Creatine Transporter Deficiency: SLC6A8 Sequencing

SLC6A8 sequencing is a molecular test used to identify variants in the gene associated with Creatine Transporter Deficiency.

Turnaround Time

6 weeks

CPT Code(s)

81479

Cost

$1,500

Genes

• Creatine Transporter Deficiency

Creatine transporter deficiency is an X-linked disorder caused by to mutations in the creatine transporter gene (SLC6A8; CTR1) localized to Xq28. Males can present with speech and developmental delay, seizures and hypotonia. Carrier females can have a mild intellectual impairment and problems with social skills. Males show a significant elevation in urinary creatine excretion and may have a mild elevation of plasma creatine. Creatine uptake studies or molecular analyses are recommended to confirm positive biochemical findings.

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Sanger Sequencing

A mutation in SLC6A8 will be indentified in greater than 99% of patients with creatine transporter deficiency.

This test requires a Qiagen PAXGENE tube and purple top (EDTA) tube. PAXGENE tubes available upon request.

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.