If<unk>  is suspected, analysis of the MLL gene can be carried out. Otherwise, it may be diagnosed by whole-exome sequencing or whole genome sequencing. There is limited diagnostic testing in this area. The standard screening tests that take place during pregnancy that can diagnose syndromes such as Down Syndrome do not diagnose WSS. In addition, baseline genetics diagnostic tests conducted after birth do not include testing for WSS. Whole exome sequencing has been used to identify most people with WSS. Often, medical professionals do not offer the option for whole exome testing or the costs associated are not covered by insurance or require a large copay limiting individuals from having the testing done. Frequently, patients are given other incorrect medical explanations or a less specific and broader diagnosis, like autism and Rubinstein–Taybi syndrome. Additionally, once a person reaches a certain age or phase in their lifetime having been mis-diagnosed or gone undiagnosed, he/she may stop looking for answers to their medical trials and tribulations meaning they may never come across a formal WSS diagnosis. There have also been patients with<unk>  who were initially mis-diagnosed with Kabuki syndrome.
Wiedemann–Steiner syndrome
Beckwith–Wiedemann syndrome
Wiedemann–Rautenstrauch syndrome
Laurence–Moon syndrome
Bardet–Biedl syndrome
Wilson–Turner syndrome
Miller–Dieker syndrome
Smith–Magenis syndrome