Major gene and multifactorial inheritance of mandibular prognathism

Mandibular prognathism typically shows familial aggregation. Various genetic models have been described and it is assumed to be a multifactorial and polygenic trait, with a threshold for expression. Our goal was to examine specific genetic models of the familial transmission of this trait. The study sample comprised of 2,562 individuals from 55 families. Complete family histories for each proband were ascertained and the affection status of relatives were confirmed by lateral cephalograms, photographs, and dental models. Pedigrees were drawn using PELICAN and complex segregation analysis was performed using POINTER. Parts of some pedigrees were excluded to create one founder pedigrees, so the total N was 2,050. Analysis showed more affected females than males (P = 0.030). The majority of the pedigrees suggest autosomal dominant inheritance. Incomplete penetrance was demonstrated by the ratio of affected/unaffected parents and siblings. The heritability of mandibular prognathism was estimated to be 0.316. We conclude that there is a major gene that influences the expression of mandibular prognathism with clear signs of Mendelian inheritance and a multifactorial component. (C) 2007 Wiley-Liss, Inc.

APOE polymorphism is associated with lipid profile, but not with arterial stiffness in the general population

Background: Cardiovascular diseases (CVD) are the main cause of death and disability in developed countries. In most cases, the progress of CVD is influenced by environmental factors and multifactorial inheritance. The purpose of this study was to investigate the association between APOE genotypes, cardiovascular risk factors, and a noninvasive measure of arterial stiffness in the Brazilian population. Methods: A total of 1493 urban Brazilian individuals were randomly selected from the general population of the Vitoria City Metropolitan area. Genetic analysis of the APOE polymorphism was conducted by PCR-RFLP and pulse wave velocity analyzed with a noninvasive automatic device. Results: Age, gender, body mass index, triglycerides, creatinine, uric acid, blood glucose, blood pressure phenotypes were no different between epsilon 2, epsilon 3 and epsilon 4 alleles. The epsilon 4 allele was associated with higher total-cholesterol (p < 0.001), LDL-C (p < 0.001), total-cholesterol/HDL-C ratio (p < 0.001), LDL/HDL-C ratio (p < 0.001), lower HDL-C values (p < 0.001) and higher risk to obesity (OR = 1.358, 95% CI = 1.019-1.811) and hyperuricemia (OR = 1.748, 95% CI = 1.170-2.611). Nevertheless, pulse wave velocity (p = 0.66) measures were no different between genotypes. The significant association between APOE genotypes and lipid levels persisted after a 5-year follow-up interval, but no interaction between time and genotype was observed for lipids longitudinal behavior. Conclusion: The epsilon 4 allele of the APOE gene is associated with a worse lipid profile in the Brazilian urban population. In our relatively young sample, the observed effect of APOE genotype on lipid levels was not translated into significant effects in arterial wall stiffness.

Inheritance of resistance to Puccinia psidii G. Winter in a eucalyptus interspecific hybrid progeny evaluated under conditions of natural infection

Inheritance of resistance to Puccinia psidii G. Winter in a eucalyptus interspecific hybrid progeny evaluated under conditions of natural infection Rust caused by the fungus Puccinia psidii is currently the most important disease of eucalyptus. It is widely disseminated in Brazil, and causes serious damage in nurseries and plantation areas. The identification of resistant germplasm along with knowledge of the genetic basis of resistance heredity are the first requirements for the success of breeding programs aiming to develop resistant varieties. Earlier studies carried out under controlled conditions suggested a monogenic control as well as the participation of at least two genes promoting resistance to rust. The goal of this study was to evaluate the resistance to P. psidii under field conditions in fourteen progenies from controlled crosses and self-crosses among four hybrid clones of Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla ST Blake that contrast for resistance to the fungus. Results indicated that resistance could be explained by one locus with main effects and at least three different alleles. However, loci with minor effects may influence the resistance, since variation on severity classes was observed. Differences in segregation of resistance between reciprocal crosses were not observed, indicating absence of cytoplasmic effects.

Inheritance of growth habit detected by genetic linkage analysis using microsatellites in the common bean (Phaseolus vulgaris L.)

The genetic linkage map for the common bean (Phaseolus vulgaris L.) is a valuable tool for breeding programs. Breeders provide new cultivars that meet the requirements of farmers and consumers, such as seed color, seed size, maturity, and growth habit. A genetic study was conducted to examine the genetics behind certain qualitative traits. Growth habit is usually described as a recessive trait inherited by a single gene, and there is no consensus about the position of the locus. The aim of this study was to develop a new genetic linkage map using genic and genomic microsatellite markers and three morphological traits: growth habit, flower color, and pod tip shape. A mapping population consisting of 380 recombinant F10 lines was generated from IAC-UNA x CAL143. A total of 871 microsatellites were screened for polymorphisms among the parents, and a linkage map was obtained with 198 mapped microsatellites. The total map length was 1865.9 cM, and the average distance between markers was 9.4 cM. Flower color and pod tip shape were mapped and segregated at Mendelian ratios, as expected. The segregation ratio and linkage data analyses indicated that the determinacy growth habit was inherited as two independent and dominant genes, and a genetic model is proposed for this trait.

Mendelian inheritance, linkage and linkage disequilibrium in microsatellite loci of Copaifera langsdorffii Desf.

Copaifera langsdorffii is a Neotropical tree with wide distribution in the Brazilian Atlantic rain forest and savanna. Although eight microsatellite loci (SSR) were developed in 2000 and have been widely used since then, there is yet no information about their inheritance, linkage and linkage disequilibrium (LD). Through the analysis of 28 open-pollinated (OP) progenies, the SSR loci revealed Mendelian inheritance and independent assortment. Using these progenies, young and adult trees LD was mainly detected in OP progenies. Our results show clear evidence that the eight SSR loci can be used without restriction in genetic diversity, mating system and parentage analysis.

Hepatitis Delta virus genotype 8 infection in Northeast Brazil: Inheritance from African slaves?

Hepatitis Delta virus (HDV) is endemic worldwide, but its prevalence varies in different geographical areas. While in the Brazilian Amazon, HDV is known to be endemic and to represent a significant public health problem, few studies have assessed its prevalence in other regions in the country. This study evaluated the seroprevalence of HDV among HBsAg chronic carriers from Maranhao state, a region located in the Northeast of Brazil. Among 133 patients, 5 had anti-HD, of whom 3 had HDV RNA. HDV genotypes were characterized by Bayesian phylogenetic analysis of nucleotide sequences from the HDAg coding region. HDV-3 was identified in one patient who lives in Maranhao, but was born in Amazonas state (Western Amazon basin). Phylogenetic analysis shows that this HDV-3 sequence grouped with other HDV-3 sequences isolated in this state, which suggests that the patient probably contracted HDV infection there. Surprisingly, the other two patients were infected with HDV-8, an African genotype. These patients were born and have always lived in Urbano Santos, a rural county of Maranhao state, moreover they had never been to Africa and denied any contact with people from that continent. This is the first description of the HDV-8 in non-native African populations. This genotype may have been introduced to Brazil through the slaves brought to the country from the West Africa regions during the 16-18th centuries. Our results indicate that the need of clinical and epidemiological studies to investigate the presence of this infection in other areas in Brazil. (C) 2011 Elsevier B.V. All rights reserved.

Oculoauriculovertebral spectrum: report of nine familial cases with evidence of autosomal dominant inheritance and review of the literature

Oculoauriculovertebral spectrum (OAVS; OMIM 164210) is a complex condition characterized by defects of aural, oral, mandibular and vertebral development. The aetiology of this condition is likely to be heterogeneous; most cases are sporadic, however, familial cases suggesting autosomal recessive end autosomal dominant inheritance have been reported. In this study, we describe the clinical aspects of nine familial cases with evidence of autosomal dominant inheritance and compare them with reports in the literature. Interfamilial and intrafamilial clinical variabilities were observed in this study (reinforcing the necessity of careful examination of familial members). We suggest that oculoauriculovertebral spectrum with autosomal dominant inheritance is characterized mainly by bilateral auricular involvement and rarely presents extracranial anomalies. Clin Dysmorphol 18:67-77 (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Color inheritance and pigment characterization of red (wild-type), greenish-brown, and green strains of Gracilaria birdiae (Gracilariales, Rhodophyta)

Species of Gracilaria are some of the most useful algae in the world for the production of agar. As a consequence of its economic importance, the genus has been the subject of many studies worldwide. Color variants of Gracilaria birdiae have been found in the natural population on the Brazilian coast, and they have also been isolated from plants cultivated in laboratory. These findings raised new questions regarding intraspecific variation and the prospects of cultivating such variants for their agar production. Therefore, this work aimed to determine the mode of color inheritance for two G. birdiae strains: a greenish-brown strain (gb) found in a natural population and a green strain (gr) which had arisen as a spontaneous mutation in a red plant cultured in the laboratory. The pigment contents of these strains, as well as the red wildtype (rd), were also characterized. Crosses between female and male plants of the same color (rd, gr, or gb) and between different colors were performed. Crosses between plants of the same color showed tetrasporophytic and gametophytic descendents of the parental color. Recessive nuclear inheritance was found in the greenish-brown strain, and cytoplasmic maternal inheritance was found in the green strain; both had lower phycoerythrin and higher concentrations of allophycocyanin and phycocyanin than the wild-type. Chlorophyll a contents were similar among all strains. Taken together, our results contribute to knowledge about the variability of this important red algae. In addition, since greenish-brown and green strains showed stability of color, both could be selected and tested in experimental sea cultivation to evaluate if mutants have advantageous performance when compared with red strain.

Assessment in vitro of brushing on dental surface roughness alteration by laser interferometry

Noncarious cervical lesions (NCCLs) are considered to be of multifactorial origin, normally associated with inadequate brushing. This study assessed the influence in vitro of simulated brushing on NCCL formation. Fifteen human premolars were submitted to brushing in the cementoenamel junction region, using hard-, medium- and soft-bristled brushes associated with a toothpaste of medium abrasiveness under a 200 g load, at a speed of 356 rpm for 100 minutes. The surface topography of the region was analyzed before and after brushing, by means of a laser interferometer, using "cut-off" values of 0.25 and considering roughness values in mm. The initial roughness (mm) results for dentin (D / bristle consistency: 1 - soft, 2 - medium and 3 - hard) were as follows: (D1) 1.25 ± 0.45; (D2) 1.12 ± 0.44; (D3) 1.05 ± 0.41. For enamel (E / bristle consistency: 1 - soft, 2 - medium and 3 - hard), the initial results were: (E1) 1.18 ± 0.35; (E2) 1.32 ± 0.25; (E3) 1.50 ± 0.38. After brushing, the following were the values for dentin: (D1) 2.32 ± 1.99; (D2) 3.30 ± 0.96; (D3) Over 500. For enamel, the values after brushing were: (E1) 1.37 ± 0.31; (E2) 2.15 ± 0.90; (E3) 1.22 ± 0.47. Based on the results of the ANOVA and Tukey statistical analyses (a = .05) it was concluded that soft, medium and hard brushes are not capable of abrading enamel, whereas dentin showed changes in surface roughness by the action of medium- and hard-bristled brushes.

Control of erosive tooth wear: possibilities and rationale

Dental erosion is a type of wear caused by non bacterial acids or chelation. There is evidence of a significant increase in the prevalence of dental wear in the deciduous and permanent teeth as a consequence of the frequent intake of acidic foods and drinks, or due to gastric acid which may reach the oral cavity following reflux or vomiting episodes. The presence of acids is a prerequisite for dental erosion, but the erosive wear is complex and depends on the interaction of biological, chemical and behavioral factors. Even though erosion may be defined or described as an isolated process, in clinical situations other wear phenomena are expected to occur concomitantly, such as abrasive wear (which occurs, e.g, due to tooth brushing or mastication). In order to control dental loss due to erosive wear it is crucial to take into account its multifactorial nature, which predisposes some individuals to the condition.

Apert syndrome: clinical and radiographic features and case report

PURPOSE: Apert syndrome is a rare type I acrocephalosyndactyly syndrome characterized by craniosynostosis, severe syndactyly of the hands and feet, and dysmorphic facial features. Presents autosomal dominant inheritance assigned to mutations in the fibroblast growth factor receptors gene. The oral cavity of Apert patients includes a reduction in the size of the maxilla, tooth crowding, anterior open-bite of the maxilla, impacted teeth, delayed eruption, ectopic eruption, supernumerary teeth, and thick gingiva. The mandible usually is within normal size and shape, and simulates a pseudoprognathism. CASE DESCRIPTION: A female patient, 13 years old, with diagnosis of Apert syndrome, attended a dental radiology clinic. The clinical signs were occular anomalies, dysmorphic facial features, syndactyly and oral features observed clinically and radiographically. The patient was referred to a specialized center of clinical care for patients with special needs. CONCLUSION: Because of the multiple alterations in patients with Apert syndrome, a multidisciplinary approach, including dentists and neurosurgeons, plastic surgeons, ophthalmologists and geneticists, is essential for a successful planning and treatment.

Alcohol dehydrogenase activities and ethanol tolerance in Anastrepha (Diptera, Tephritidae) fruit-fly species and their hybrids

The ADH (alcohol dehydrogenase) system is one of the earliest known models of molecular evolution, and is still the most studied in Drosophila. Herein, we studied this model in the genus Anastrepha (Diptera, Tephritidae). Due to the remarkable advantages it presents, it is possible to cross species with different Adh genotypes and with different phenotype traits related to ethanol tolerance. The two species studied here each have a different number of Adh gene copies, whereby crosses generate polymorphisms in gene number and in composition of the genetic background. We measured certain traits related to ethanol metabolism and tolerance. ADH specific enzyme activity presented gene by environment interactions, and the larval protein content showed an additive pattern of inheritance, whilst ADH enzyme activity per larva presented a complex behavior that may be explained by epistatic effects. Regression models suggest that there are heritable factors acting on ethanol tolerance, which may be related to enzymatic activity of the ADHs and to larval mass, although a pronounced environmental effect on ethanol tolerance was also observed. By using these data, we speculated on the mechanisms of ethanol tolerance and its inheritance as well as of associated traits.

Estudo de família brasileira portadora de deficiência auditiva sensorioneural não-sindrômica com herança mitocondrial

O presente estudo teve como objetivo descrever os achados audiológicos e genéticos de nove membros de uma família brasileira que apresenta a mutação no DNA mitocondrial. Todos os nove membros realizaram estudo genético, avaliação foniátrica e audiológica (audiometria tonal e logoaudiometria). O estudo genético revelou a presença de mutação mitocondrial A1555G no gene 12S rRNA (MT-RNR-1) do DNA mitocondrial em todos os sujeitos. Oito sujeitos apresentaram deficiência auditiva e somente um apresentou limiares auditivos normais até o término da realização do estudo. Os resultados audiológicos apontaram para perdas auditivas bilaterais, com prevalência das simétricas, de configurações e graus variados (de moderado a profundo) e pós-linguais. Progressão da perda auditiva foi observada em dois irmãos afetados. Não foi possível afirmar a época do início da perda auditiva por falta de informação dos sujeitos, no entanto, observou-se manifestação da perda em crianças e adultos. As mutações no DNA mitocondrial representam uma causa importante de perda auditiva, sendo imprescindível a realização do diagnóstico etiopatológico, a fim de retardar o início ou evitar a progressão da surdez.

A novel missense mutation p.L76P in the GJB2 gene causing nonsyndromic recessive deafness in a Brazilian family

Mutations in the GJB2 gene, encoding connexin 26 (Cx26), are a major cause of nonsyndromic recessive hearing loss in many countries. We report here on a novel point mutation in GJB2, p.L76P (c.227C>T), in compound heterozygosity with a c.35delG mutation, in two Brazilian sibs, one presenting mild and the other profound nonsyndromic neurosensorial hearing impairment. Their father, who carried a wild-type allele and a p.L76P mutation, had normal hearing. The mutation leads to the substitution of leucine (L) by proline (P) at residue 76, an evolutionarily conserved position in Cx26 as well as in other connexins. This mutation is predicted to affect the first extracellular domain (EC1) or the second transmembrane domain (TM2). EC1 is important for connexon-connexon interaction and for the control of channel voltage gating. The segregation of the c.227C>T (p.L76P) mutation together with c.35delG in this family indicates a recessive mode of inheritance. The association between the p.L76P mutation and hearing impairment is further supported by its absence in a normal hearing control group of 100 individuals, 50 European-Brazilians and 50 African-Brazilians.

Dating minerals by ID-TIMS geochronology at times of in situ analysis: selected case studies from the CPGeo-IGc-USP laboratory

Since 1964, the Center for Geochronological Research - CPGeo, one of the interdepartmental centers of the Instituto de Geociências (IG) of São Paulo University, has developed studies related to several geological processes associated with different rock types. Thermal Ionization Mass Spectrometry Isotopic Dilution (ID-TIMS) has been the technique widely used in the CPGeo U-Pb Laboratory. It provides reliable and accurate results in age determination of superposed events. However, the open-system behavior such as Pb-loss, the inheritance problem and metamictization processes allow and impel us to a much richer understanding of the power and limitations of U-Pb geochronology and thermochronology. In this article, we present the current methodology used at the CPGeo-IGc-USP U-Pb laboratory, the improvements on ID-TIMS method, and report high-precision U-Pb data from zircon, monazite, epidote, titanite, baddeleyite and rutile from different rock types of several domains of the Brazilian south-southeast area, Argentina and Uruguay.