Amyloid PET pattern with dementia and amyloid angiopathy in Taiwan familial AD with D678H APP mutation.

Introduction: The novel D678H amyloid precursor protein (APP) gene mutation has been called the "Taiwan mutation". The study aims to identify amyloid deposition patterns and clinical features associated with this mutation.

Methods: we analyzed the clinical manifestations, brain neuroimages and F-AV-45 positron emission tomography (PET) findings in symptomatic patients and asymptomatic subjects with the autosomal-dominant Alzheimer's disease (AD). We compared the amyloid deposition pattern among 10 patients with genetically-positive familial cognitive decline (CD), 18 patients with sporadic CD, and 19 healthy controls.

Results: The clinical features were the early onset of memory impairment in all 10 patients and cerebral amyloid angiopathy in 3 patients. The characteristic results of brain F-AV-45 PET included the highest standard uptake value ratio (SUVR) in the occipital and cerebellar cortical areas in the genetically-positive CD patients. In subgroup analysis, the familial AD patients had a decreased amyloid SUVR trend in most areas except for cerebellar cortex compared to those with familial mild cognitive impairment.

Conclusion: Our data indicate that the familial D678H gene mutation have resulted in a more potent amyloid burden than in the patients with sporadic AD patients. The high amyloid uptake in the occipital area is characteristic of the specific Taiwan APP gene.