P193 – 2860: Many faces of Rett syndrome: Is there still a diagnostic delay?

Abstract

Objective Rett syndrome is the second most common neurodevelopmental genetic disorder in girls. Major clinical features include developmental regression after a normal period of development, autistic behavior, loss of purposeful hand use, stereotypical hand movements, abnormal breathing pattern, peripheral vasomotor disturbances and seizures. MECP2 gene mutations can be detected in up to 90–95% of patients with classical Rett syndrome. Methods In order to document the clinical course in this syndrome, we have included 15 consecutive patients in whom MECP2 mutations were detected. Results Age range was 3–22 years (median 15 years). First admission to a physician with a suspicion of abnormal development was between 8 months to 4 years. Diagnostic delay on the bedside was calculated as median 1 year (0–3.5 years). Stereotypical hand movements developed between 8 months – 5 years (median 2 years). One patient did not have normal early developmental milestones. Loss of purposeful hand movements was seen between 1–9 years (median 2 years). Of note, in one patient loss occurred at 9 years of age and in another 3-year-old, purposeful hand use was never observed. Microcephaly was detected in 12 patients. During a mean course of 5.7 years (2 months to 18 years), two of the patients lost independent ambulation (6 and 10 years). Other than stereotypical hand movements 5 patients had additional stereotypies including pelvic tilt, truncal rocking motion and spitting behavior. Conclusion Despite recent availability of MECP2 testing, there is still a considerable delay in diagnosis, due to clinical variability in terms of appearance of core symptoms and course.