» Are there different types of Cornelia de Lange Syndrome?

Yes. Some children are much more severely affected by the syndrome than others with a wide variation from severe to mild. We now term the more severely affected as "Classic" and the milder people as "Mild" de Lange Syndrome. However, there are clearly defined features that are used in clinically diagnosing CdLS. Please refer to the Treatment Guidelines for the clinical scoring parameters that define a patient  as CdLS.