Identification of beta thalassemia mutations in South Brazilians.
We have evaluated the mutation profile in a sample of 127 unrelated beta-thalassemia (beta thal) individuals, diagnosed through A2 and fetal hemoglobin quantification by high-performance liquid chromatography (HPLC) from the Brazilian southernmost state, where a flow of Italian immigrants had occurred in the late 19th century, mainly from Northern Italy. The molecular analysis was performed by DNA sequencing of the most common mutations found in the Mediterranean region. The beta 0 codon 39 nonsense mutation was the most frequent alteration (50.9%), followed by beta+ IVSI 110 G>A (18.1%), beta 0 IVSI 1 G>A (12.9%), beta+ IVSI 6 T>C (9.5%), and other rare mutations (8.6%). The chosen gene sequence was able to identify 91% beta-thal mutations in the population studied, showing some similarity with allele frequencies of the mainly colonizing countries of Rio Grande do Sul state. The comparison of our results to other Brazilian studies has shown significant differences. Therefore, we can conclude that the genotypic profile of beta-thal shows great variability. Hence, it would be arbitrary to infer regional study results as being representative of the Brazilian whole population. Brazilian researchers of different regions should identify their most frequent genotypes to provide better understanding on this disease and state adequate public health policies.
Reichert
Vivian C D
VC
Serviço de Genética Médica-Laboratório de Genética Molecular, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul., Rua Ramiro Barcelos, 2350, Porto Alegre, RS CEP 90035-903, Brazil.
de Castro
Simone M
SM
Wagner
Sandrine C
SC
de Albuquerque
Dulcinéia M
DM
Hutz
Mara H
MH
Leistner-Segal
Sandra
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005914:Globins / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D017086:beta-Thalassemia / Q000453:epidemiology / Q000235:genetics*
D005914:Globins