Analysis of the DMPK gene CTG repeat in healthy Brazilians

Genetics and Molecular Biology

Silvia Regina Sampaio Freitas²  Pedro H. Cabello²  Rodrigo Soares Moura-neto¹  Luiz Alves Duro¹ 

[1] ,Fundação Oswaldo Cruz Departamento de Genética Rio de Janeiro RJ ,Brazil

关键词: myotonic dystrophy;    dynamic mutation;    trinucleotide repeat;    CTG repeat;    DMPK gene;   

DOI  :  10.1590/S1415-47572007000100004

来源: SciELO

【 摘 要 】

Myotonic dystrophy (DM) is a neuromuscular disorder caused by the expansion of the cytosine-thymine-guanine (CTG) repeat of the myotonic dystrophy protein kinase gene (DMPK). This repeat is highly polymorphic in healthy individuals [(CTG)5-37], and it has been proposed that expanded CTG alleles originated from larger sized normal alleles [(CTG)19-37]. According to this hypothesis, a positive correlation should be expected between the frequency of these large-sized normal alleles and the prevalence of the disorder in a population. We determined the distribution of CTG alleles of the DMPK gene in 156 healthy Brazilians from Rio de Janeiro city. Our analyses of 312 chromosomes detected 20 different alleles ranging in size from 5 to 27 CTG repeats, with 24 alleles having more than 18 repeats (7.69%). This frequency of (CTG)3(19) alleles observed in our population suggests that the prevalence of DM in Rio de Janeiro should not be different from the prevalence in European populations.

【 授权许可】

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