Robert Bazell writes:
Tonight we profile an extraordinary family, the Heinrichs of Davenport, Iowa. They have a rare gene that will likely afflict some of them with Alzheimer’s disease at an early age. They have been extraordinarily generous volunteering their time for research. Their generosity could help millions around the world.
Long before he was diagnosed with Alzheimer’s in his 40’s, Vince Heinrichs, was a graduate student, who began his own research, when he realized that his family had a high incidence of senility at an early age. He was diagnosed in 1983 and died in 1988. After his death his wife Denise vowed to carry on the research effort which clearly had huge implications for their six children. She has taken her children to labs around the country starting with the National Institute of Health. Today, she is in Paris at the Alzheimer’s Association's annual meeting as part of the group representing the Dominantly Inherited Alzheimer Network (DIAN) study run out of Washington University in St. Louis.
Most cases of Alzheimer’s disease are called “sporadic”. Several genes are known to affect the risk but not make the disease a certainty. But there are three genes APP, PS-1 and PS-2 that determine destiny. The genes are dominant so if a person inherits just one copy from either parent he or she will get Alzheimer’s usually before age 60. Vince Heinrichs carried PS-1 and thus each of his 6 children has a 50/50 chance of having it and if they carry it their children have a 50/50 chance of carrying the gene.
Fortunately these three dominant deterministic genes are rare, affecting only a few hundred families in the world. But the DIAN study focuses on them allowing researchers to know who is going to get Alzheimer’s and follow them closely watching for changes in the brain while trying to discover drugs that will stop or slow the damage.
The first discovery from the DIAN study – out today at the Paris meeting -- is that changes in the brain occur decades before any symptoms of dementia. This could mean that it may be necessary to start treatment that early, but future studies will determine that.
Meanwhile the Heinrichs' face critical decisions. The researchers studying them through coded number know which family members carry the genes and which do not. The family for now has decided not to know the information themselves until there are effective treatments. They also are bracing themselves for the days ahead when according to the odds some of them will get Alzheimer’s. They believe that moment will be harder on those who escape that fate than those who are diagnosed.