RESUMO
Objetivo:
Avaliar a freqüência e o tipo de mutação no gene “trabecular meshwork-induced glucocorticoid response protein” (MYOC/TIGR) entre pacientes com glaucoma primário de ângulo aberto (GPAA) e glaucoma juvenil de ângulo aberto (GJAA).
Métodos:
DNA genômico foi extraído a partir de sangue periférico de pacientes com GPAA e GJAA. Posteriormente foram realizados PCR e SSCP para identificar possíveis mutações no gene MYOC/TIGR, os quais foram confirmados por meio de análise por sequenciamento.
Resultados:
Foram estudados dezenove pacientes com GJAA. Oito pacientes (42%) apresentaram uma mutação de ponto no codon 433 (exon 3), ocasionando a substituição de uma cisteína (TGT) por uma arginina (CGT). Entre os pacientes com GPAA (n = 52), foram encontrados dois (3,8%) com mutação no gene MYOC/TIGR. Um deles mostrou uma mutação de ponto no aminoácido 368, substituindo uma glutamina por um codon de terminação e o outro paciente apresentou a mesma mutação observada nos pacientes com GJAA.
Conclusão:
Identifícou-se uma nova mutação no gene MYOC/ TIGR em pacientes brasileiros com GPAA e GJAA. A ocorrência de mutações no gene MYOC/TIGR em 42% dos pacientes com GJAA assim como em 3,8% dos pacientes com GPAA poderia ser maior, uma vez que o gene não foi estudado em sua totalidade (apenas 400 pb do exon 3).
Palavras-chave:
Glaucoma juvenil; Glaucoma primário de ângulo aberto; Gene MYOC; Gene TIGR
SUMMARY
Purpose:
To evaluate the frequency and type of mutation in the trabecular meshwork-induced glucocorticoid response protein (MYOC/TIGR) gene among Brazilian patients with juvenile open angle glaucoma (JOAG) and primary open angle glaucoma (POAG).
Methods:
The genomic DNA of consecutive patients with POAG and JO AG was extracted from peripheral blood. Subsequently, PCR and SSCP were performed to identify possible mutations in the MYOC/TIGR gene, which were confirmed by sequencing analysis.
Results:
Nineteen patients with JOAG were studied. Eight patients (42%) showed a single mutation in exon 3 at amino acid 433, which codifies an arginine (CGT) instead of a cysteine (TGT). Among patients with POAG (n = 52), we found two (3.8%) with a mutation in the MYOC/TIGR gene. One of them showed a point mutation at amino acid 368, codifying a stop codon instead of a glutamine. The other patient had the same mutation as those observed in JOAG patients.
Conclusion:
A new mutation in the MYOC/TIGR gene in Brazilian patients with JOAG and POAG was reported. The ocurrence of mutations in the MYOC/TIGR gene in 42% of Brazilian patients with JOAG as well as in 3.8% of those with POAG could be even higher, since the full gene was not evaluated (only 400 bp of exon 3).
Keywords:
Juvenile glaucoma; Primary open angle glaucoma; MYOC gene; TIGR gene
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Datas de Publicação
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Publicação nesta coleção
Dez 1998