Fragile-x marker among patients having numerical [autosomal and sex] chromosomal aberrations

As fragile-X syndrome is the 2nd most common chromosomal abnormality causing mental retardation, and aiming to investigate its concurrent occurrence with the most common numerical and sex chromosomal aberration syndromes, this study was conducted to investigate this issue in 43 subjects [Down syndrome, 20, and Klinefelter, 14, and Turner, 9]. Results showed that overall, fra-[X] marker was observed in only one of the Klinefelter syndrome subject and in none of the Down syndrome or Turner syndrome subjects. This adolescent case showed increased urinary homocystine level, compared with other members of Klinefelter group. This metabolic finding may explain his aberrant symptomatology