American Journal of Genetics

  • Patulin Induced Dominant Lethal Gene in Mature Male and/or Female Rats

    Many fungi including Penicillium and Aspergillus species produces patulin in the contaminated foods. Patulin is a heterocyclic unsaturated lactone that reacts with SH group of biological molecules causing harmful effects in human and animal tissues. Hence, the present investigation was designed to evaluate the possible teratogenic effect of patulin (0.002mg/kg b. wt) which was examined through the induction of dominant lethal gene and the alteration in number of live births in the female rats . Results and Conclusion: patulin is a dangerous teratogen in rats. This was confirmed by the significant increase in the percentage of maternal and embryo toxicities.

  • Selection of Reference Genes in Vitis Vinifera Inoculated With Xanthomonas Campestris

    Introduction: The selection of reference genes (RGs) is considered as one of the most critical steps for RT-qPCR since these genes must show stable expression under varying experimental conditions, cell types, and developmental stages, among other factors. Despite the fact that there are publications for this topic in the grapevine, the majority of them are based on cultivars infected by fungi or subject to abiotic stress. To our knowledge, there is no study investigating the selection of RGs in vine affected by X. campestris. Objective: To select for suitable RGs for gene expression normalization of RNA-Seq expression data from two V. vinifera cultivars with contrasting phenotypes for resistance to this pathogen. Methodology: A search in the literature for publications that selected explicitly for RGs in grapevine was performed, further including those articles using conditions of biotic (preferentially) or abiotic stress. After an initial prospection, the retrieved primers sequences were evaluated by an in silico PCR assay using the Primer-BLAST software at NCBI aiming to align the sequences in the V. vinifera genome and its specific amplification, thus confirming, therefore, gene annotation. Finally, the RGs were tested by both conventional PCR and RT-qPCR and using a negative control (NTC) reaction each tested primer pair. Results and Discussion: From 14 RGs selected, nine (CYP, VATP16, EF1α, TRU5, TCPB, TIF-GTP, GAPDH, ACT, and 60SRP) met the criteria all the criteria described above and its sequences were sent for primer synthesis. The detection by both conventional PCR and RT-qPCR confirmed the amplification of all tested RGs. However, under the RT-qPCR, it was possible to not unspecific amplification on NTC of two RGs (CYP and VATP16), therefore confirming the resolution of the assay. Conclusion: A selection of putative candidate RGs was carried out by showing satisfactory results on initial tests on both convencional PCR and…

  • Main Differences Between Diabetes Mellitus Types 1 and 2 in Relation to Genetic Factors

    Introduction:Diabetes mellitus type 1 (DM1) and 2 (DM2), are responsible for more than 95% of the world cases. Being autoimmune DM1, characterized by the destruction of the pancreatic beta cells through the lymphocytes of the body, multifactorial and dependent on immunological, genetic and environmental factors. On the other hand, DM2 is caused by the inability of pancreatic beta cells to raise the level of insulin in the blood, presenting environmental and genetic factors. Objective: To differentiate genetically the types 1 and 2 diabetes mellitus. Methodology: A literature review was carried out through the Scielo platform, which selected complete articles published between 2007 and 2012 in Portuguese and in the book Williams Treated of endocrinology, 11th edition. Results and Discussion: For DM1 some polymorphic risk genes are known. These are found in the Histocompatibility Complex, more precisely in the region of the Human Leukocyte Antigen (HLA) system on chromosome 6 (p21.3), which are HLA-DQ alpha, HLA-DQ Beta, HLA-DR, insulin and the PTPN22 gene. The HLA-DQ / DR loci are considered the main genetic markers in the presence of antigens in the islets of Langerhans and in the control of the immune response. Non-HLA genes also contribute to the onset of DM1, such as the polymorphism of the insulin gene on chromosome 11, and the genes for the Carrier Involved in the Presentation of Antigen (TAP). In the more rare monogenic form of DM2, mutations occur in the insulin receptor, peroxisome proliferator-activated gamma receptor (PPAR gamma), insulin and a polymorphism in the mRNA mRNA gene. In the most common polygenic forms of DM2, the most studied genes are calpain-10, PPAR gamma2 and Kir6.2. Conclusion: DM1 is complex, and is involved in gene mutations that regulate the immune system. In DM2, mutations occur in membrane proteins. There must be rapid diagnosis so that…

  • Validation of the Conventional PCR technique for diagnosis of AML with NPM1 gene mutation

    Introduction: NPM1 gene mutations are the most frequent mutations in adults with acute myeloid leukemia (AML) they are found in 30% of adult de novo AML and in 60% of AML with normal karyotype. Because its clinical relevancy the European Leukemianet group recommends the research of NPM1 mutations at diagnosis to better stratify the risk of patients with AML. The current methodologies used to detect these mutations – Sanger sequence and fragment analysis- are expensive, therefore, there is the necessity of the development of new and cheapest methodologies for implementation in a routine diagnosis for patients with AML, mainly thinking of development countries. Objectives: To validate the technique of PCR followed by electrophoresis on agarose gel to detect mutations in NPM1 gene in patients with AML. Methodology: 196 patients with de novo AML were analyzed. Conventional PCR was made and the products of its amplification were seen by electrophoresis on agarose gel with 4%. The gold standard used for comparisons was the fragment analysis by the MEGABACE 1000 equipment (GE Healthcare- Amersham). Results and Discussion: 19,4% of the patients were mutated (38 of 196 patients) and 80,6% were normal (158 of 196 patients). All mutations were insertions of 4 base pair. The conventional PCR technique revealed a sensibility and specificity of 100% showing to be a sensitive, simple and economic method which can be used as an alternative to others more expansive methodologies that also need a more specialized professional to the diagnostic routine of patients with AML. Conclusions: This study proposes a faster, economic and sensitive technique to detect mutations on NPM1 gene in a routine diagnostic of patients with AML.

  • Genetic Analysis of the Clinical Manifestations of Lipofuscinosis (Batten Syndrome)

    Introduction: Neuronal Ceroid Lipofuscinosis (NCL) is a group of neurodegenerative genetic diseases characterized by the accumulation of lipid pigment in neuronal lysosomes and other tissues. Batten syndrome (BS) is the juvenile form of this group, beginning in childhood, with its primary symptomatology manifested between 5-10 years of age, with progressive visual loss and decreased intellectual capacity. Objectives: To correlate genotype and phenotype of Batten Syndrome. Methodology: Articles published between 2000 and 2010 were pre-selected through the PubMed and SciELO databases, using the descriptor: neuronal ceroid lipofuscinoses. Twenty texts were initially analyzed, of which ten were selected after the study of titles and abstracts. Considering inclusion and exclusion criteria, only six were included in the review because they referred to the BS theme in the descriptors and abstracts. Results and Discussion: BS, an inherited autosomal recessive disease, results from the CLN3 gene mutation located on the short arm of chromosome 16p12.1, interfering with the function of the battenin protein. Clinical manifestations begin with dementia, changes in visual acuity, as well as speech disturbances, slow decline in cognitive functions and epilepsy. Motor alterations are more common in the adolescence, however, they may appear at early times and vary in intensity. The neuroradiological exams are used for the diagnosis of BS, such as computed tomography, magnetic resonance imaging (MRI) and MR proton spectroscopy, which may demonstrate cerebral and cerebellar atrophy. It is also possible to perform fundoscopy of the eye to detect abnormal pigmentation of the retina and optic atrophy. Conclusion: Due to the difficult diagnosis of BS, a disease of an evolutionary nature, the clinical picture of the patient and its evolution are taken into account. However, neuroradiological exams may contribute to justify some clinical appearances in patients with BS, and genetic molecular mutation analysis may also be performed to better elucidate…

  • Genetic Analysis of Clinical Manifestations of Friedreich Ataxia

    Introduction:Friedreich’s ataxia (FA), an autosomal neurodegenerative disorder, conditions a destruction of nerve cells during the progression of the disease, affecting cardiac, bone and pancreatic cells. It has as main symptoms walking difficulty, progressing to changes in limb sensitivity, speech problems, atypical ocular movements, heart disease and diabetes. Objective: To carry out a review of the literature on Friedreich’s ataxia and its association with genetic alterations and molecular diagnosis. Methodology: Articles published between 2010 and 2015 were pre-selected through the PubMed and SciELO databases, using the descriptor: ataxia. Analyzing the texts, 50 studies were initially identified. After reviewing the abstracts, considering the inclusion and exclusion criteria, 20 were analyzed, 3 were included in the review because they referred to the FA theme in the descriptors and abstracts. Results and Discussion: FA was identified through the genetic mapping, determinating chromosome 9 as the locus of malformation. This chromosome contains the frataxin gene, which encodes a frataxin protein, relating as mutations and causing abnormal repeats of glutamic acid (GAA). Homozygous for GAA represents 94% of patients with the classic form of the disease. The main clinical symptoms of FA are limb ataxia, cerebellar dysarthria, sensorimotor deficit in the lower limbs and pyramidal signs. Its diagnosis is made based on clinical investigations and confirmed from tests of molecular genetics. Thus, the genetic study associated with clinical investigation allows the prognosis, characterizing: a severity of the condition, its evolution and probability of being related to myocardiopathies. Conclusion: FA, an evolutionary disease, causes complete clinical changes after a few years from the beginning of the symptomatology, making early diagnosis difficult. Direct molecular diagnosis through the determination of GAA replicates becomes standard clinical examination, differential diagnosis and genetic counseling for individuals with cerebellar ataxias.