15q11.2 BP1-BP2 microdeletion presenting as progressive spastic paraplegia and brain images of small vessel disease

15q11.2 BP1-BP2 microdeletion is related to clinical abnormalities including general developmental delay, speech and neuropsychiatric disorders, which is known as Angelman syndrome. However, the clinical penetrance and phenotype of 15q11.2 BP1-BP2 deletion is varied and confusing. Herein, we retrospectively described a 50-year-old male patient who manifested with progressive spastic paraplegia of lower limbs and episodic exacerbation. While brain MRI showed white matter hyperintensities, lacunes, cerebral microbleeds, enlarged perivascular spaces, and brain atrophy, mimicking small vessel disease. Next-generation sequencing combining multiplex ligation-dependent probe amplification identified a 253 kb 15q11.2 BP1-BP2 microdeletion, encompassing 4 conserved imprinted genes (NIPA1, NIPA2, CYFIP1 and TUBGCP5). This report will build new connections among spastic paraplegia, small vessel disease and 15q11.2 BP1-BP2 microdeletion.