Alzheimer's disease

[Name of the institute]How the Mutations in Presenilin 2 Lead to Alzheimer's disease

Introduction

Alzheimer's disease is a neurodegenerative disease that affects approximately 15 million people worldwide. It was first described in 1906 by Dr. Alois Alzheimer who identified two brain lesions characteristic of the disease in specific brain regions, the hippocampus and the cerebral cortex. These two characteristics are manifested in the form of extracellular senile plaques, which consist mainly of a fragment of 42 amino acids, ß-amyloid and intracellular neurofibrillary tangles caused by hyperphosphorylation of tau. All of these effects on the brain cause neuronal death and synaptic massive resulting in the gradual appearance of patient symptoms affecting memory, behavior, speech, and movement etc.

The diagnosis of Alzheimer's disease is mainly based on the examination, testing neuropsychological and highlighting of atrophy cortical that touches the temporal lobe and internal including the hippocampus, regions important for memory. It is usually diagnosed after the age of 65 years. Early forms, rare (less than 5% of patients), however, can occur much earlier. The first signs of Alzheimer's disease are often confused with the normal aspects of aging, a depression, a stress or other diseases neurological as vascular dementia. It was thus under-diagnosed until the 1960s. The speed and course of the disease varies from one individual to another, which makes it difficult to forecast accurate. The life expectancy varies so 3 to 8 years depending on the patient's age at diagnosis. With the progression of the disease, patients may suffer from rejection by society and their families.

There is currently no treatment that reduces the progression of this disease. The treatments offered are mainly of palliative and have a limited effect on symptoms. Cognitive stimulation, exercise and a balanced diet may delay the onset of cognitive impairment in the elderly. Since Alzheimer's disease cannot be cured and is degenerative, the patient relies on others for help. The role of the main caregiver is essential. Alzheimer's disease affected about 26 million people worldwide in 2005, and could reach four times in 2050, which is equivalent to 1 person in 85. In developed countries, AD is one of the most costly diseases to society.

Given the prevalence of the disease, a significant effort is led by medical research to discover a drug that would stop the neurodegenerative process. The main line of research aims to address the amyloid plaques that form between neurons during the disease and aggregates tau forming neurofibrillary tangles inside neurons.

Alzheimer's disease is hereditary and sporadic. However, the majority of cases of Alzheimer's disease are called sporadic; they are not hereditary, although, the presence of certain genes is a risk factor. However, about 0.1% of cases are familial genetic forms with autosomal dominant (not sex-linked) that usually trigger to 65 years. This form of the disease is known as familial Alzheimer's disease early (Early onset familial Alzheimer's disease).

The causes of the development of the disease differ in both cases despite the joint appearance of the two types of lesions characteristic of the disease and symptoms ...