Potocki-Shaffer syndrome is a contiguous gene deletion syndrome involving 
11p11.2p12 and characterized by multiple exostoses, biparietal foramina, 
genitourinary anomalies in males, central nervous system abnormalities, 
intellectual disability, and craniofacial abnormalities. Current literature 
implicates haploinsufficiency of three genes (ALX4, EXT2, and PHF21A) in causing 
some of the cardinal features of PSS. We report a patient with multiple 
exostoses, biparietal foramina, and history of mild developmental delay. 
Cognitive and behavioral testing supported formal diagnoses of anxiety, verbal 
dyspraxia, articulation disorder, and coordination disorder, without 
intellectual disability. His facial features, though distinctive, were not 
typical of those observed in PSS. As the chromosomal deletion does not encompass 
PHF21A, this case lends further support that haploinsufficiency of PHF21A 
contributes to the intellectual disability and craniofacial abnormalities in PSS 
and that there are other genes in the region which likely contribute to the 
behavioral phenotype in this syndrome. © 2017 Wiley Periodicals, Inc.