Children of Alzheimer's-stricken parents face higher risk

Children of parents who have both been diagnosed with Alzheimer's disease (AD) are at an increased risk of developing the memory-robbing illness, according to a new study carried out by researchers at the University of Washington in Seattle.

The study, appearing in March's Archives of Neurology, looked at children of 111 couples with Alzheimer's disease and compared them directly to children of parents who did not have Alzheimer’s disease, the most common form of dementia among the elderly.

The researchers found that 22.6 percent of the total group of 297 children had developed Alzheimer's disease compared with an estimated 6 percent to 13 percent of the general population.

They also found that out of the 98 men and women who were at least 70 years old, 41 of them or about 42% developed the disease. Among offspring older than 60, more than 30% were affected.

"Of the 240 unaffected individuals, 189 (78.8 percent) had not yet reached age 70 years, suggesting that the incidence of Alzheimer's disease (22.6 percent) is an underestimation of the final incidence rate of Alzheimer's disease in this population," the study says.

Besides the parents, if other family members also develop Alzheimer's disease, the children’s risk of developing the condition did not increase, but they were more likely to develop the disease at younger stage.

Children with no history of the disease beyond the parents usually developed the disease at age 72 compared with those who had one parent with family history of Alzheimer's (60 years) or both parents with family history of the illness (57 years), the researchers found.

"The role of family history and the specific genes involved in this phenomenon require a better definition," the study concludes. "Families with a significant Alzheimer's disease history may be more likely to be referred to an Alzheimer's disease research center and, thus, the present patients may be 'enriched' for a particularly Alzheimer's disease-prone subgroup. Following these families as the offspring continue to age will provide increasingly informative data."

Alzheimer’s is mainly a neurological disorder where a person slowly and progressively starts loosing his memory due to gradual loss of brain cells. It is the most common form of dementia (loss of intellectual ability) and is the fourth leading cause of deaths in adults according to National Institute of Health (NIH).

Alzheimer's affects almost half of all patients with dementia. The most striking early symptom of Alzheimer’s is loss of short term memory. As the disorder progresses, cognitive injury extends to the domains of language (aphasia), skilled movements (apraxia), recognition (agnosia), and those functions (such as decision-making and planning) closely related to the frontal and temporal lobes of the brain.

AD is a progressive brain disease that destroys patients' memories and capacity for speech. The disease is characterized by the development of unusual clumps of proteins called amyloid plaques and nerve cell tangles that hinder messages being processed by the brain.

In 2004, Alzheimer’s was the 7th leading cause of death in USA, with 65,829 numbers of deaths. It is the third most costly disease in the U.S., after heart disease and cancer. According to the Alzheimer's Association, nearly 4.5 million people in the United States currently suffer from the illness.

According to statistics, there are about 24 million people with dementia worldwide, and it has been projected that by 2040, the number of people suffering from AD will increase to 81 million. Globally, there are about 60% people in the developing countries affected by Alzheimer’s and by 2040; this proportion will rise to 71%.