The Genetic Characteristics Of A Chinese Early-onset Alzheimer’s Disease Family

Background and aimsAlzheimer’disease(AD) is one of the neurodegenerative disease in the old population, mainly manifesting memory loss, personality or behavior change, disorientation and the like.patient affected it usually dies of pneumonia or urinary infection. AD can be classified into early-onset AD(EOAD)(usually<60) and late-onset AD(LOAD)(usually≥60) according to the age at onset. EOAD can also be called as early-onset familial AD(EOFAD) for these patients exposed to doctors usually clustered in a family with a character of autosomal dominant inheritance, while LOAD can be as sporadic AD(SAD) because of the lack of phenomenon of clustering. APP, PS1, PS2 gene mutation account for the most common mechanism underlying EOFAD. PS1 gene is the majority. In china, few genetic and clinical materials about EOFAD have been shared. aChinese Alzheimer’ disease family was checked in our hospital. We aimed to collect clinical materials of familial members and perform DNA sequencing to identify the gene contributing to the EOFAD.Materials and methods1. Collect the demographic data of all the family members. inquiry the patients suffered AD on the development of the disease, history of other disease, history of operation and the like. Check the whole body and nervous system. Performed MMSE, CDR, FOM, RVR, HIS and other neuropyscological evaluations. besides, brain MRI or CT and blood tests would becarried out.2. Collect blood sample of the patient with EDTA anticoagulation tube, extract DNA from blood with Wizard®Genomic DNA Purification Kit, then send to perform DNA sequencing.Results1. Patients within this family carried a base changefrom T to G at the site 314 in the prsenlin 1 gene, resulting in a Phe to Cys substitution at codon 105(F105C), while the cognitively normal family members and the common population did not harbor this mutation.2. Family members affected AD presented memory loss at age of 50 years or so, which is content with reports about the same site; But theydidn’t present Parkinson-like syndrome as previous description.Conclusionsweconfirmed a new mutation of F105 C in the PS1 gene within a Chinese EOFAD family.The patients presented memory loss at age of 50 years or so, with multiple cognitions deteriorating and social function losing gradually.we added a new mutation to the sea ofgenetic mutations in EOFAD and provided a significant groundwork for exploring mechanism underlying EOFAD.