Alzheimer’s disease: diagnostics, prognostics and the road to prevention

Alzheimer’s disease (AD) presents one of the leading healthcare challenges of the 21st century, with a projected worldwide prevalence of >107 million cases by 2025. While biomarkers have been identified, which may correlate with disease progression or subtype for the purpose of disease monitoring or differential diagnosis, a biomarker for reliable prediction of late onset disease risk has not been available until now. This deficiency in reliable predictive biomarkers, coupled with the devastating nature of the disease, places AD at a high priority for focus by predictive, preventive and personalized medicine. Recent data, discovered using phylogenetic analysis, suggest that a variable length poly-T sequence polymorphism in the TOMM40 gene, adjacent to the APOE gene, is predictive of risk of AD age-of-onset when coupled with a subject’s current age. This finding offers hope for reliable assignment of disease risk within a 5-7 year window, and is expected to guide enrichment of clinical trials in order to speed development of preventative medicines

A mutation in the α tropomyosin gene TPM3 associated with autosomal dominant nemaline myopathy

Nemaline myopathies are diseases characterized by the presence in muscle fibres of pathognomonic rod bodies. These are composed largely of alpha−actinin and actin. We have identified a missense mutation in the alpha−tropomyosin gene, TPM3, which segregates completely with the disease in a family whose autosomal dominant nemaline myopathy we had previously localized to chromosome 1p13−q25. The mutation substitutes an arginine residue for a highly conserved methionine in a putative actin−binding site near the N terminus of the alpha−tropomyosin. The mutation may strengthen tropomyosin − actin binding, leading to rod body formation, by adding a further basic residue to the postulated actin−binding motif