Researchers identified three gene variants linked to the timing and progression of inherited Alzheimer's. ...Each appeared to modify Alzheimer's risk or progression independent of the underlying inherited mutation. The researchers also found that a variant in RHOJ was associated with biological markers of more severe Alzheimer's disease. The results add to a growing body of evidence that genes beyond the well-known Alzheimer's risk factors can influence how the disease unfolds. Identification of genetic modifiers of autosomal dominant Alzheimer's disease: a genome-wide association study.