Parents

Rett Syndrome (RTT) has been described by Andreas Rett about 50 years ago. RTT is a multi-system disorder showing specific clinical characteristics and stages.

First described mutation of this syndrome is in MECP2 gene. MECP2 gene has been discovered 30 years after first description of RS, giving rise to detailed molecular studies.

Main clinical features
Delay-in gross motor skills, autistic features, seizures, loss of purposeful hand use, loss of ambulation.

Incidence and Prevalence
Incidence of RTT is between 1:10.000-20.000 while prevalence of RTT is 1 in 20.000-40.000.

Inheritance
X-linked dominant.

Age of onset
Mostly infancy.

Molecular characteristics
Variants in the MECP2 gene cause 95% of typical RTT cases and up to 73% of atypical RTT cases.

Genetic counselling
RTT is an X-linked dominant disorder. Which means that mothers with such genetic load, both female and male children have 50 % equal chance to have the disease. Some pathogenic variants of MECP2 may also affect males with a wide range of neurological manifestations between much milder cases than classical RTT and severe neonatal encephalopathy making the diagnosis complicated.

Management
A multidisciplinary approach including anti-seizure medicine and targeting associative endcrinological and orthopedic problems is necessary.