Introduction

Classic (or typical) CdLS can be easily recognised from birth by an experienced children’s doctor (paediatrician) or clinical geneticist (a doctor who diagnoses and supports families with genetic disorders). This is because individuals with CdLS often have distinctive facial features, growth patterns, and limb differences. These characteristics form the classic CdLS phenotype, which the physical, cognitive and behavioural characteristics associated with the syndrome.

The wider CdLS spectrum includes the classic (typical) CdLS phenotype, alongside similar but non-classic (atypical) characteristics of CdLS, which are caused by changes in genes associated with CdLS.

But looking Classical or non-typical CdLS (phenotype) does not say everything about cognitive abilities. We know classic looking CdLS people with very good development and non-typical CdlS people with severe delays in development.