Creatine Transporter Deficiency (SLC6A8) Sequencing
| Disorder | Creatine Transporter Deficiency | |
| Gene Names | SLC6A8 | |
| Clinical info | 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. | |
| Indications | Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutation within a family to allow for carrier testing and prenatal diagnosis. | |
| Associated Tests | Creatine transporter deficiency biochemical analysis. | |
| Detection | A mutation in SLC6A8 will be indentified in greater than 99% of patients with creatine transporter deficiency. | |
| Specimen Requirements | SLC6A8 testing uses RNA as the starting nucleic acid for analysis. This requires a peripheral blood sample collected in a Qiagen PAXgene Blood RNA tube. As these specialized tubes are not normally available in most clinical settings, please contact the Molecular Diagnostic Laboratory to request a PAXgene Blood RNA tube with enclosed instructions for drawing. (Please note: for optimal results, the specimen must be collected directly into the PAXgene tube. Blood should not be transferred from other Vacutainer tubes into a PAXgene tube.) Another three to five milliliters of whole blood should also be collected in an EDTA Vacutainer (lavender top). | |
| Transport | The specimen should be kept at room temperature and delivered via overnight shipping. FedEx is preferred. Do not freeze the specimen. | |
| Turnaround time | 6 weeks | |
| Prenatal testing | Prenatal diagnosis is available if the familial mutation is 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. | |
| CPT Codes | Unknown mutation 81479 Known mutation 81479 |
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| Cost | $1800 for sequencing $350 for known mutation |
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| Contact | For further information contact This email address is being protected from spambots. You need JavaScript enabled to view it. , MS, Lab Counselor at 1-800-473-9411. | |
Form Needed
Download molecular-lab-request-form.pdf
Have Questions Need Support?
Contact our Laboratory Representative for assistance.
Kellie King, MS, CGC
Molecular Diagnostic Lab
The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.