How is it diagnosed?
The diagnosis of classic Rett Syndrome (RTT) rests on clinical diagnosis criteria. Doctors clinically diagnose RTT by observing signs and symptoms and conducting ongoing evaluations of the girl’s physical and neurological status.
A highly specific set of guidelines (available here) should be used in order to clinically diagnose RTT. These guidelines are divided into three types of clinical criteria:
Are not required although are often present in typical RTT. A girl with these symptoms but without any of the main criteria hasn’t RTT.
The presence of any of the exclusion criteria denies a diagnosis of classic RTT.
Nevertheless, observing signs and symptoms is not always enough to diagnose RTT, especially in the early stages. The availability of genetic testing, which involves examining for the MECP2 mutation on the girl’s X chromosome; may lead to early confirmation of a clinical suspicion of RTT in an infant girl.