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J E Bernal

Publications and source records attributed to J E Bernal.

At least 19 recordsLinked to original sources
PubMed2006

Genetic and other diseases in the pottery of Tumaco-La Tolita culture in Colombia-Ecuador.

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.

Colombia↗
PubMed2000

Further data on the microsatellite locus D12S67 in worldwide populations: an unusual distribution of D12S67 alleles in Native Americans.

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.

Base Pairing↗
PubMed1997

Social, familial and medical aspects of Usher syndrome in Colombia.

A psycho-social study was performed in 19 Colombian families with 40 affected individuals with Usher syndrome, identified through our national screening program for this disease in Colombia. The study was aimed to understand their needs, kind of familial inter-relationships, and social and familial implications of the patients' double sensorial limitation, in order to provide enough information to support the importance of early diagnosis, appropriate genetic counseling, and the establishment of adequate educational and rehabilitation programs in Colombia.

Adolescent↗
PubMed1996

New allele variants of the immunoglobulin switch (Salpha) regions.

In this report we define ten Salpha1 IGHA1 (*S5-*S14) and nine Salpha2 IGHA2 (*S10-*S18) newly found alleles of the human immunoglobulin switch alpha 1 and switch alpha 2 regions, respectively, in Colombian Indian, Black and Mestizo populations, and a complete list of the SacI and PvuII alleles so far identified as given.

Alleles↗
PubMed1996

Neuroradiology and clinical aspects of Usher syndrome.

We describe the neurological evaluation and MRI analysis of 30 patients, belonging to 16 families with Usher syndrome (US) type I and type II (US1 and US2). In addition to the classic visual and audiological abnormalities seen in these patients, we observed abnormal gait in 88.9% of US1 and in 66.7% of US2 patients and abnormal coordination in 33.4% of US1, and in 58.3% of US2. Borderline mental retardation, depression or bipolar affective disorder were observed in 16.7% of US1 and 33.3% of US2 patients. MRI analysis showed cerebellar abnormalities in 50% of US1 and 75% of US2 patients, but no clear correlation was observed between structural abnormalities and clinical findings. A pattern for the MRI classification of US patients is suggested.

Abnormalities, Multiple↗
PubMed1996

Results of Expedicion Humana. I. Analysis of HLA class II (DRB1-DQA1-DPB1) alleles and DR-DQ haplotypes in nine Amerindian populations from Colombia.

HLA class II variation was analyzed in nine Native American populations of Colombia using PCR/SSOP typing methods. Under the auspices of the Expedition Humana, approximately 30 unrelated native Colombia Indian samples each from the Tule (NW Pacific Coast), Kogui (Sierra Nevada). Ijka (Sierra Nevada), Ingano (Amazonas), Coreguaje (Amazonas), Nukak (Amazonas), Waunana (Pacific), Embera (Pacific) and Sikuani (Northeastern Plains) were collected and analyzed at the DRBI, DQA1, DQB1 and DPB1 loci. The number of different DRB1, DQA1, DQB1 and DPB1 alleles in the Colombian Indians is markedly reduced in comparison with neighboring African Colombian populations, which exhibit a very high degree of class II variability, as discussed in an accompanying paper. In the Colombian Amerindian groups, DR2 (DRB1*1602), DR4 (DRB1*0407, *0404, *0403 AND *0411), DR6 (DRB1*1402) and DR8 (DRB1*0802) comprise > 95% of all DRB1 alleles. We also found an absence of DR3 in all populations, and DR1, DR7 and DR9 allelic groups were either very rare or absent. Each Colombian Amerindian population has a predominant DRB1 allele (f = approximately 0.22-0.65) and DRB1-DQA1-DQB1 haplotype. Several novel DR-DQ haplotypes were also found. At the DPB1 locus, DPB1*0402 (f = 0.28-0.82), *1401 (f = 0.03-0.45), and *3501 (f = 0.03-0.27), were the three most prevalent alleles, each population maintaining one of these three alleles as the predominant (f > 0.26) DPB1 allele. The reduction of diversity for the HLA class II alleles in the Colombian Indians is suggestive of a population bottleneck during the colonization of the Americans, with little to no subsequent admixture with neighboring African Colombian populations in the last approximately 300 years.

Colombia↗
PubMed1996

HLA-DPB1 polymorphism in seven South American Indian tribes in Colombia.

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.

Alleles↗
PubMed1996

HLA antigens in Ameridian groups of two different linguistic families from Colombia.

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.

Colombia↗
PubMed1993

Human retroviruses in Amerindians of Colombia: high prevalence of human T cell lymphotropic virus type II infection among the Tunebo Indians.

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.

Adolescent↗
PubMed1992

Study of the etiology of deafness in an institutionalized population in Colombia.

To identify causative factors we screened 1,715 deaf individuals from 16 schools for the deaf in Colombia. We found evidence of environmental causation in 579 (33.8%) cases, genetic in 608 (35.4%), and in 528 (30.8%) we were unable to identify the etiology. The degree of hearing loss was severe to profound in 1,238 (72.2%), although in 987 (57.5%) of the deaf population studied the hearing impairment was not noticed until 2 to 5 years of age. The frequent association of deafness with other anomalies underscores the importance of a careful clinical and ophthalmologic evaluation in individuals with hearing loss. Our observations also emphasize the need for programs directed towards the prevention of hearing loss, including primary prevention as well as early diagnosis, investigation of possible genetic causes, and rehabilitation of deaf individuals.

Adolescent↗
PubMed1992

Coexistence of human T-lymphotropic virus types I and II among the Wayuu Indians from the Guajira Region of Colombia.

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.

Blotting, Western↗
PubMed1991

Usher syndrome: results of a screening program in Colombia.

Otological, ophthalmological and genetic studies were performed in 46 patients with Usher syndrome, identified through a screening program in Colombia. Of them, 69.6% had Usher syndrome type I, 26.1% type II, and 4.3% type III. Thirty-three patients showed profound deafness (71.7%), while 13 (28.3%) had moderate to severe hearing loss. The ophthalmologic manifestations showed marked variability. Although the majority of the patients had serious ocular impairment before age 20, 32.6% had good central visual acuity. The prevalence of Usher syndrome in Colombia, estimated at 3.2/100,000, warrants the implementation of screening programs in schools for the deaf and for the blind. Our study confirms that Usher syndrome shows no geographic or racial variation and that the disorder has a wide variability of expression and genetic heterogeneity. The large size of the families we have detected may provide important opportunities for further genetic studies, particularly in terms of the assignment of the locus and gene mapping.

Colombia↗
PubMed1990

Actinic prurigo among the Chimila Indians in Colombia: HLA studies.

The Chimila, a Colombian Amerindian group that lives at a low altitude, have a high incidence of actinic prurigo. We present the human lymphocyte antigen (HLA) findings of 43 Chimilas with the disease and of 62 control subjects and show an association of actinic prurigo with the Cw4 antigen.

Adult↗