A rare chromosomal anomaly syndrome resulting from a partial deletion of the long arm of chromosome 10. The disease has a highly variable phenotype with principle characteristics of developmental delay (usually of language and speech), variable cognitive impairment, autism spectrum disorder and attention deficit disorder. Macrocephaly and mild dysmorphic features may by associated. Overlap with other syndromes, such as Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome and juvenile polyposis syndrome has been reported. [from SNOMEDCT_US]