Abstract
Background
Two inborn errors of metabolism of creatine synthesis as well as the X-linked creatine
transporter (SLC6 A8) deficiency have been recognized. This report describes the features of five identified
male patients and their female relatives who are carriers of the X-linked creatine
transporter deficiency syndrome.
Methods
Proton MR spectroscopy was used to recognize creatine deficiency in the patients.
Molecular analysis of the SLC6A8 gene was performed, confirming the diagnosis of homozygous males and heterozygous
females.
Results
We describe four families from a metropolitan area in the U. S. with X-linked creatine
transporter deficiency. All affected males present with developmental delay and severe
developmental language impairment. Proton MR spectroscopy shows significantly depressed
to essentially absent creatine and phosphocreatine in the male patients. Nonsense
mutations and amino acid deletions were found in the SLC6A8 gene in the affected families.
Conclusion
Creatine transporter deficiency may be a more common X-linked genetic disorder than
originally presumed. The affected males exhibit mental retardation with severe expressive
language impairment.
Key words
Creatine Transporter Deficiency - Developmental Language Impairment
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M. D., Ph. D. Ton J. deGrauw
Cincinnati Children's Hospital
Division of Neurology
3333 Burnet Avenue
Cincinnati, OH 45229 - 3039
USA
Email: Ton.degrauw@cchmc.org