Chromosome 14 familial Alzheimer's disease:: the clinical and neuropathological characteristics of a family with a leucine→serine (L250S) substitution at codon 250 of the presenilin 1 gene

Background-Seven affected members are described from a kindred with autosomal dominant familial Alzheimer's disease associated with a novel mutation in the presenilin 1 (PS1) gene on chromosome 14 that results in a leucine to serine substitution at codon 250 (L250S). Method-Clinical information on the pedigree was collected directly from family members including affected members and their carers and also from hospital records. Results-Detailed clinical information was available on five members. All had an early age at onset with a median age of 52 (95% confidence interval (95% CI) 49.4-54.9). Age at onset varied between 49 and 56 years, with duration of illness varying between six years and 15 years. Myoclonus, depression, and psychosis were features of this pedigree; seizures were not reported. Conclusions-PS1 L250S familial Alzheimer's disease is an early onset form of Alzheimer's disease with clinical features similar to other reported familial Alzheimer's disease pedigrees, except that seizures were absent.