After the whole-exome analysis of all core family members and an unaffected aunt revealed a AP3D1 p.V711I (2131G > A) segregating with the disease, further examinations unveiled additional neurological symptoms and immunological aberrations that were reminiscent of HPS10 but largely subclinical and showing both variable penetrance and expressivity. Here, AP3D1 is linked to Hermansky-Pudlak syndrome 10.