The first case series of Chinese patients in Hong Kong with familial Alzheimer's disease compared with those with biomarker-confirmed sporadic late-onset Alzheimer's disease.

INTRODUCTION

Patients with familial Alzheimer's disease are being increasingly reported in Hong Kong. The objectives of this study were to report the clinical features of these patients, and to compare them with those with biomarker-confirmed sporadic late-onset Alzheimer's disease.

METHODS

All symptomatic Chinese patients with familial Alzheimer's disease who attended Queen Mary Hospital, Memory Clinic between January 1998 and December 2016 were included. Information about clinical features, baseline Mini-Mental State Examination score, and presenting cognitive symptoms or atypical clinical features were collected. Their clinical features were compared with those of 12 patients with sporadic late-onset Alzheimer's disease with cerebrospinal fluid biomarker evidence of Alzheimer's disease and 14 patients with late-onset Alzheimer's disease and positive amyloid loading on Pittsburgh compound B imaging.

RESULTS

There were three families with familial Alzheimer's disease among whom eight family members were affected. The mean (± standard deviation) age of onset and the Mini-Mental State Examination score were 48.4 ± 7.7 years and 7.9 ± 9.2, respectively. Compared with the sporadic late-onset Alzheimer's disease patients, those with familial Alzheimer's disease had an earlier age of onset and presentation (both P<0.001) and received the correct diagnosis later (median [interquartile range], 7.5 [5.3-14.5] vs 2 [1.0-3.3] years; P<0.001). Patients with familial disease had a lower Mini-Mental State Examination score at presentation than those having late-onset Alzheimer's disease (mean, 7.9 ± 9.2 vs 17.6 ± 7.2; P=0.01). They also had fewer delusions, and less dysphoria and irritability (0% vs 41.7%, 0% vs 50% and 0% vs 54.2%; P=0.04, 0.01 and 0.01, respectively). There was a trend of less frequent amnesia among patients with familial Alzheimer's disease compared with those having late-onset Alzheimer's disease (75% vs 100%; P=0.05).

CONCLUSION

Clinical features differ for patients with familial Alzheimer's disease compared with those with late-onset Alzheimer's disease. There is a delay in diagnosis. Promotion of public awareness of familial Alzheimer's disease is much needed.