• Turnaround time:
    10–21 calendar days (14 days on average)
  • Preferred specimen:
    3mL whole blood in a purple-top tube
  • Alternate specimens:
    DNA or saliva/assisted saliva
  • Sample requirements
  • Request a sample kit



CCDS1; CRT; CRTR; CT1; CTR5; Creatine Transporter SLC6A8; Creatinine transporter; Sodium- And Chloride-Dependent Creatine Transporter 1; Solute Carrier Family 6 Member 8

Associated disorders

The SLC6A8 gene is associated with X-linked recessive creatine transporter deficiency (CTD) (MedGen UID: 337451).

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Invitae tests that include this gene:

Pathogenic variants in the SLC6A8 gene are associated with ~90% of clinical cases of creatine transporter deficiency syndrome.

Creatine is an essential cofactor in cellular energy production and utilization. Creatine is taken up from food as well as synthesized in the body. The SLC6A8 gene encodes a creatine transporter that is important for uptake of dietary creatine and transfer of creatine between cells and organs (PMID: 21308988).

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence in the transcript listed below. In addition, analysis covers the select non-coding variants specifically defined in the table below. Any variants that fall outside these regions are not analyzed. Any specific limitations in the analysis of these genes are also listed in the table below.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
SLC6A8 NM_005629.3