Molecular (DNA) test to confirm a diagnosis of creatine transporter deficiency syndrome when Creatine Transporter Deficiency (SLC6A8) Sequencing (2008615) does not identify a causative mutation. Carrier testing for individuals with a family history of a deletion or duplication in the SLC6A8 gene.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 2 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Intellectual disability and seizure disorder of variable severity. May also include speech/language delays, movement disorder, and behavioral disorders such as autism, hyperactivity, and self-injury.
Incidence: Unknown. More than 100 cases have been described.
Cause: Pathogenic SLC6A8 gene mutations.
Clinical Sensitivity: Unknown, possibly 1-2 percent.
Methodology: Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large SLC6A8 coding region deletions/duplications.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Single base pair substitutions, small deletions/duplications, regulatory region mutations and deep intronic mutations will not be detected. Deletion/duplication breakpoints will not be determined. Mutations in genes other than SLC6A8 were not evaluated. Deletions/duplications in exons 2, 3, 5, 7, and 13 will not be detected.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
|Component Test Code*||Component Chart Name||LOINC|
|2008607||SLC6A8 DelDup Specimen|
|2008608||SLC6A8 DelDup Interpretation|