15q11.2 microdeletion - seven new patients with delayed development and/or behavioural problems.

15q11.2 microdeletion has been suggested as a new microdeletion syndrome and several patients have been described in the literature. We report seven new patients belonging to six families, age 9-24 years old, with a 350 kb 15q11.2 deletion of the four highly conserved genes (TUBGCP5, NIPA1, NIPA2 and CYFIP1) earlier reported. All our patients had some degree of learning difficulties, delayed development and/or behavioural problems. Common dysmorphic features and congenital malformations were not characteristics of our patients. The deletion was inherited from a mildly affected parent in all cases tested (5/6 families available for testing both parents). These seven new cases confirm some of the features earlier reported to be associated with 15q11.2 deletion, and help to further delineate the phenotype associated with 15q11.2 deletion.