EHMT1 and arachnoid cyst: The heterozygous microdeletion in 9q34.3 involving the EHMT1 gene confirms the diagnosis of KS.<h4>Comments</h4>The presence of pathogenic CNVs and/or those of uncertain significance, located on chromosomes 2, 6 and Y, may be contributing to a variability in the patient's clinical condition (arachnoid cyst, single palmar fold and ligament laxity), compared to other individuals with only KS genetic alteration, making the dignosis of the disease harder.