Markedly increased platelet membrane fluidity in Down syndrome with a (14q, 21q) translocation

Abnormal platelet membrane fluidity was found in a 50-year-old woman with Down syndrome who had been experiencing a gradual mental decline. The patient's karyotype showed a triplication of the long arm of chromosome 21. The authors hypothesize that the PMF-locus, which carries the allele for increased membrane fluidity, is located on the long arm of chromosome 21. Similarities between Down syndrome and Alzheimer's disease and the possible relationship between membrane fluidity and cognitive function are mentioned.