de Villiers C

Heckmann JM

Kalaria RN

Low WC

Morris CM

Ramesar RS

Rao H

Rutherfoord S

Vorster A

Genetically determined Alzheimer\u27s disease (AD) is virtually unknown in Africa. We report clinicopathological findings and a presenilin 1 (PS1) mutation associated with early-onset AD in a large Xhosa family from Southern Africa. Twelve individuals spanning four generations were affected, four of whom underwent clinical and psychometric evaluation. Their phenotype was characterized by memory impairment beginning in the early part of the fifth decade, with progressive dementing illness lasting 6-7 years that did not appear to be modified by the presence of an apolipoprotein E (APOE)-epsilon4 allele. Initial linkage-based analysis using known DNA markers suggested allele cosegregation with a locus on chromosome 14. Direct sequencing of the PS1 gene disclosed a novel I143M (ATT to ATG at nucleotide 677) mutation that lies in a cluster in the second transmembrane domain of the protein. Examination of the proband\u27s brain at autopsy revealed severe AD pathology characterized by neuronal loss, abundant beta amyloid (Abeta) neuritic plaques (Abeta42) and neurofibrillary degeneration extending into the brainstem. The phenotype of the I143M mutation was clearly associated with a high degree of neurofibrillary change compared with early-onset sporadic AD cases. Although sporadic cases of AD do exist in African populations, our study confirms the existence of early-onset familial AD among indigenous Southern Africans

Newcastle University E-Prints

Novel presenilin 1 mutation with profound neurofibrillary pathology in an indigenous Southern African family with early-onset Alzheimer\u27s disease

Novel presenilin 1 mutation with profound neurofibrillary pathology in an indigenous Southern African family with early-onset Alzheimer\u27s disease

Abstract

Similar works

Full text

Available Versions

Newcastle University E-Prints