Allele frequencies for 15 autosomal STR loci and admixture estimates in Puerto Rican Americans.

Allelic frequencies of 15 short tandem repeats (STR) markers (CSF1PO, FGA, THO1, TPOX, VWA, D3S11358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, D19S433 and D2S1338) were determined using the AmpFl STR Identifiler PCR Amplification Kit in Puerto Rican American individuals (N=205) from Massachusetts. The FGA, D18S51 and D2S1338 loci had a high power of discrimination (PD) with values of 0.967, 0.965 and 0.961, respectively. Significant deviations from the Hardy-Weinberg (HW) equilibrium were not detected. An important genetic contribution of Caucasian European (76.4%) was detected in Puerto Rican Americans. However, comparative analysis between Puerto Rican American and other neighboring populations from United States mainly with African and Caucasian Americans, revealed significant differences in the distribution of STR markers. Our results are important for future comparative genetic studies of different American ethnic groups, in particular a cultural group called Hispanic-Americans and should be helpful for forensic and paternity testing.

Genetic relationship of the Guambino, Paez, and Ingano Amerindians of southwest Colombia using major histocompatibility complex class II haplotypes and blood groups.

We analyzed the Amerindian tribes, Guambiano, Ingano, and Paez of the southwest section of Colombia by major histocompatibility complex class II typing and blood group analysis in order to establish their genetic relationship. In addition, genetic admixture with Caucasian and African ancestry were determined based on blood group typing. The Paez showed admixture with Caucasian populations (22.4%), while the Ingano and Guambiano showed some admixture with Black populations (9.2 and 4.6%, respectively). The Ingano had MHC class II haplotypes found mainly in Amerindian and Asian populations with no evidence of class II haplotypes of African origin. MHC class II haplotypes of Amerindian and Asian populations and some haplotypes frequently found in European Caucasians and Asians and haplotypes of European Caucasians were found in Guambiano and Paez tribes. We compared our results with those previously reported for four Amerindian tribes on Northern Colombia. The presence of some MHC class II haplotypes in the Guambiano, Paez, and Ingano tribes and their absence in the Chibcha speaking groups of Northern Colombia suggest that these tribes originated, together with other Amerindians, from a separate migration or by genetic drift from an ancestral population. Therefore they are genetically distant from Chibcha speaking tribes of Colombia.

Association of HLA-DRB1*1602 and DRB1*1001 with Takayasu arteritis in Colombian mestizos as markers of Amerindian ancestry.

We performed HLA Class I and Class II typing in 16 patients (15 women, one man) with a confirmed diagnosis of Takayasu arteritis. We did not find any of the previously described associations with HLA-B52, and/or HLA-DRB1*1301 alleles. However, in our patients, HLA-DRB1*1602 and HLA-DRB1*1001 were significantly increased. The association of Takayasu arteritis with Amerindian and Asian HLA-DRB1 alleles (DRB1*1602 and DRB1*1001) in the Colombian mestizo patients reported here, and with HLA-B*3906 previously reported in Mexicans, suggest the possibility that some HLA and disease associations are markers for ethnicity of a population carrying a disease gene which is present in an admixed population with the disease.

Population data on 6 short tandem repeat loci in a sample of Caucasian-Mestizos from Colombia.

Blood samples from 409-452 unrelated Colombian Caucasian-Mestizo individuals were amplified and typed for six short tandem repeat (STR) markers (HUMF13A01, HUMFES/FPS, HUMVWA, HUMCSF1PO, HUMTPOX, HUMTH01). The allele frequencies, genotype frequencies, heterozygosity, mean paternity exclusion chance, polymorphism information content, discrimination power, assumption of independence within and between loci and Hardy Weinberg equilibrium were determined. The results demonstrate that all markers conform to Hardy-Weinberg equilibrium expectations. In addition, the results demonstrate the assumption of independence within and between the loci analysed. The mean exclusion chance (MEC) was 0.9851 for all six STR loci analysed and the discrimination power (DP) was 0.9999973. Therefore, this Colombian population database can be used in identity testing to estimate the frequency of a multiple PCR-based locus DNA profile in forensic cases as well as in paternity testing.

Population frequency for the short tandem repeat loci D18S849, D3S1744, and D12S1090 in Caucasian-Mestizo and African descent populations of Colombia.

Blood samples from 489 unrelated Caucasian Mestizo and 252 individuals of African descent in Colombia were amplified and typed for three short tandem repeat (STR) markers (D12S1090, D3S1744, and D18S849). All markers conformed to Hardy-Weinberg equilibrium expectations in both populations studied. In addition, heterozygosity, mean exclusion chance, polymorphism information content, discrimination power, and the assumption of independence within and between loci were determined. The mean exclusion chance for all three STR markers is 0.9750 in the Caucasian Mestizo population and 0.9731 in the African Colombian Population. The discrimination power is 0.999925 and 0.999911 in the Caucasian Mestizo and African Colombian respectively.

Rapidly progressive cholestasis: An unusual reaction to amoxicillin/clavulanic acid therapy in a child.

Hepatotoxity associated with amoxicillin/clavulanic acid is usually a self-limited disease with complete recovery. We report a rapidly progressing liver disease with ductopenia and portal fibrosis in a 3-year-old boy treated with Augmentin.

Immunogenetics of atopic asthma: association of DRB1*1101 DQA1*0501 DQB1*0301 haplotype with Dermatophagoides spp.-sensitive asthma in a sample of the Venezuelan population.

BACKGROUND: Genes linked to the major histocompatibility complex (MHC), have been implicated in atopic asthma. Asthma is highly prevalent in the Venezuelan population (estimated at 20%) and genetic markers are needed to identify populations at risk and plan intervention strategies. OBJECTIVE: To study the influence of the MHC class I and class II genes in the susceptibility to atopic asthma. METHODS: MHC-class I HLA-A, -C, -B and MHC-class II HLA-DR, -DQ, -DP gene haplotype frequencies were determined in 135 Venezuelan mestizos, 71 belong to 20 atopic asthmatic families and 64 unrelated controls. The index cases were 20 atopic asthmatics with positive skin-prick tests and specific serum immunoglobulin E (IgE) for Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f). To ascertain the genes associated with susceptibility to atopy and/or asthma, two control groups were studied, 41 non-atopic subjects with skin-prick negative test, and undetectable levels of specific IgE and 23 non-asthmatic atopic subjects with detectable specific IgE to Der p and Der f. A linkage analysis was performed in those families with two or more atopic siblings (with or without asthma). RESULTS: MHC-class I genes analysis showed that HLA-Cw7 was absent in the asthmatic patients studied, whereas the frequency of this allele was 14.3% in non-atopic controls (P = 0.0 17, PC = 0.19) and 20.8% in the atopic controls (P = 0.0066, PC = 0.07). MHC-class II gene analysis showed a significant increase of the HLA-DRB1*11 in the asthmatic patients compared with non-atopic controls (allele frequencies of 25.6 vs 4.4% P = 0.0017, PC = 0.02). There were no significant differences among asthmatic and atopic controls in the frequency of HLA-DRB1*11 (25.6 vs 17.4%). In contrast, the HLA-DRB1*1101+ haplotypes were significantly higher in asthmatics compared with atopic and non-atopic controls (19.6% vs 2.2% vs 2.3%, PC<0.05). The HLA-DRB1*1101, DQA1*0501, DQB1*0301 haplotype was found significantly increased in the patients vs non-atopic controls (15.4 vs 1.1%, PC< 0.01). The serum levels of specific IgE were detectable in both atopic asthmatics and atopic controls; however, it was higher in atopic asthmatics vs atopic controls Der p (median, 58.7 vs 2.7 kU/L, P<0.001) and Der f (median, 46.9 vs 2.7 kU/L, P<0.001). No linkage between MHC genes and mite-atopy could be documented on informative families with two or more atopic siblings. CONCLUSIONS: We have identified an association between the haplotype HLA-DRB1*1101, DQA1*0501, DQB1*0301 and atopic asthma that confers susceptibility to develop mite-sensitive asthma to atopics (relative risk, RR 8.2), and to non-atopic controls (RR = 15.8) that carry this haplotype. Conversely, the allele HLA-Cw7 was absent in the asthmatics studied and had higher frequencies in the atopic (RR = 0.05) and non-atopic (RR = 0.08) controls. Thus, it may have a protective role for developing atopic asthma in the population studied.

Wiedemann-Rautenstrauch neonatal progeroid syndrome: report of three new patients.

Wiedemann-Rautenstrauch (WR) syndrome is known as a neonatal progeroid syndrome, with only few published case reports. We describe three additional patients, two of them sibs, showing the clinical features of WR syndrome. Skeletal abnormalities are reported and assays of hormones and lipids are presented in one patient. Disturbance in bone maturation and lipid and hormone metabolism appear to be involved in this neonatal progeroid syndrome.

Excess admixture proportion of extended major histocompatability complex haplotypes of Caucasian origin among rheumatoid arthritis associated haplotypes in African Americans and Afro-Caribbeans.

Several extended major histocompatability complex (MHC) haplotypes are associated with susceptibility to autoimmune disease in Caucasian populations. It is known that African Americans and Afro-Caribbeans are ethnic groups descended from west, central and southern black African populations which are admixed with Caucasians. To examine the possible association of some marker of Caucasian MHC genes and susceptibility to rheumatoid arthritis (RA) in African Americans, we studied extended MHC haplotypes (HLA-B, complement and DR) in a sample of 18 African American and Afro-Caribbean probands with RA, their first degree relatives and in 15 non-RA families. We defined 36 disease-associated RA haplotypes among the probands and 96 normal haplotypes in normal individuals. To obtain the most conservative estimate, we excluded recognized Caucasian, DR4-bearing, extended MHC haplotypes from the analysis. Admixture proportions for non-HLA-DR4 extended MHC haplotypes of known Caucasian origin among RA-associated and normal haplotypes were computed (0.40 versus 0.163 respectively). When we compared the difference in proportions between RA and normal haplotypes, the proportion of extended MHC haplotypes of known Caucasian origin was significantly increased among RA-associated haplotypes (Z = 3.16, p (one sided) < 0.001, p (adjusted) < 0.008). Our results suggest that racial admixture with Caucasian MHC genes may augment RA susceptibility and thus may be one mechanism to explain the higher prevalence of RA in African Americans and Afro-Caribbeans than in black African populations.

Chromosome evolution in retinoblastoma.

An attempt to reconstruct the chromosome evolution in 19 primary retinoblastoma tumors was made, taking into consideration the frequencies of the rearrangements for each case. The rearrangements were classified as early or late according to their frequency. Early chromosome rearrangements were +1q, +6p, -13/del(13q), -16/del(16q), -17/del(17p), and late rearrangements were (in decreasing order) -8, -17/del(17p), -22, +3/+3q, -4, -19, +1q, +7/+7q, -14, +21. Chromosome evolution was reconstructed by the analysis of parsimony using programs of phylogenetic inference, which belong to the computer package PHYLIP. Results of the reconstruction of chromosome evolution suggest that there are two types of retinoblastoma tumors which can be distinguished based on chromosome imbalance, and correlate with the presence or absence of additional copies of the short arm (p) of chromosome 6. Tumors with additional 6p chromosome had marked heterogeneity, with a high frequency of early as well as late chromosome changes. By contrast, tumors with a normal 6p complement had the fewest chromosome changes and, in particular, a lower frequency of late changes.

Major histocompatibility complex class II alleles and haplotypes and blood groups of four Amerindian tribes of northern Colombia.

MHC class II alleles and haplotypes were determined from unrelated individuals and families of the Arhuaco (n = 107), Kogi (n = 42), Arsario (n = 18), and Wayú (n = 88) tribes located in the northern part of Colombia. Class II DRB, DQA1, and DQB1 alleles were determined by PCR-SSO and PCR-RFLP based methods. Four haplotypes, [DRB1*0407, DRB4*0101, DQA1*03, DQB1*0302]; [DRB1*0403, DRB4*0101, DQA1*03, DQB1*0302]; [DRB1*1402/1406, DRB3*0101, DQA1*0501, DQB1*0301]; and [DRB1*0802, DQA1*0401, DQB1*0402], were observed among these four tribes. In addition to these haplotypes, the Wayú Indians showed a frequency of 21.3% for the [DRB1*1602, DRB5*02, DQA1*0501, DQB1*0301] haplotype, 13.1% for the [DRB1*0411, DRB4*0101, DQA1*03, DQB1*0302] haplotype, and 8.1% for the [DRB1*0411, DRB4*0101, DQA1*03, DQB1*0402] haplotype. Red cell antigen typing was used to calculate genetic admixture. The Kogi and Arsario showed no genetic admixture while the Arhuaco tribe showed admixture with genes of African origin and the Wayú showed admixture with Caucasians as well as genes of African origin. These findings were confirmed by the MHC class II allele and haplotype data obtained, as alleles and haplotypes of Caucasian and African origin were detected in the Wayú and Arhuaco and not in the Kogi or Arsario. These studies will be important in disease association and transplantation studies for Amerindian and colombian populations and for correlating genetic traits with the anthropologic and linguistic data available in order to better understand the Amerindian populations.

Obstructing endobronchial fibrous histiocytoma: potential for lung salvage.

In the past 10 years two children, ages 3 1/2 and 7 years, have been seen with central endobronchial fibrous histiocytoma causing complete atelectasis. Each child had a 4- to 6-month history of cough, dyspnea and fever. After antibiotic failure, x-rays demonstrated complete unilateral lung collapse. Bronchoscopy in case 1 demonstrated total occlusion of the left mainstem bronchus with 80% stenosis of the right. Left pneumonectomy was ultimately performed with removal of tumor frm the right bronchus. Ten years later the patient is well. Case 2 had an extrinsic etiology ruled out by computed tomography scan. Ventilation/perfusion scan showed no ventilation and only faint perfusion of the involved lung. Pulmonary function testing showed moderate to severe restrictive changes with air trapping. Total obliteration of the left mainstem with tumor projecting into the carina was observed on bronchoscopy. Endoscopic resection was not felt to be safe. Thoracotomy showed a totally atelectatic, edematous lung filled with pus. The left main bronchus was opened, the tumor removed, and the distal bronchus lavaged and selectively ventilated. Partial lung expansion was obtained. The child is well 1 1/2 years later with a normal chest radiograph, pulmonary function tests, and bronchoscopy. Fibrous histiocytomas of the lung, if in a central endobronchial location, can cause complete lung collapse. A combination of tumor resection, lavage, and selective ventilation should be attempted as an alternative to pneumonectomy, even if the lung appears to be nonsalvageable.

Primary alveolar capillary dysplasia.

We describe two neonates with a lethal form of pulmonary maldevelopment. Both infants had bilateral dysplastic immature lungs with poor capillary formation and lack of alveolar development. This rare entity should be considered in the differential diagnosis of a newborn infant with mild diffuse radiographic pulmonary abnormality and severe respiratory distress.

Failure of tumor necrosis factor to produce hypotensive shock in the absence of endotoxin.

Tumor necrosis factor (TNF) is reported to cause a shock syndrome similar to that produced by endotoxin (LPS). The purpose of this study was to determine the relationship between TNF and LPS in causing shock. Eighty rats received infusions of either TNF, LPS, or TNF plus LPS, as compared with saline solution. Temperature, blood, and tissue specimens were obtained at 2 hours. Blood pressure was measured over 4 hours in a separate group of awake rats. Mortality was assessed over 24 hours. Neither TNF (1 mg/kg) nor LPS (1 mg/kg) altered hematocrit, blood gases, temperature, or caused hypotension or mortality. If the same dose of TNF was combined with LPS, however, there was significant (p less than 0.05) hemoconcentration and metabolic acidosis associated with hypotension and 100% mortality by 4 hours. Pathologic changes were restricted to the small intestine and occurred in this group only. It was concluded that TNF does not cause hypotension or shock in the rat. TNF will cause lethal shock, however, if combined with a sublethal dose of endotoxin. This suggests that synergy between TNF and endotoxin is important in septic shock.