The creatine transporter (CRTR) defect is a recently discovered cause of X-linked intellectual disability for which treatment options have been explored. Creatine monotherapy has not proved effective, and the effect of treatment with L-arginine is still controversial. Nine boys between 8 months and 10 years old with molecularly confirmed CRTR defect were followed with repeated1H-MRS and neuropsychological assessments during 4-6 years of combination treatment with creatine monohydrate, L-arginine, and glycine. Treatment did not lead to a significant increase in cerebral creatine content as observed with H1-MRS. After an initial improvement in locomotor and personal-social IQ subscales, no lasting clinical improvement was recorded. Additionally, we noticed an age-related decline in IQ subscales in boys affected with the CRTR defect.

doi.org/10.1007/s10545-011-9345-1, hdl.handle.net/1765/25734
Journal of Inherited Metabolic Disease
Erasmus MC: University Medical Center Rotterdam

van de Kamp, J. M., Pouwels, P. J. W., Aarsen, F., ten Hoopen, L. W., Knol, D. L., de Klerk, J., … Mancini, G. (2012). Long-term follow-up and treatment in nine boys with X-linked creatine transporter defect. Journal of Inherited Metabolic Disease, 1–9. doi:10.1007/s10545-011-9345-1