Report of a patient with fragile X syndrome unexpectedly identified by karyotype analysis

Relato de um paciente com a síndrome do X frágil identificada de forma inesperada por meio do cariótipo

Maiara A. Floriani Marcelo R. Vilas Boas Rafael Fabiano M. Rosa Patrícia Trevisan Luiza Emy Dorfman Rosana C. M. Rosa Tatiana D. Zen Paulo Ricardo G. Zen About the authors


Fragile X syndrome is considered the main known cause of inherited learning disabilities and it is characterized by mutations in the FMR1 gene. Our aim was to report an unexpected detection of a patient with fragile X syndrome by GTG-Banding karyotype analysis (G-bands after trypsin and Giemsa). The karyotype analysis identified Xq27.3 fragility in 17% of the metaphases analyzed and in 54% when using TC 199, consistent with the cytogenetic diagnosis of the syndrome. This case was the sole one to present the fra(X) tests in the high-resolution karyotype analysis in our care service, contributing to future diagnoses of patients with history of developmental delay.

Key words:
karyotype; fragile X syndrome; intellectual disability; chromosomal fragile sites

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