Reacción a "A single copy of a protective gene variant helps delay early Alzheimer's disease"

It is a quality and relevant study, conducted in a cohort of subjects unique in the world, such as those affected by the paisa mutation (mutation in the presenilin1-PSEN1 gene), which is very prevalent in the Antioquia region of Colombia and which gives rise to Alzheimer's disease with onset in the 40s.  

Some time ago, they published a case of a subject with this mutation who was particularly resilient to developing the disease and who was associated with carrying two copies (homozygous) of the Christchurch variant of the ApoE gene. The current study seeks to describe the effect of carrying a single copy (heterozygous) of this ApoE variant in carriers of the mutation in the PSEN1 gene. The findings point to some protective effect (delayed age of onset, less tau pathology and somewhat less neurodegeneration) compared to non-carriers, although the effect is smaller than in the original homozygous case. This points to a gene dosage effect of the Christchurch variant (the more copies, the greater the protective effect). 

The main limitation of the study is that the number of subjects with PSEN1 and carrying this variant is very low (only 27 subjects in the world's largest cohort of PSEN1 mutations, with 1000 subjects, which is a barbarity), so more studies are needed in other populations, both in carriers of mutations in PSEN1 (also different from paisa), and in carriers of other mutations in other genes (PSEN2, APP or APOE e4) and in populations with sporadic Alzheimer's, trying to find out whether this protective effect is maintained and its magnitude.  

The most interesting thing - and the main door it leaves open - is that, if we are able to mimic the effect of this variant using drugs, it would open the door to treatments that may confer protection against the development of Alzheimer's disease.