Our observation of a 4.7-fold (95% CI: 2.1-11.0) and 2.3-fold (95% CI: 1.0-5.2) increased risk associated with the GSTM1 and GSTT1 null genotypes, respectively, and a 6.6-fold (95% CI: 2.4-7.9) increased risk associated with the combined null genotype presents preliminary evidence that the inherited absence of this carcinogen detoxification pathway may be an important determinant of AML.

We report a case in which the interaction of heterozygosis for both the ß 0 -IVS-II-1 (G→A) mutation and the ααα anti-3.7 allele was the probable cause for the clinical occurrence of thalassemia intermedia. The propositus, a 6-year-old Caucasian Brazilian boy of Portuguese descent, showed a moderately severe chronic anemia in spite of having the ß-thalassemia trait. Investigation of the α-globin gene status revealed heterozygosis for α-gene triplication (ααα/αα). The patient's father, also presenting mild microcytic and hypochromic anemia, had the same α and ß genotypes as his son, while the mother, not related to the father and hematologically normal, was also a carrier of the ααα anti-3.7 allele. The present case emphasizes the need for considering the possibility of α-gene triplication in ß-thalassemia heterozygotes who display an unexpected severe phenotype. The ß-thalassemia mutation found here is being described for the first time in Brazil.

The process of hair cell damage and death as a result of exposure to noise and ototoxins seems to be mediated by reactive oxygen species.Aim: To investigate the relationship between genetic polymorphisms in the Glutathione S-transferase and the susceptibility to hearing loss induced by aminoglycosides. Materials and Methods:Null genotypes were analyzed by multiplex-PCR in the DNA samples from 50 patients and 72 controls. The patients were divided into 3 groups, 10 with hearing loss using aminoglycosides (group A), 20 with hearing loss without exposure to the drug (group B) and 20 hearing individuals who used the antibiotic (group C). Study Design: Experimental.Results: Polymorphisms in the GSTM1 and GSTT1 genes were found in 16% and 42% of patients and in 18% and 53% of the control group, respectively. After statistical analysis no significant difference was observed between the control groups and A (p=0.86) and (p=0.41), controls and B (p=0.27) and (p=0.24), controls and C (p=0.07) and (p=0.47), controls and A + C (p=0.09) and (p=0.47), C and A (p=0.32) and (p=0.75), GSTT1 and GSTM1, respectively. Conclusion:Our data show that polymorphisms in GSTM1 and GSTT1 genes have no influence on the ototoxicity of aminoglycosides. Braz J Otorhinolaryngol. 2010;76(3):306-9. ORIGINAL ARTICLE BJORL

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More than 700 hemoglobin (Hb) structural variants have been described. Most of those were originally detected by their abnormal electrophoretic pattern. They may or may not result in clinical manifestations. A significant proportion of these variants is caused by substitutions which do not change the electrical charge of the protein (1).The present work describes a new electrophoretically silent Hb variant detected by globin chain electrophoresis in a 4-year-old Caucasian Brazilian boy of Italian descent, and in his mother. This new variant has been identified as P34(B16)Val-+Met, and was found in association with Hb Hasharon [a47(CES)Asp+His] and a-thalassemia-2 (a-thal-2) (_a3 ', rightward deletion).