Screening methods: initial diagnostic tests leading to the diagnosis in 101 patients
| Initial test | % |
|---|---|
| Urinary Cr to Crn ratio | 39 |
| MRS | 21 |
| Urinary Cr to Crn ratio and MRS | 4 |
| DNA testing familial mutation | 14 |
| DNA sequencing* | 10 |
| Unknown | 12 |
*Performed in research cohorts of (X-linked) intellectual disability (n=9) or because of suspicion of CRTR-D based on clinical features (n=1).
Cr to Crn, creatine to creatinine; CRTR-D, creatine transporter deficiency; MRS, MR spectroscopy.