Burnside-Butler syndrome, also known as 15q11.2 BP1-BP2 microdeletion, is a congenital disorder caused by microdeletion of DNA sequences involving four neurodevelopmental genes (TUBGCP5, CYFIP1, NIPA1, NIPA2). It is associated with a number of developmental and psychiatric disorders, however, not all individuals are clinically affected; although more studies are needed to delineate the range of clinical presentation.
The 15q11.2 BP1–BP2 microdeletion (Burnside-Butler syndrome) was the most common cytogenetic abnormality found in a recent study of 10,351 consecutive patients presenting for genetic laboratory testing using ultra-high resolution chromosomal microarray analysis optimized for neurodevelopmental disorders and having autism spectrum disorders (ASD). It may represent an under-recognized contributor to the global prevalence of ASD. ASD is a common clinical manifestation of many rare genetic disorders, many of which can be identified by chromosome microarray analysis. The 15q11.2 BP1-BP2 microdeletion accounted for 9% of the top 85 genetic findings associated with neurodevelopmental disorders followed by the proximal 16p11.2 deletion syndrome (5%).