Frecuencia del síndrome de X frágil en niños y niñas con autismo del Hospital Vicente Corral Moscoso, Cuenca, 2023

Abstract

Fragile X syndrome is a genetic condition, which is linked to the X chromosome, so it affects more males than females. This hereditary disease is caused by a complete mutation in the X chromosome, in the region Xq27.3, causing the expansion of the cytosine-guanine-guanine trinucleotide (CGG) in the X chromosome mental retardation gene 1 called FMR1, which is responsible for producing the X chromosome mental retardation protein (FMRP) necessary to regulate neuronal structural changes for proper brain development. FXS has disease-specific features, according to the number of CGG triplet repeats, although features or absence of features may be present in the premutation of the syndrome. The quantification of the characteristics requires the application of techniques such as the Polymerase Chain Reaction and Southern blot, the PCR specializes in the repetitive sequence (CGG) of the FMR1 gene, the Southern blot technique in the exploration of the FMR1 gene. This complementarity between both allows a more exhaustive and detailed evaluation. This condition produces a loss of expression of the FMR1 gene and affects the individual's social skills, intellectual disability, learning processes, memory, and behavior. Therefore, at the clinical level, FXS shares similar characteristics with Autism Spectrum Disorder (ASD). Therefore, current medical guidelines mention that any child diagnosed with autism should rule out a possible Fragile X syndrome.