analysis was performed on patients with growth hormone receptor deficiency (Laron syndrome) from an inbred population of southern Ecuador. Morphometrics were compared for 49 patients, 70 unaffected relatives, and 14 unrelated persons. Patients with growth hormone receptor deficiency showed significant decreases in measures of vertical facial growth as compared to unaffected relatives and unrelated persons with short stature from other causes. This report validates and quantifies the clinical impression of foreshortened facies in growth hormone receptor deficiency.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

HLA genes in Lamas Peruvian-Amazonian Amerindians

The Lamas Amerindians are the Chancas descents who established before 1532 a.d. (Spanish conquest) at Lamas City, Wayku quarter in a Peruvian-Amazonian province (San Martin). The Lamas HLA profile shows significant differences with other Amerindians HLA profile, i.e.: (a) a higher number of newly found haplotypes compared to other studied Amerindian populations, particularly HLA-A*02-B*48-DRB1*0403-DQB1*0302, A*02-B*48-DRB1*0804-DQB1*0402 and A*02-B*40-DRB1*0407-DQB1*0302; (b) a relative high frequency of HLA-DRB1*0901 (a high frequency southern Asian allele) and HLA-B*48 (a Na-Dene, Siberian and Eskimo allele); both alleles are also found frequently in Quechuas and Aymaras, but not in many other (particularly Meso American) Amerindians and (c) correspondence and neighbor-joining dendrogram analyses show that Lamas (Chancas) may have an origin close to Amazonian Indians that later reached the Andean altiplano.     

HLA genes in Wayu Amerindians from Colombia

Amerindians origins and prehistory are still debated. HLA profile is different to all other World populations, although they have particular alleles in common with Asians, Australians and Pacific Islanders. In the present work, HLA-A, -B, -DRB1, -DQB1 alleles have been studied in Wayu Amerindians from Colombia. HLA alleles haplotypes, genetic distances and NJ dendrograms were calculated by Arlequin and DISPAN software. Only a few both class I and class II alleles have been observed. Most common extended haplotypes include: A*24-B*51-DRB1*0403-DQB1*0302, A*2-B*15-DRB1*1602-DQB1*0301, A*2-B*35-DRB1*0407-DQB1*0302, but also A*68-B*15-DRB1*0403-DQB1*0302. No trace of Caucasoid or Negroid admixture is detected. The Wayu HLA profile is typical from Amerindians and shows how languages and genes do not correlated particularly in this case (i.e., Wayu closest HLA genetic group is North Argentinian Guarani group). Results obtained in this work may be useful for future transplant programs and also for HLA linked diseases and individualized pharmacogenetics.     

Heterogeneity of Y chromosome markers among Brazilian Amerindians

The allele frequency distribution of DYS19 and DYS199 loci were analyzed in 59 Brazilian Amerindians from five tribes from the Amazon region (Zoé, Awá-Guajá, Urubú-Kaapór, Katuena, and Kayapó, Xikrin of Bacajá village). Three different alleles of the DYS19 microsatellite (182-bp, 186-bp, and 190-bp) were found at average frequencies of 0.08, 0.85, and 0.07, respectively. The DYS199-T allele was identified in 78% of the Amerindians studied (43/55), the frequencies varying from 0.46–0.93. Four different haplotypes were found, the combination DYS19–186/DYS199-T being the most common (average frequency of 0.65), followed by DYS19–186/DYS199-C with an average frequency of 0.22. These four haplotypes have been found in five other Brazilian tribes, and most of them were also identified in Native populations from South, Central and North America. The observed variability at the DYS19 microsatellite is probably due to forward or back mutations from the putative ancestral 186-bp allele, since the mutation rate of this locus is high and the post-Columbian admixture of the Brazilian tribes studied is very low or undetectable to explain these data. On the other hand, the DYS19/DYS199 haplotype distribution may suggest that the two most common haplotypes (186-bp/T and 186-bp/C) were present among the population(s) that peopled the New World. Am. J. Hum. Biol. 11:481–487, 1999. © 1999 Wiley-Liss, Inc.     

HLA class I diversity in Kolla Amerindians

Human leukocyte antigen (HLA) class I polymorphism was studied within a population of 70 unrelated Kolla Amerindians from the far northwest of Argentina close to the Bolivian border. The results indicate that the HLA-A, -B, and -C alleles typical of other Amerindian populations also predominate in the Kolla. These alleles belong to the following allele groups: HLA-A*02, *68, *31, *24, HLA-B*35, *15, *51, *39, *40, *48, and Cw*01, *03, *04, *07, *08, and *15. For the HLA-A locus, heterogeneity was seen for HLA-A*02 with A*0201, *0211, and *0222; and for A*68 with *68012 and *6817, the latter being a novel allele identified in this population. Analysis of HLA-B identified heterogeneity for all Amerindian allele groups except HLA-B*48, including the identification of the novel B*5113 allele. For HLA-C heterogeneity was identified within the Cw*07, *04, and *08 groups with Cw*0701/06, *0702, *04011, *0404, *0803, and *0809 identified. The most frequent "probable" haplotype found in this population was B*3505-Cw*04011. This study supports previous studies, which demonstrate increased diversity at HLA-B compared with HLA-A and -C. The polymorphism identified within the Kolla HLA-A, -B, and -C alleles supports the hypothesis that HLA evolution is subject to positive selection for diversity within the peptide binding site.     

HLA genes in Wayu Amerindians from Colombia

Amerindians origins and prehistory are still debated. HLA profile is different to all other World populations, although they have particular alleles in common with Asians, Australians and Pacific Islanders. In the present work, HLA-A, -B, -DRB1, -DQB1 alleles have been studied in Wayu Amerindians from Colombia. HLA alleles haplotypes, genetic distances and NJ dendrograms were calculated by Arlequin and DISPAN software. Only a few both class I and class II alleles have been observed. Most common extended haplotypes include: A*24-B*51-DRB1*0403-DQB1*0302, A*2-B*15-DRB1*1602-DQB1*0301, A*2-B*35-DRB1*0407-DQB1*0302, but also A*68-B*15-DRB1*0403-DQB1*0302. No trace of Caucasoid or Negroid admixture is detected. The Wayu HLA profile is typical from Amerindians and shows how languages and genes do not correlated particularly in this case (i.e., Wayu closest HLA genetic group is North Argentinian Guarani group). Results obtained in this work may be useful for future transplant programs and also for HLA linked diseases and individualized pharmacogenetics.     

ABO blood group in Amerindians from Brazilian Amazon

Background : The Parakanã is a group of Indians with cultural similarities to the extinct Tupi group. They are an isolated native population from East Brazilian Amazon. A number of different O alleles have been found at the blood group ABO locus in populations of several ethnic origins (Caucasians, Blacks, Amerindians). Aim : The present study describes the ABO blood group polymorphism gene of the Parakanã Indians. The Amerindian group was carefully selected for racial background. Subject and methods : The blood group polymorphism was analysed in genomic DNA from 62 Parakanã Indians. We determined the 261G deletion, the T646A and C771T mutations described in O 1variant and the G542A substitution, using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism). Results : All Amerindians studied were homozygous for the 261G deletion. The frequencies of the T646A and C771T mutations in Parakanãs (0.65) were lower than that observed in Kayapo, Yanomama and Arara Indians (0.91) ( &#104 2 = 18.24; p-v < 0.001. The G542A substitution in Parakanãs was also lower (0.22) than in other tribes (0.42) ( &#104 2 = 9.73; p-v = 0.001). Conclusions : The different O alleles including the G542A mutation are not distributed homogeneously among all Amazonian Amerindians. Our results are in agreement with other genetic markers studied previously in Parakanã Indians, whose distinct genetic pattern differs from Europeans and even from other Amerindians.     

ABO blood group in Amerindians from Brazilian Amazon

BACKGROUND: The Parakan? is a group of Indians with cultural similarities to the extinct Tupi group. They are an isolated native population from East Brazilian Amazon. A number of different O alleles have been found at the blood group ABO locus in populations of several ethnic origins (Caucasians, Blacks, Amerindians). AIM: The present study describes the ABO blood group polymorphism gene of the Parakan? Indians. The Amerindian group was carefully selected for racial background. SUBJECT AND METHODS: The blood group polymorphism was analysed in genomic DNA from 62 Parakan? Indians. We determined the 261G deletion, the T646A and C771T mutations described in O(1variant) and the G542A substitution, using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism). RESULTS: All Amerindians studied were homozygous for the 261G deletion. The frequencies of the T646A and C771T mutations in Parakan?s (0.65) were lower than that observed in Kayapo, Yanomama and Arara Indians (0.91) (chi (2) = 18.24; p-v < 0.001. The G542A substitution in Parakan?s was also lower (0.22) than in other tribes (0.42) (chi(2) = 9.73; p-v = 0.001). CONCLUSIONS: The different O alleles including the G542A mutation are not distributed homogeneously among all Amazonian Amerindians. Our results are in agreement with other genetic markers studied previously in Parakan? Indians, whose distinct genetic pattern differs from Europeans and even from other Amerindians.     

Patterns and correlates of genetic variation in South Amerindians

Gene frequency data from six polymorphic blood group systems in 70 South American Indian populations are used to derive synthetic gene frequency maps that document the geographical pattern of genetic variation. Additional analyses are directed toward the elucidation of mechanisms that give rise to or maintain the observed distributions. Variables of local ecology do not appear to explain gene frequency distributions in South America. Instead, local isolation and the action of stochastic forces appears to be the most parsimonious explanation of the observed geographical patterns. This is distinctly different from the geographical patterns of genetic variation seen in other continents.     

智力低下儿童的体格生长

为了解智力低下儿童的体格生长情况，对326名患儿进行了智力、身高、体重、头围和骨龄的测试，结果表明智力低下儿童平均体格生长水平低于正常儿童。虽然智力与生长间未显示出明显的线性关系，但生长迟缓和小头畸形见于严重的智力低下儿。骨龄与智力水平未见显著相关。     

Physical growth in Brachmann-de Lange syndrome

Growth in 30 patients with Brachmann-de Lange syndrome (BDLS) was evaluated and found to be deficient in 27/30, with 17/27 having intrauterine growth retardation (IUGR). In 12/27 Patients, endocrine evaluations have been completed. Seven of 12 were normal and 4/12, one with empty sella, had “classical” growth hormone deficiency with extreme short stature, markedly delayed skeletal maturation and subnormal growth hormone secretion in response to provocative stimuli. One of 12 patients had discordance between insulin growth factor I levels and growth hormone responses to insulin and clonidine suggestive of end organ resistance to growth harmone. It appears that the hypothalmamic-pituitary function is compromised in at least some BDLS patients. Thus, endocrine evaluations are warranted for the patients with short stature. © 1993 Wiley-Liss, Inc.     

New genetic data on Amerindians from the Paraguayan Chaco

New data on 17 blood group and protein genetic systems obtained among the Ayoreo and Lengua Indians of Paraguay are presented. They include the first report on the red cell band‐3 protein investigated among South American Indians. This information was integrated with previous results available for these two and four other groups. Five of the six populations reside in the Chaco area, while the sixth was included as an outgroup living elsewhere in Paraguay. Four of the five Chaco tribes exhibit good genetic homogeneity, but the Ayoreo are somewhat different. The results confirm the Chaco as a distinct biological (as well as cultural and economic) region, which should be considered in evaluations of genetic variability among South American Indians. Am. J. Hum. Biol. 13:660–667, 2001. © 2001 Wiley‐Liss, Inc.