For the most common genetic disorders (e.g., Down Syndrome, Turner Syndrome, SMA1, Prader-Willi Syndrome, Rett Syndrome, Noonan Syndrome, Cornelia de Lange Syndrome, Rubinstein-Taybi Syndrome, Duchenne Muscular Dystrophy and Silver-Russell Syndrome) specific growth charts are generally available. Here, SMN1 is linked to atypical Rett syndrome.