These genes are called C9orf72, SOD1, FUS and TARDBP. There are a growing number of other genes which have been associated with MND (more than 20 at present), but these are very rare, and currently routine testing is not available. Those with a faulty C9orf72 gene more commonly have family members with dementia (FTD).
Many of these diseases are genetic. Sometimes the cause is a medical condition such as alcoholism, a tumor, or a stroke. Other causes may include toxins, chemicals, and viruses. Sometimes the cause is unknown.
These include the Aβ precursor protein (APP) on chromosome 21 (15), presenilin 1 (PSEN1) on chromosome 14 (16), and presenilin 2 (PSEN2) on chromosome 1 (17, 18). The most frequently mutated gene, PSEN1, accounts for the majority of AD cases with onset prior to age 50.
Degenerative diseases have multiple causes and risk factors that can vary depending on the specific type of disease. However, the main causes and risk factors associated are: Genetic Factors: Presence of variants in specific genes, positive family history, and epigenetic modifications.
Hereditary neurodegenerative disorders are genetically heterogeneous. A rare inherited disease with a distinct phenotype may be caused by mutations in one specific gene only. There are neurodegenerative phenotypes where currently only one gene is known to explain the condition.
Some people have two APOE e4 genes, one from each parent. Having two genes increases the risk of getting Alzheimer's disease even more, about eight- to twelvefold. But not everyone who has one or even two APOE e4 genes gets Alzheimer's disease. And many people who don't have an APOE e4 gene get the disease.
“Lewy body dementia is a devastating brain disorder for which we have no effective treatments. Patients often appear to suffer the worst of both Alzheimer's and Parkinson's diseases.
These include mutations in the β-amyloid (Aβ) precursor protein, causing Alzheimer disease (AD); in α-synuclein, causing Parkinson disease (PD); or in microtubule-associated protein tau, causing frontotemporal dementia (FTD) with parkinsonism.
Some of the more common symptoms of neurodegenerative disorders may include: A loss of inhibition. Anxiety. Agitation. Apathy. Difficulty with movement. Forgetfulness. Memory loss. Mood changes.
Neurodegenerative diseases affect millions of people worldwide. Alzheimer's disease and Parkinson's disease are the most common neurodegenerative diseases. In the United States, as many as 6.2 million people may have Alzheimer's disease, ing to a report from the Alzheimer's Disease Association in 2022.