J E Bernal

Pontifical Xavierian University (Bogota), Bogotá, Bogota D.C., Colombia

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Publications (30)60.64 Total impact

  • J E Bernal, I Briceno
    Case Reports 02/2009; 2009:bcr2007133678.
  • J E Bernal, I Briceño
    Archivos de la Sociedad Espanola de Oftalmologia 12/2008; 83(11):679-80.
  • J E Bernal, I Briceno
    Archives of Disease in Childhood - Fetal and Neonatal Edition 06/2008; 93(3):F245. · 3.86 Impact Factor
  • J. E. Bernal, I. Briceño
    Archivos de la Sociedad Espanola de Oftalmologia 01/2008; 83(11).
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    ABSTRACT: We examined mitochondrial DNA (mtDNA) haplogroup and haplotype diversity in 188 individuals from three Chibchan (Kogi, Arsario, and Ijka) populations and one Arawak (Wayuú) group from northeast Colombia to determine the biological relationship between lower Central American and northern South American Chibchan speakers. mtDNA haplogroups were obtained for all individuals and mtDNA HVS-I sequence data were obtained for 110 samples. Resulting sequence data were compared to 16 other Caribbean, South, and Central American populations using diversity measures, neutrality test statistics, sudden and spatial mismatch models, intermatch distributions, phylogenetic networks, and a multidimensional scaling plot. Our results demonstrate the existence of a shared maternal genetic structure between Central American Chibchan, Mayan populations and northern South American Chibchan-speakers. Additionally, these results suggest an expansion of Chibchan-speakers into South America associated with a shift in subsistence strategies because of changing ecological conditions that occurred in the region between 10,000-14,000 years before present.
    American Journal of Physical Anthropology 06/2007; 133(1):753-70. · 2.51 Impact Factor
  • J E Bernal, I Briceno
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    ABSTRACT: The people of Tumaco-La Tolita culture inhabited the borders of present-day Colombia and Ecuador. Already extinct by the time of the Spaniards arrival, they left a huge collection of pottery artifacts depicting everyday life; among these, disease representations were frequently crafted. In this article, we present the results of the personal examination of the largest collections of Tumaco-La Tolita pottery in Colombia and Ecuador; cases of Down syndrome, achondroplasia, mucopolysaccharidosis I H, mucopolysaccharidosis IV, a tumor of the face and a benign tumor in an old woman were found. We believe these to be among the earliest artistic representations of disease.
    Clinical Genetics 10/2006; 70(3):188-91. · 3.65 Impact Factor
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    ABSTRACT: Homocystinuria is an autosomal recessive disease most commonly caused by mutations in cystathionine beta-synthase (CBS). In this study we present the mutation analysis of 36 Colombian individuals from 10 unrelated kindred, with 11 individuals clinically classified as homocystinuric. Mutation analysis of the CBS gene revealed p.T191M, a prevalent mutation in Spain and Portugal, in the homozygous state in seven of the unrelated patients. Genotype-phenotype assessment of the p.T191M homozygous patients showed a high level of variability, including different severity in one pair of affected siblings. None of the patients responded biochemically to treatment with pharmacological doses of pyridoxine and folic acid as revealed by essentially unchanged homocysteine levels. This study offered a unique opportunity to study 18 heterozygous (p.T191M/wt) relatives of the homocystinuric patients. One atypical finding was that many of them presented with above average total homocysteine levels, putting them at an increased risk for vascular disease. Cryptorchidism was present in three of the cases, one of which presented also with Klinefelter syndrome. In addition to the previously described p.T191M mutation, a new mutation, p.A288T, was identified in a single individual. In this paper we present the first characterization, at a molecular level, of patients with homocystinuria from Colombia.
    Human Mutation 03/2006; 27(3):296. · 5.05 Impact Factor
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    ABSTRACT: Classical homocystinuria is due to cystathionine beta-synthase (CBS) deficiency. More than 130 mutations, which differ in prevalence and severity, have been described at the CBS gene. Mutation p.I278T is very prevalent, has been found in all European countries where it has been looked for with the exception of the Iberian peninsula, and is known to respond to vitamin B6. On the other hand, mutation p.T191M is prevalent in Spain and Portugal and does not respond to B6. We analysed 30 pedigrees from Spain, Portugal, Colombia and Argentina, segregating for homocystinuria. The p.T191M mutation was detected in patients from all four countries and was particularly prevalent in Colombia. The number of p.T191M alleles described in this study, together with those previously published, is 71. The prevalence of p.T191M among CBS mutant alleles in the different countries was: 0.75 in Colombia, 0.52 in Spain, 0.33 in Portugal, 0.25 in Venezuela, 0.20 in Argentina and 0.14 in Brazil. Haplotype analyses suggested a double origin for this mutation. No genotype-phenotype correlation other than the B6-nonresponsiveness could be established for the p.T191M mutation. Additionally, three new mutations, p.M173V, p.I429del and c.69_70+8del10, were found. The p.M173V was associated with a mild, B6-responsive, phenotype.
    Journal of Human Genetics 02/2006; 51(4):305-13. · 2.53 Impact Factor
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    ABSTRACT: We report the frequencies of alleles at the microsatellite locus D12S67 in 2 widely separated ethnic groups of the world: 2 populations from Sulawesi, an island in the Indonesian archipelago, and 5 Native American tribes of Colombia, South America. The allele frequencies in the Minihasans and Torajans of Sulawesi are similar to each other (but the modal class allele is different) and in general agreement with those reported in mainland Asian groups, but different from both Europeans and Chinese Han of Taiwan. The 5 Native American tribes (Arsario, Kogui, Ijka, Wayuu, and Coreguaje) display different allele frequencies from those seen in Sulawesi populations, in other groups from Europe and mainland Asia, and in Chinese Han of Taiwan. Native Americans exhibit a bimodal distribution of alleles, unlike other groups, with significant differences among the tribes. The Arsario and Kogui have no admixture with Europeans or Africans and are the most distinctive, while the Wayuu have the most admixture and show most similarity to other groups. The data suggest that nonadmixed Native Americans may be quite distinctive with respect to this marker. The most common allele varies across the 5 tribes, from 249 base pairs to 261 base pairs. All samples exhibit Hardy-Weinberg genotype proportions; heterozygosities are lowest in the 2 nonadmixed Native American tribes. Examination of all the available data indicates that some east Asian and southeast Asian groups are characterized by a high frequency of smaller sized D12S67 alleles, while other populations have a greater proportion of the larger sized alleles. The cumulative, though still highly restricted, population data on locus D12S67 demonstrate that it may be of considerable value in anthropological genetic studies of ethnic groups. Data are required on Native Americans outside Colombia before this marker can be used in admixture studies of this group.
    Human Biology 09/2000; 72(4):697-705. · 1.52 Impact Factor
  • Diabetes Care 09/1996; 19(8):900-1. · 8.57 Impact Factor
  • I Briceno, A Gomez, J E Bernal, S S Papiha
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    ABSTRACT: HLA-DPB1 allele frequencies were investigated in seven geographically and linguistically distinct Amerindian tribes of Colombia. Allele *1301 was found only in the Embera tribe living along the Pacific coast, while allele *0101 was found only in two individuals of the Wayuu tribe inhabiting the Guajira desert. Significant geographical variation was observed in the other two alleles (*1401 and *0402), which were found in all seven tribal groups. The possible reasons for this restricted polymorphism and the genetic diversity found in the investigation are discussed.
    European Journal of Immunogenetics 07/1996; 23(3):235-40.
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    I. Briceno, A. Gomez, J. E. Bernal, S. S. Papiha
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    ABSTRACT: SUMMARYHLA-DPB 1 allele frequencies were investigated in seven geographically and linguistically distinct Amerindian tribes of Colombia. Allele *1301 was found only in the Embera tribe living along the Pacific coast, while allele *0101 was found only in two individuals of the Wayuu tribe inhabiting the Guajira desert. Significant geographical variation was observed in the other two alleles (*1401 and *0402), which were found in all seven tribal groups. The possible reasons for this restricted polymorphism and the genetic diversity found in the investigation are discussed.
    International Journal of Immunogenetics 05/1996; 23(3):235 - 240. · 1.34 Impact Factor
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    ABSTRACT: Serological HLA types (A, B, C, DR and DQ loci) were studied in five different Indian tribes (Cubeo, Tucano, Coreguaje, Embera and Noanama) belonging to two distinct linguistic families. For all the MHC loci, the range of variation among the five tribes was enormous. Two tribes, Cubeo and Tucano, showed a wide spectrum of antigenic specificities which seemed to be due to admixture from non-tribal groups, while in the other three tribes the polymorphisms of various HLA loci showed restricted distributions. The gene frequency data, when converted to a kinship matrix and a two-dimensional eigenvector plot, indicated that members of the same linguistic family tend to have greater genetic affinity.
    European Journal of Immunogenetics 03/1996; 23(1):21-8.
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    ABSTRACT: Serological HLA types (A, B, C, DR and DQ loci) were studied in five different Indian tribes (Cubeo, Tucano, Coreguaje, Embera and Noanama) belonging to two distinct linguistic families. For all the MHC loci, the range of variation among the five tribes was enormous. Two tribes, Cubeo and Tucano, showed a wide spectrum of antigenic specificities which seemed to be due to admixture from non-tribal groups, while in the other three tribes the polymorphisms of various HLA loci showed restricted distributions. The gene frequency data, when converted to a kinship matrix and a two-dimensional eigenvector plot, indicated that members of the same linguistic family tend to have greater genetic affinity.
    International Journal of Immunogenetics 02/1996; 23(1):21-28. · 1.34 Impact Factor
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    ABSTRACT: Blood samples of 1.022 individuals of both sexes, collected during the “Expedicion Humana” programme. Twelve Indian group, two Negroes, two urban and one mestizo populations of Colombia were C3 typed. The results showed the urban samples have C3*F genotype frequencies (17 and 20%) similar to the Spanish population. The Negroe system, with lower C3*F gene frequencies (3.5 and 7%) also resembled their parental populations in Africa. The Mestizo population reported in this study showed a lower value of the C3*F gene (2.2%) than previously studied. suggesting that the degree of admixture may vary in different regions of the country. As regards the Indian populations, there was a wide range of variation of the C3*F gene (0–19%) many tribes being monomorphic. This gene may be a marker of recent admixture in Amerindians, but there may be other genetic factors, such as selection and inbreeding in maintaining high levels of genetic polymorphism in tribes such as Guahibo.
    International Journal of Anthropology 10/1995; 10(4):203-208.
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    ABSTRACT: The serological HLA types (A,B,C and D loci) were studied in the Sikuani and Guayabero, two Guahiboan speaking Indian groups inhabiting the eastern lowlands of Colombia. Besides restricted polymorphism, the results show significant differences only in two antigens, A2 and B35, suggesting genetic similarity among these tribes which belong to the same linguistic family. Genetic distances were calculated for comparison with other Colombian groups so far studied, showing the lowest distance between the two tribes under study. The Guayabero were closer to the urban population of Bogota, which suggests that the genetic structure of the present day Amerindians of South America may be significantly influenced by the European populations.
    International Journal of Anthropology 01/1995; 10(4):209-212.
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    ABSTRACT: The serological HLA types (A, B, C and D loci) were studied in five different Indian groups in Colombia. The range of polymorphism was not very restricted in these groups, but there was significant genetic heterogeneity among the five populations in all the HLA loci. The gene frequency data, when converted into a kinship matrix and a two-dimensional eigen vector plot, showed a closer affinity between Bari and Yuko Indians, while Guane, Tunebo and Paez Indians were not only genetically different from the former but also well-differentiated from each other. It seems therefore from this study that geographical proximity may play a greater role than linguistic similarities in the genetic affinities of Colombian Amerindians.
    Human Heredity 01/1995; 45(4):186-91. · 1.64 Impact Factor
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    ABSTRACT: Haptoglobin subtypes were analysed by isoelectric focusing in four populations from Colombia, England, Nigeria, and India. There is a wide range of variation of allele frequencies in these four populations: HP*1S = 15-28%, HP*1F = 5-19%, HP*2FS = 54-79%. With the exception of the English, and the Spanish-speaking population of Colombia, all interpopulation comparisons showed significant heterogeneity. There is an extreme variation for the HP*1F allele in different populations, and a possible geographical cline of the HP*2FS allele increasing from west to east. The data presented here suggest that HP subtypes provide a useful anthropogenetic marker for racial differentiation.
    Human Heredity 01/1994; 44(1):10-3. · 1.64 Impact Factor
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    ABSTRACT: The coexistence of infection with human T lymphotropic virus types I and II (HTLV-I and HTLV-II) has been demonstrated recently among the Wayuu Indians from the Guajira region of Colombia. To ascertain if other Indian groups in Colombia are similarly infected, we tested 1,250 sera, collected between 1990 and 1992 from 18 culturally distinct Amerindian tribes living in widely separated regions, for IgG antibodies against HTLV-I/II using enzyme-linked immunosorbent assay (ELISA) and Western blot. Sera were also tested for antibodies against human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) to investigate the overall burden of retrovirus infection in these semi-isolated indigenous groups. A total of 33 of the 1,250 samples were repeatedly reactive to HTLV-I/II antigens by ELISA, and of these, three sera from Waunana/Noanama Indians from the Choco area and two sera from Tunebo Indians from the Santander region were found to be infected with HTLV-I and HTLV-II, respectively, as verified by Western blot and differential ELISA. Thus, despite the small sample size, the overall seroprevalences for HTLV-I and HTLV-II infection among the Waunana/Noanama and Tunebo Indians were 2.1% and 5.0%, respectively. In contrast, none of the 29 Indians who exhibited reactivity to HIV-1/2 by ELISA were seropositive by Western blot. This study adds the Tunebo to the expanding list of Amerindian groups with high prevalences of HTLV-II infection. Further intensive investigations of such indigenous populations will clarify the natural history and disease potential of HTLV-II infection.
    The American journal of tropical medicine and hygiene 01/1994; 49(6):657-63. · 2.74 Impact Factor
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    ABSTRACT: High prevalences of human T-lymphotropic virus type II (HTLV-II) infection have been found recently among certain Amerindian groups in North, Central, and South America. To determine if the Amerindians of Colombia are similarly affected, 523 sera, collected between 1987 and 1990 from nine culturally distinct Indian groups from widely separated regions, were tested for IgG antibodies against HTLV-I/II using enzyme-linked immunosorbent assay (ELISA) and Western blot. In addition, 243 sera from five non-Indian (black) and mixed-Indian (mestizo) populations were studied. Of the 766 individuals tested, 44 were ELISA positive, but of these, only four were Western blot positive. Three of the individuals confirmed positive by Western blot were infected with HTLV-II and one was infected with HTLV-I, as determined by differential ELISA. All four seropositive individuals belonged to a group of 62 Wayuu Indians, giving overall HTLV-I and HTLV-II seroprevalences of 1.6% and 4.8%, respectively. The coexistence of HTLV-I and HTLV-II in this Amerindian group provides an opportunity to study the factors governing transmission of these retroviruses.
    AIDS Research and Human Retroviruses 12/1992; 8(11):1851-5. · 2.46 Impact Factor

Publication Stats

208 Citations
60.64 Total Impact Points

Institutions

  • 1988–2009
    • Pontifical Xavierian University (Bogota)
      • • Institute for Human Genetics
      • • School of Medicine
      Bogotá, Bogota D.C., Colombia
  • 2000
    • La Trobe University
      Melbourne, Victoria, Australia
  • 1996
    • Newcastle University
      Newcastle-on-Tyne, England, United Kingdom
  • 1994
    • Loughborough University
      Loughborough, England, United Kingdom