APBA1 and early-onset autosomal dominant Alzheimer disease: Other gene-based hits linked to neurobiological pathways include: Ataxin2-like (ATXN2L) on chromosome 16 (a member of the spinocerebellar ataxia family which is associated with neurodegenerative disorders); amyloid beta (A4) Precursor Protein-Binding, Family A, Member 1(APBA1) on chromosome 9, which interacts with the Alzheimer's disease amyloid precursor protein;50 and SH2B Adaptor Protein 1 (SH2B1) on chromosome 16, previously associated with type 2 diabetes.51