TableĀ 2

Screening methods: initial diagnostic tests leading to the diagnosis in 101 patients

Initial test%
Urinary Cr to Crn ratio39
Urinary Cr to Crn ratio and MRS4
DNA testing familial mutation14
DNA sequencing*10
  • *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.