983 resultados para Autosomal recessive


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Gorlin syndrome is a rare autosomal dominant disorder exhibiting high penetrance and variable expressivity. It is characterized by facial dysmorphism, skeletal anomalies, multiple basal cell carcinomas, odontogenic keratocysts (OKC), palmar and plantar pits, bifid ribs, vertebral anomalies and a variety of other malformations. Various neoplasms', such as medulloblastomas, meningiomas, ovarian and cardiac fibromas are also found in this syndrome. Objective: To describe a twelve-year-old patient with Gorlin-Goltz syndrome, with basal cell carcinomas and promyelocytic leukemia developed after receiving craniospinal radiation for a medulloblastoma. Mild ribs as well as mandibular and maxillar OKC were also diagnosed. Conclusion: The patient with Gorlin-Goltz syndrome should receive close follow-up for early detection of malformations and malignant neoplasias.

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We report on five Brazilian patients from three unrelated families with congenital anomalies of the upper limbs. Ulnar aplasia/hypoplasia was the main reason for examining these patients. Evidence for existence of an ulnar developmental field is based on genetic heterogeneity. Clinical and genetic aspects of the ulnar ray defects are discussed.

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The nihB gene of Aspergillus nidulans was found to confer sensitivity to elevated concentrations of nitrite, compact morphology and absence of conidiation. The nihB locus was allocated to linkage group II and was recessive in heterozygous diploids. When the nihB1 mutant was grown on a mixture of nitrite plus NH4 + its sensitivity to nitrite was unchanged. A possible role for this gene in nitrite transport and/or the maintenance of membrane integrity is discussed. © 1992 Rapid Communications of Oxford Ltd.

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Marfan syndrome (MFS) is an autosomal dominant trait due to mutations in the fibrillin gene (FBN1). The MFS expressivity is variable, and its diagnosis relies completely on clinical criteria. Atypical cases and Marfan- like (marfanoid) clinical presentations are commonly found. The metacarpophalangeal pattern profile (MCPP), a radiological method in which the 19 tubular hand bones are assessed, has been used in the diagnosis of various syndromes. To investigate whether the MCPP was adequate to discriminate between MFS and Marfan-like subjects, we studied 38 patients who were referred to our service because they had an MFS diagnosis, diagnostic hypothesis, or differential diagnosis or had arachnodactyly with dolichostenomelia. Two groups were formed: 1) MFS: 21 patients with a mean age of 18.3 (10.8 S.D.) years and 2) Marfan-like syndromes: 16 patients who did not meet the current criteria, with a mean age of 14.6 (4.6 S.D.) years. The MCPP was performed in each case following the classical technique, and a characteristic mean profile was obtained for group I (MFS), with Z scores ranging from 0.69 to 2.73 (1.80 ± 0.50; mean ± S.D.). In group I, three cases had no correlation with the typical MFS pattern. In group II, three cases had an MFS pattern. The correlation with the mean MCPP of MFS permitted the differential diagnosis of MFS and marfanoid syndromes with 86% sensitivity, 81% specificity, and 86% positive and 81% negative predictive values. The results suggest that MCPP can be used effectively as an auxiliary tool in the nosology of these conditions and, because there is no change in MCPP with age, can be helpful in early diagnosis.

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The karyotypes of 15 species of Termitidae were analyzed. All of them are X1X2Y1Y2 (male) and X1X1X2X2 (female). With the exception of Neocapritermes opacus with 2n=40, the remaining species are 2n=42 in both sexes, a karyotype similar to those described for African species by other authors. The sex determining mechanism probably originated before the split up of Gondwanaland, in a single event, early during the karyotype evolution of the family Termitidae by means of a reciprocal translocation that involved the primitive Y and a chromosome from an autosomal pair.

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A synaptonemal complex (SC) study of specimens of Nellore and Gyr breeds of Bos taurus indicus was performed with the main objective to identify and determinate the frequency of abnormalities of SC and the frequency of cells with abnormalities. All animals analyzed had 29 autosomal bivalents and one sexual bivalent. The Nellore breed had 30.00% of cells with SC abnormalities while the Gyr breed had only 11.11%. Statistical analyses showed that there were not significant differences for the number of cells with abnormalities among the breeds studied. The subspecies Bos taurus indicus had 16.92% of cells showing abnormalities, being 62.82% of these abnormalities in zygotene and 37.18% in pachytene. Some aspects regarding the frequency of cells with abnormalities and the fertility of Nellore and Gyr breeds are discussed.

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The inherited haemoglobinopathies are a heterogeneous group of recessive disorders that include the thalassaemias and sickle cell disease. Nearly a thousand mutant alleles have now been characterized. The mutations are regionally specific and in most cases the geographical and ethnic distribution shave been determined providing the foundation for a program of control through screening, genetic counseling and prenatal diagnosis. The diagnosis of hemoglobinopathies requires care for the methodologies applied and the population group which will be evaluated. The information about the abnormal hemoglobin, the medical and psychological aspects and genetic counseling of the carriers and their families are goals of great importance for the success of preventive programs in this area. Aiming to evaluate the laboratory methods for hemoglobinopathy screening and their use in clinical laboratories, we have compared abnormal hemoglobins incidence in the different population groups: blood donors, anemia carriers, newborn and students. The laboratory methods applied involved eletrophoretic proceedings, cytological and biochemical analysis. Within the period from September 1999 through January 2000, we analyzed 524 individuals with varied types of abnormal hemoglobins. Among blood donors, we diagnosed two sickle cell carriers, which suggest the necessity for better care in the process of selection of blood donor candidates. The current interest in the medical and social aspects of sickle cell anemia has resulted in a great increase in methodology research leading to the development of sickle cell screening techniques.

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Albright hereditary osteodystrophy is a hereditary metabolic disorder of dominant autosomal etiology that is commonly characterized by short stature, round face, small metacarpus and metatarsus, mental retardation, osteoporosis, subcutaneous calcification, variable hypocalcemia, and hyperphosphatemia. In this study, we report a clinical case of a 17-year-old woman with Albright hereditary osteodystrophy, and we discuss her clinical, radiographic, and laboratory test characteristics together with the oral manifestations, and we correlate them with the characteristics found in the literature. We also discuss the odontological management of treatment of related periodontal disease and planning for corrections of related malocclusions.

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We describe affected individuals in three generations of a family and another sporadic case, all Brazilian patients, with a combination of signs that diagnose the BCD syndrome. In addition to the cardinal signs, the sporadic case has hypothyroidism and imperforate anus, which was observed previously in one patient. The broadened phenotype and the possibility of involvement of p63 and IRF6 genes in this condition are discussed. © 2003 Wiley-Liss, Inc.

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The purpose of this work was to study the karyotype, spermatogenesis and nucleolar activity at meiosis, in the species Rhodnius domesticus (Heteroptera, Triatominae). The testicular tubules were cytologically prepared by the conventional method of cell crushing and subsequent application of cytogenetic staining techniques with lacto-acetic orcein and silver-ion impregnation. The species under study presented karyotype 2n= 20A+XY, the modal number of the subfamily Triatominae. The chromosomes presented no primary constriction and were therefore characterized as holocentric. It was observed that the sex chromosomes sometimes were located at the periphery, close to the ring formed by autosomes, at first meiotic division. At metaphases II, sex chromosomes were positioned in the center of the autosomal ring, thus evidencing a postreductional behavior. These same chromosomes showed late migration at anaphases and were clearly impregnated with silver-ions, suggesting they bore Nucleolar Organizer Regions. Dispersed nucleolar corpuscles in cytoplasm until telophase II and small dots in spermatids strongly impregnated with silver, could be seen. Thus, it may be inferred that, in triatomines, the nucleolus does not completely disappear but remains in the form of small corpuscles that have a role in cell differentiation.

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Chromatin organization in the holocentric chromosomes of three triatomines species was cytologically studied by fluorescent in situ hybridization with a 45S rDNA probe of Drosophila melanogaster to localize ribosomal genes. In Triatoma tibiamaculata, metaphases I showed telomeric highlights in a single, larger bivalent. In T. protacta, hybridization was detected in one of the telomeres of an autosomal chromosome. In T. platensis, there were highlights in a single, smaller chromosome (X chromosome). The results obtained did not agree with the expected localization of rDNA genes in the sex chromosomes of triatomines, as demonstrated by silver impregnation, and suggest that the chromosome reorganization that occurred in this group during evolution may be a more important mechanism involved in rDNA distribution.

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Cleidocranial dysplasia (CCD) is a rare syndrome usually caused by an autosomal dominant gene, although 40% of cases of CCD appear spontaneously with no apparent genetic cause. This condition is characterized by several cranial malformations and underdevelopment, absence of the clavicles, and multiple supernumerary and impacted permanent teeth. The diagnosis of this condition is usually based on the presence of the main features (supernumerary teeth, partial or total absence of one or both the clavicles, and bony malformations) and on clinical and familial evidence. The bony and dental features of CCD may be visualized on radiographic images of the face and skull. Here, we present a familial case of CCD and discuss the importance of dental radiographs in diagnosis of the condition.

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Drosophila mulleri (MU) and D. arizonae (AR) are cryptic species of the mulleri complex, mulleri subgroup, repleta group. Earlier cytogenetic studies revealed that these species have different regulatory mechanisms of nucleolar organizing activity. In these species, nucleolar organizing regions are found in both the X chromosome and the microchromosome. In the salivary glands of hybrids between MU females and AR males, there is an interspecific dominance of the regulatory system of the D. arizonae nucleolar organizer involving, in males, amplification and activation of the nucleolar organizer from the microchromosome. The authors who reported these findings obtained hybrids only in that cross-direction. More recently, hybrids in the opposite direction, i.e., between MU males and AR females, have been obtained. The purpose of the present study was to evaluate, in these hybrids, the association of the nucleoli with the chromosomes inherited from parental species in order to cytogenetically confirm the dominance patterns previously described. Our results support the proposed dominance of the AR nucleolar organizer activity over that of MU, regardless of cross-direction. ©FUNPEC-RP.

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This work deals with the comparative cytogenetic analysis of four Neotropical Elateridae species and reviews the nucleolar organizer region (NOR) patterns on Coleoptera chromosomes, for the first time. The cytogenetic characterization of Conoderus malleatus (Conoderini), Pyrearinus candelarius, Pyrophorus divergens and Pyrophorus punctatissimus (Pyrophorini) was accomplished through the study of mitotic and meiotic cells submitted to standard (Giemsa) and differential staining [silver impregnation and GC-specific chromomycin A 3 (CMA 3) plus AT-specific 4′-6-diamidino-2-phenylindole (DAPI) fluorochromes]. The analysis of spermatogonial cells revealed the diploid numbers: 2n = 17 in C. malleatus and 2n = 15 in P. candelarius, P. divergens and P. punctatissimus. In these species, the X0 type sex-determination system and the acrocentric morphology of almost all chromosomes were observed. The study of meiotic cells of the four species revealed the occurrence of total synapsis between the autosomes, the presence of one terminal or interstitial chiasma in the majority of the bivalents, and the reductional behaviour and regular segregation of all chromosomes. Although the three Pyrophorini species demonstrated many similar karyotypical characteristics, there was one discrepancy, which was noted in the diplotene cells and concerns the number of bivalents with two chiasmata; P. candelarius only presented one bivalent, P. divergens showed two bivalents and P. punctatissimus exhibited up to four bivalents with two chiasmata. Testicular cells impregnated with silver nitrate demonstrated two terminal NORs located on the fourth autosomal pair of the Conoderini species and on the second autosomal pair of the three Pyrophorini representatives. Use of CMA 3/distamycin A (DA)/DAPI staining on the P. candelarius and P. punctatissimus chromosomes revealed that the CMA 3 labelled regions were coincident with the NORs. The main strategies of karyotypical differentiation that have occurred among the four Elateridae species and other related species, and the general trends of the NOR shifts during Coleoptera chromosomal evolution are discussed in this work. © 2007 The Authors.

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BACKGROUND AND OBJECTIVES: Myotonic dystrophies are autosomal dominant neuromuscular diseases. Among them, myotonic dystrophy type 1 (MD1), or Steinert disease, is the most common in adults, and besides muscular involvement it also has important systemic manifestations. Myotonic dystrophy type 1 poses a challenge to the anesthesiologist. Those patients are more sensitive to anesthetics and prone to cardiac and pulmonary complications. Besides, the possibility of developing malignant hyperthermia and myotonic episodes is also present. CASE REPORT: This is a 39-year old patient with DM1 who underwent general anesthesia for videolaparoscopic cholecystectomy. Total intravenous anesthesia with propofol, remifentanil, and rocuronium was the technique chosen. Intercurrences were not observed in the 90-minute surgical procedure, but after extubation, the patient developed respiratory failure and myotonia, which made tracheal intubation impossible. A laryngeal mask was used, allowing adequate oxygenation, and mechanical ventilation was maintained until full recovery of the respiratory function. The patient did not develop further complications. CONCLUSIONS: Myotonic dystrophy type 1 presents several particularities to the anesthesiologist. Detailed knowledge of its systemic involvement along with the differentiated action of anesthetic drugs in those patients will provide safer anesthetic-surgical procedure.