RESUMO
INTRODUCTION: Esophageal replacement is a surgical alternative once native esophagus can't be preserved. Different organs and routes for the replacement have been described, being the retroesternal route the least used. The aim is to present our results using gastric tube esophagoplasty with a retroesternal approach. PATIENTS AND METHODS: We performed a retrospective and descriptive study of 11 patients operated from 2000 to 2015. Median age at surgery was 2.2 years (5 months-9 years) and median weight was 11.2 kg (7.8-21). A gastric tube esophagoplasty using the retroesternal route, forced pyloric dilatation and end-to-side esophago-gastric cervical anastomosis were performed. RESULTS: Ten esophagus replacements had long-gap esophageal atresia and one, severe esophagus caustication secondary to button battery ingestion. No intraoperatory complications were observed. Three patients developed anastomosis leak. Two cases developed anastomotic stenosis managed with endoscopic dilatation in 2 and 4 occasions, respectively. Four patients showed occasional dumping syndrome and are asymptomatic after medical treatment. With a median follow up of 6.3 years (0.2-14.8), all our patients are alive and complete oral diet has been established in all of them. CONCLUSIONS: Gastric tube esophagoplasty using the retroesternal route is a suitable technique in order to reestablish gastrointestinal continuity once native esophagus can't be preserved. In our experience is a safe option, related to few complications.
INTRODUCCION: La sustitución esofágica es una de las opciones quirúrgicas en pacientes en los que no es posible la preservación del esófago. Existen diferentes técnicas según el órgano ascendido y la vía de ascenso, siendo la vía retroesternal la menos empleada. Se describen los resultados con el uso de estómago tubulizado retroesternal. PACIENTES Y METODOS: Estudio descriptivo retrospectivo de una serie de 11 pacientes intervenidos entre los años 2000 y 2015, con una edad media en el momento de la intervención de 2,2 años (5 meses-9 años) y un peso de 11,2 kg (7,8-21 kg). Se realizó gastroplastia tubulizada con dilatación forzada de píloro, ascenso gástrico por vía retroesternal y anastomosis esófago-gástrica cervical término-lateral. RESULTADOS: Diez sustituciones se realizaron en pacientes con atresia de esófago long-gap y una, tras una causticación esofágica por pila de botón. No hubo ninguna complicación intraoperatoria. En tres pacientes hubo fuga anastomótica. En dos pacientes se produjo estenosis que precisó dilataciones en 2 y en 4 ocasiones, respectivamente. Cuatro pacientes presentaron síndrome dumping ocasional que se resolvió con tratamiento médico. Con un seguimiento medio de 6,3 años (0,2-14,8), ningún paciente ha fallecido y en todos se ha logrado la nutrición oral completa. CONCLUSIONES: La gastroplastia tubulizada retroesternal es una técnica eficaz para restablecer la continuidad gastrointestinal en aquellos pacientes en los que no es posible preservar el esófago. Puede ser una opción segura y con escasas complicaciones.
Assuntos
Nutrição Enteral/instrumentação , Esofagoplastia/métodos , Esôfago/cirurgia , Esterno/cirurgia , Estômago/cirurgia , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/instrumentação , Anastomose Cirúrgica/métodos , Fístula Anastomótica/etiologia , Criança , Pré-Escolar , Dilatação , Esofagoplastia/efeitos adversos , Humanos , Lactente , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/terapia , Estudos RetrospectivosRESUMO
Several years ago, we initiated a long-term project of cloning new human ATP-binding cassette (ABC) transporters and linking them to various disease phenotypes. As one of the results of this project, we present two new members of the human ABCC subfamily, ABCC11 and ABCC12. These two new human ABC transporters were fully characterized and mapped to the human chromosome 16q12. With the addition of these two genes, the complete human ABCC subfamily has 12 identified members (ABCC1-12), nine from the multidrug resistance-like subgroup, two from the sulfonylurea receptor subgroup, and the CFTR gene. Phylogenetic analysis determined that ABCC11 and ABCC12 are derived by duplication, and are most closely related to the ABCC5 gene. Genetic variation in some ABCC subfamily members is associated with human inherited diseases, including cystic fibrosis (CFTR/ABCC7), Dubin-Johnson syndrome (ABCC2), pseudoxanthoma elasticum (ABCC6) and familial persistent hyperinsulinemic hypoglycemia of infancy (ABCC8). Since ABCC11 and ABCC12 were mapped to a region harboring gene(s) for paroxysmal kinesigenic choreoathetosis, the two genes represent positional candidates for this disorder.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Cromossomos Humanos Par 16 , Sequência de Aminoácidos , Sequência de Bases , Linhagem Celular , Mapeamento Cromossômico , Clonagem Molecular , Humanos , Dados de Sequência Molecular , Proteína 2 Associada à Farmacorresistência Múltipla , FilogeniaRESUMO
Introducción. La sustitución esofágica es una de las opciones quirúrgicas en pacientes en los que no es posible la preservación del esófago. Existen diferentes técnicas según el órgano ascendido y la vía de ascenso, siendo la vía retroesternal la menos empleada. Se describen los resultados con el uso de estómago tubulizado retroesternal. Pacientes y métodos. Estudio descriptivo retrospectivo de una serie de 11 pacientes intervenidos entre los años 2000 y 2015, con una edad media en el momento de la intervención de 2,2 años (5 meses-9 años) y un peso de 11,2 kg (7,8-21 kg). Se realizó gastroplastia tubulizada con dilatación forzada de píloro, ascenso gástrico por vía retroesternal y anastomosis esófago-gástrica cervical término-lateral. Resultados. Diez sustituciones se realizaron en pacientes con atresia de esófago long-gap y una, tras una causticación esofágica por pila de botón. No hubo ninguna complicación intraoperatoria. En tres pacientes hubo fuga anastomótica. En dos pacientes se produjo estenosis que precisó dilataciones en 2 y en 4 ocasiones, respectivamente. Cuatro pacientes presentaron síndrome dumping ocasional que se resolvió con tratamiento médico. Con un seguimiento medio de 6,3 años (0,2-14,8), ningún paciente ha fallecido y en todos se ha logrado la nutrición oral completa. Conclusiones. La gastroplastia tubulizada retroesternal es una técnica eficaz para restablecer la continuidad gastrointestinal en aquellos pacientes en los que no es posible preservar el esófago. Puede ser una opción segura y con escasas complicaciones
Introduction. Esophageal replacement is a surgical alternative once native esophagus cant be preserved. Different organs and routes for the replacement have been described, being the retroesternal route the least used. The aim is to present our results using gastric tube esophagoplasty with a retroesternal approach. Patients and methods. We performed a retrospective and descriptive study of 11 patients operated from 2000 to 2015. Median age at surgery was 2.2 years (5 months-9 years) and median weight was 11.2 kg (7.8-21). A gastric tube esophagoplasty using the retroesternal route, forced pyloric dilatation and end-to-side esophago-gastric cervical anastomosis were performed. Results. Ten esophagus replacements had long-gap esophageal atresia and one, severe esophagus caustication secondary to button battery ingestion. No intraoperatory complications were observed. Three patients developed anastomosis leak. Two cases developed anastomotic stenosis managed with endoscopic dilatation in 2 and 4 occasions, respectively. Four patients showed occasional dumping syndrome and are asymptomatic after medical treatment. With a median follow up of 6.3 years (0.2-14.8), all our patients are alive and complete oral diet has been established in all of them. Conclusions. Gastric tube esophagoplasty using the retroesternal route is a suitable technique in order to reestablish gastrointestinal continuity once native esophagus cant be preserved. In our experience is a safe option, related to few complications
Assuntos
Humanos , Criança , Esofagoplastia/métodos , Gastroplastia/métodos , Atresia Esofágica/cirurgia , Estudos Retrospectivos , Intubação IntratraquealRESUMO
INTRODUCCIÓN: La onicocriptosis o uña incarnata es una patología altamente prevalente en la población pediátrica. El abordaje quirúrgico es el tratamiento definitivo en estadios avanzados, siendo la onicectomía con matricectomía química y la mecánica las técnicas más utilizadas. El objetivo de este estudio es comparar la tasa de recidivas locales de ambas técnicas quirúrgicas. Población y métodos: Se realiza un estudio ambispectivo entre 2010 y 2017 en pacientes con diagnóstico de onicocriptosis que fueron intervenidos quirúrgicamente. Grupo A: onicectomía parcial con matricectomía química con fenol. Grupo B: matricectomía por abrasión mecánica. Se recogen variables demográficas, quirúrgicas, postoperatorias inmediatas y complicaciones a largo plazo. El análisis estadístico se realizó con el programa estadístico SPSS Statics versión 22, considerándose significación estadística un valor de p <0,05. RESULTADOS: Un total de 87 pacientes se incluyeron en el estudio. En el grupo A (12 pacientes), 2 casos (16,7%) presentaron celulitis locales postoperatorias, 4 casos (33%) presentaron recidivas ipsilaterales y uno de ellos, una segunda recidiva. En el grupo B (75 pacientes) no se describen complicaciones postoperatorias inmediatas y 7 pacientes (9%) padecieron recidivas ipsilaterales, de los cuales 3 tuvieron una segunda recidiva. Ambos grupos presentaron diferencias estadísticamente significativas en el índice de recidivas (p= 0,04). CONCLUSIÓN: En nuestra experiencia la onicectomía parcial con matricectomía mecánica por abrasión presenta una baja tasa de complicaciones y de recidivas locales respecto a la fenolización en población pediátrica. Es necesaria la realización de nuevos estudios prospectivos aleatorizados para confirmar esta diferencia
INTRODUCTION: The onychocryptosis in the pediatric population is a highly prevalent pathology. The surgical approach is the treatment of choice in advanced stages with two different techniques, onicectomy with matricectomy by chemical or mechanical abrasion. The purpose of this study is to compare the local recurrences in these two different approaches. MATERIAL AND METHODS: This is an ambispective cohort study between 2010 and 2017 in two groups. Group A: partial onicectomy with matricectomy by chemical abrasion with phenol. Group B: matricectomy by mechanical abrasion. Demographic, surgical, immediate postoperative variables and long-term complications are compared. The statics was performed with the SPSS Static 22 software. P value < 0.05 is consider statistically significant. RESULTS: The study included 87 patients. In group A (12 patients), or chemical matricectomy two cases (16.7%) presented local cellulitis, 4 cases (33%) presented a local recurrence and one of them suffered from a second recurrence. Group B (75 patients) or mechanical matricectomy, did not show immediate postoperative complications and 7 patients (9%) suffered from an ipsilateral recurrence. A second recurrence appeared in three of them. The differences in the recurrence rate between group A and B were statistically significant (p = 0.04). CONCLUSION: In our experience partial onicectomy with matricectomy by mechanical abrasion in onychocryptosis has a low rate of complications and local recurrences compared to phenolization in pediatric patients. It is necessary to perform new randomized and prospective studies to confirm this difference
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Unhas Encravadas/cirurgia , Procedimentos Cirúrgicos Menores/métodos , Fenóis/uso terapêutico , Terapia Combinada/métodosRESUMO
We have taken advantage of the presence of retrotransposed L1 elements within the centromeric alphoid sequences of the human genome to characterize polymorphic markers at the centromeres of human chromosomes 17 and 11 (D17S2205 and D11S4975, respectively). They correspond to microsatellites found at the 3' ends of L1 elements inserted within the alpha satellite sequences of the two chromosomes. They were detected after PCR by direct analysis in sequencing gels. Eight and five alleles, respectively, were found with heterozygosities of 0.67 and 0.68. They were converted into STSs by designing primers specific for each. D17S2205 and D11S4975 can be used as genuine anchor-informative genetic points for chromosomes 17 and 11. Both markers have been placed on the available genetic maps of their centromeric regions. The alphoid domain within which D17S2205 is embedded is ancestral to the canonical ones on chromosome 17 that exhibit several haplotypes in present-day human populations.
Assuntos
Centrômero/genética , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 17/genética , Repetições de Microssatélites , DNA Satélite/análise , DNA Satélite/química , DNA Satélite/genética , Eletroforese em Gel de Campo Pulsado , Humanos , Dados de Sequência Molecular , Linhagem , Polimorfismo GenéticoRESUMO
A number of the Alu and L1 elements present within the centromeric regions of the human chromosomes have been analyzed by polymerase chain reaction amplification. The oligonucleotide primers were homologous to the 3' end consensus sequences of either Alu or L1 in conjunction with an oligonucleotide primer homologous to alphoid sequences specific to different chromosomes. This allowed one to detect an unusual number of Alu and L1 polymorphisms at different loci. It is proposed that this results from molecular rearrangements which occur within the alpha-satellite DNA in which they are embedded (Marçais et al. J. Mol. Evol. 33:42-48, 1991) and not because the centromeric regions are targets for new insertions of such elements. The same analyses were made on cosmids and YACs originating from the centromeric region of chromosome 21 as well as on a collection of somatic hybrids containing chromosome 21 centromere as unique common human genetic material. The results were consistent with the above hypothesis.
Assuntos
Centrômero/genética , Elementos de DNA Transponíveis/genética , Proteínas de Ligação a DNA/genética , Sequências Repetitivas de Ácido Nucleico/genética , Mapeamento Cromossômico , Cromossomos Humanos/genética , Marcadores Genéticos , HumanosRESUMO
Cultured vascular smooth muscle cells express distinct histological phenotypes due to a contractile to synthetic stage transition. In this study, we compared the behaviour of cultured aortic smooth muscle cells from young normal and mdx mice. Morphological, immunobiochemical, immunocytochemical analyses and contraction studies of these cells demonstrated that (i) the cell cytoskeleton in mdx mice is not affected by the absence of dystrophin since proteins such as caldesmon, a-actin, and vinculin are expressed similarly in normal mice, (ii) utrophin (or dystrophin-related protein) overexpression does not compensate for the physiological and functional role of the lacking dystrophin. These data suggested that dystrophin and utrophin cannot substitute one another and may play different or complementary roles within smooth muscle cells.
Assuntos
Distrofina/fisiologia , Proteínas de Membrana , Contração Muscular/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/fisiologia , Animais , Células Cultivadas , Proteínas do Citoesqueleto/fisiologia , Citoesqueleto/ultraestrutura , Distrofina/deficiência , Imunofluorescência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Fenótipo , UtrofinaRESUMO
We have detected and characterized a highly polymorphic marker that maps to the centromere of human chromosome 5. The localization was established by both linkage analysis within the CEPH reference families and fluorescence in situ hybridization. The marker consists of a sequence of five nucleotides, (CCTTT)n. Nineteen alleles have been detected in 46 unrelated individuals from 12 CEPH families, with a calculated heterozygosity of 0.91. This is the first truly centromeric, highly polymorphic genetic marker described so far.
Assuntos
Centrômero , Cromossomos Humanos Par 5 , Alelos , Sequência de Bases , Marcadores Genéticos , Humanos , Hibridização in Situ Fluorescente , Dados de Sequência Molecular , Polimorfismo GenéticoRESUMO
In the course of a search for microsatellites as centromeric polymorphic markers at the 3' ends of Alu or L1 elements, we observed a much higher frequency of L1 than Alu elements embedded within alpha satellite DNA. By sequence analysis of the L1 elements at their alphoid locus of insertion, we found that the insertion site was specific, with the consensus being (Py)2-10/ (Pu)3-7. All potential sites within the consensus alphoid 171-bp repeat are occupied by such elements. This confirms the finding by Feng et al. (1996; Human retrotransposon encodes a conserved endonuclease required for retrotransposition, Cell 87:905-916) that the progenitor L1 elements encode a site-specific endonuclease and that they generate copies that are inserted at these specific sites. The analysis of retrotransposed L1 elements within the alphoid domains of the acrocentric chromosomes showed that a number of loci are shared among all five acrocentrics. This sheds light on the manner in which centromeric regions of these chromosomes are exchanging information during evolution.
Assuntos
Cromossomos Humanos/genética , DNA Satélite/genética , Retroelementos/genética , Sequência de Bases , Evolução Molecular , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNARESUMO
The ABCA subfamily of ABC transporters includes ten members to date. In this study, we describe an additional gene, ABCA12. Four full-length cDNA sequences have been obtained from human placenta that contain two different polyadenylation sites and two splicing forms, coding for ABCA12 isoforms of 2,595 and 2,516 amino acid residues. Both isoforms are predicted to have two ATP-binding domains (nucleotide binding domain, NBD) and two transmembrane (TM) domains, features shared by all other ABCA subfamily proteins. ABCA12 is most closely related to ABCA1, with an amino acid similarity of 47%. Northern blot analysis demonstrates that a 9.5-kb transcript is mainly expressed in the stom- ach. ABCA12 was mapped to human chromosome 2q34. Two other genes from ABCA subfamily are associated with human inherited diseases, ABCA1 with the cholesterol transport disorders Tangier disease and familial hypoalphalipoproteinemia, and ABCA4 with several retinal degeneration disorders. The ABCA12 gene is located in a region of chromosome 2q34 that harbors the genes for lamellar ichthyosis, polymorphic congenital cataract, and insulin-dependent diabetes mellitus (IDDM13), and therefore is a positional candidate for these pathologies.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Cromossomos Humanos Par 2 , Transportadores de Cassetes de Ligação de ATP/biossíntese , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/classificação , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Cromossomos Humanos Par 2/química , Clonagem Molecular , DNA Complementar/isolamento & purificação , Humanos , Dados de Sequência Molecular , Filogenia , Sítios de Splice de RNA , RNA Mensageiro/biossíntese , Homologia de Sequência de Aminoácidos , Distribuição TecidualRESUMO
Human centromeres are poorly understood at both the genetic and the physical level. In this paper, we have been able to distinguish the alphoid centromeric sequences of chromosome 5 from those of chromosome 19. This result was obtained by pulsed-field gel electrophoresis after cutting genomic DNA with restriction endonucleases NcoI (chromosome 5) and BamHI (chromosome 19). We could thus define a highly polymorphic marker, representing length variations of the D5Z1 domain located at the q arm boundary of the chromosome 5 centromere. The centromeric region of chromosome 5 was then analyzed in full detail. We established an approximately 4.6-Mb physical map of the whole region with five rare-cutting enzymes by using nonchimeric YACs, two of which were shown to contain the very ends of 5cen on both sides. The p-arm side of 5cen was shown to contain an alphoid subset (D5Z12) different from those described thus far. Two genes and several putative cDNAs could be precisely located close to the centromere. Several L1 elements were shown to be present within alpha satellites at the boundary between alphoid and nonalphoid sequences on both sides of 5cen. They were used to define STSs that could serve as physical anchor points at the junction of 5cen with the p and q arms. Some STSs were placed on a radiation hybrid map. One was polymorphic and could therefore be used as a second centromeric genetic marker at the p arm boundary of 5cen. We could thus estimate recombination rates within and around the centromeric region of chromosome 5. Recombination is highly reduced within 5cen, with zero recombinants in 58 meioses being detected between the two markers located at the two extremities of the centromere. In its immediate vicinity, 5cen indeed exerts a direct negative effect on meiotic recombination within the proximal chromosomal DNA. This effect is, however, less important than expected and is polarized, as different rates are observed on both arms if one compares the 0 cM/Mb of the p proximal first 5.5 Mb and the 0.64 cM/Mb of the q proximal first 5 Mb to the sex-average 1.02 cM/Mb found throughout the entire chromosome 5. Rates then become close to the average when one goes further within the arms. Finally, most recombinants (21/22), irrespective of the arm, are of female origin, thus showing that recombination around 5cen is essentially occurring in the female lineage.
Assuntos
Centrômero/genética , Cromossomos Humanos Par 5/genética , Recombinação Genética , Southern Blotting , Cromossomos Artificiais de Levedura , Mapeamento de Sequências Contíguas , Eletroforese em Gel de Campo Pulsado , Humanos , Modelos Genéticos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Sondas de Oligonucleotídeos , Linhagem , Mapeamento Físico do Cromossomo , Mapeamento por Restrição , Análise de Sequência de DNA , Sitios de Sequências Rotuladas , TemperaturaRESUMO
The ABCA subfamily of ATP-binding cassette (ABC) transporters includes eleven members to date. In this study, we describe a new, unusually large gene on chromosome 7p12.3, ABCA13. This gene spans over 450 kb and is split into 62 exons. The predicted ABCA13 protein consists of 5,058 ami- no acid residues making it the largest ABC protein described to date. Like the other ABCA subfamily members, ABCA13 contains a hydrophobic, predicted transmembrane segment at the N-terminus, followed by a large hydrophilic region. In the case of ABCA13, the hydrophilic region is unexpectedly large, more than 3,500 amino acids, encoded by 30 exons, two of which are 4.8 and 1.7 kb in length. These two large exons are adjacent to each other and are conserved in the mouse Abca13 gene. Tissue profiling of the major transcript reveals the highest expression in human trachea, testis, and bone marrow. The expression of the gene was also determined in 60 tumor cell lines and the highest expression was detected in the SR leukemia, SNB-19 CNS tumor and DU-145 prostate tumor cell lines. ABCA13 has high similarity with other ABCA subfamily genes which are associated with human inherited diseases: ABCA1 with the cholesterol transport disorders Tangier disease and familial hypoalphalipoproteinemia, and ABCA4 with several retinal degeneration disorders. The ABCA13 gene maps to chromosome 7p12.3, a region that contains an inherited disorder affecting the pancreas (Shwachman-Diamond syndrome) as well as a locus involved in T-cell tumor invasion and metastasis (INM7), and therefore is a positional candidate for these pathologies.
Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/genética , Cromossomos Humanos Par 7 , Transportadores de Cassetes de Ligação de ATP/biossíntese , Sequência de Aminoácidos , Animais , Mapeamento Cromossômico , Sequência Conservada , DNA Complementar/isolamento & purificação , Éxons , Humanos , Camundongos , Dados de Sequência Molecular , Estrutura Terciária de Proteína , RNA Mensageiro/biossíntese , Homologia de Sequência de Aminoácidos , Distribuição Tecidual , Células Tumorais CultivadasRESUMO
We report here the genomic and transcriptional characterization in mouse and man of a novel transporter of the ABCA subclass, named ABCA7. As it is the case for other ABCA genes, the predicted protein encoded by ABCA7 is a full symmetric transporter, highly conserved across species. The ABCA7 gene maps to human chromosome 19 and to the homologous region at band B4-C1 on mouse chromosome 10. The preferential expression of ABCA7 in the spleen, thymus, and fetal liver is consistent with the finding, in both human and mouse promoter, of sites targeted by lymphomyeloid-specific transcription factors. This suggests that ABCA7 may play a pivotal role in the developmental specification of hematopoietic cell lineages.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Éxons/genética , Íntrons/genética , Regiões Promotoras Genéticas/genética , Transportadores de Cassetes de Ligação de ATP/química , Sequência de Aminoácidos , Animais , Linhagem Celular , Cromossomos Humanos Par 19/genética , Sequência Conservada/genética , DNA Complementar/genética , Humanos , Hibridização in Situ Fluorescente , Fígado/embriologia , Fígado/metabolismo , Camundongos , Dados de Sequência Molecular , Especificidade de Órgãos , RNA Mensageiro/análise , RNA Mensageiro/genética , Mapeamento de Híbridos Radioativos , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Baço/metabolismo , Timo/metabolismoRESUMO
Tangier disease is characterized by low serum high density lipoproteins and a biochemical defect in the cellular efflux of lipids to high density lipoproteins. ABC1, a member of the ATP-binding cassette family, recently has been identified as the defective gene in Tangier disease. We report here the organization of the human ABC1 gene and the identification of a mutation in the ABC1 gene from the original Tangier disease kindred. The organization of the human ABC1 gene is similar to that of the mouse ABC1 gene and other related ABC genes. The ABC1 gene contains 49 exons that range in size from 33 to 249 bp and is over 70 kb in length. Sequence analysis of the ABC1 gene revealed that the proband for Tangier disease was homozygous for a deletion of nucleotides 3283 and 3284 (TC) in exon 22. The deletion results in a frameshift mutation and a premature stop codon starting at nucleotide 3375. The product is predicted to encode a nonfunctional protein of 1,084 aa, which is approximately half the size of the full-length ABC1 protein. The loss of a Mnl1 restriction site, which results from the deletion, was used to establish the genotype of the rest of the kindred. In summary, we report on the genomic organization of the human ABC1 gene and identify a frameshift mutation in the ABC1 gene of the index case of Tangier disease. These results will be useful in the future characterization of the structure and function of the ABC1 gene and the analysis of additional ABC1 mutations in patients with Tangier disease.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Glicoproteínas/genética , Doença de Tangier/genética , Transportador 1 de Cassete de Ligação de ATP , Animais , Sequência de Bases , DNA , Éxons , Feminino , Humanos , Íntrons , Masculino , Camundongos , LinhagemRESUMO
The ABCA1 gene, a member of the ATP-binding cassette A (ABCA1) transporter superfamily, encodes a membrane protein that facilitates the cellular efflux of cholesterol and phospholipids. Mutations in ABCA1 lead to familial high density lipoprotein deficiency and Tangier disease. We report the complete human ABCA1 gene sequence, including 1,453 bp of the promoter, 146,581 bp of introns and exons, and 1 kb of the 3' flanking region. The ABCA1 gene spans 149 kb and comprises 50 exons. Sixty-two repetitive Alu sequences were identified in introns 1-49. The transcription start site is 315 bp upstream of a newly identified initiation methionine codon and encodes an ORF of 6,783 bp. Thus, the ABCA1 protein is comprised of 2,261 aa. Analysis of the 1,453 bp 5' upstream of the transcriptional start site reveals multiple binding sites for transcription factors with roles in lipid metabolism. Comparative analysis of the mouse and human ABCA1 promoter sequences identified specific regulatory elements, which are evolutionarily conserved. The human ABCA1 promoter fragment -200 to -80 bp that contains binding motifs for SP1, SP3, E-box, and AP1 modulates cellular cholesterol and cAMP regulation of ABCA1 gene expression. These combined findings provide insights into ABCA1-mediated regulation of cellular cholesterol metabolism and will facilitate the identification of new pharmacologic agents for the treatment of atherosclerosis in humans.