Early onset familial Alzheimer’s disease – Diagnostics – Overview of Information and Clinical Research

Early onset familial Alzheimer’s disease is a rare form of Alzheimer’s that appears before age 65, sometimes as early as the 30s or 40s. Unlike the more common late-onset form, this type is often caused by specific genetic mutations passed down through families. Getting the right diagnosis can be challenging, as healthcare providers may not initially look for Alzheimer’s in younger people, but understanding the diagnostic process can help you or your loved one get the care and support needed.

Introduction: Who Should Seek Diagnosis

Early onset familial Alzheimer’s disease, also called EOFAD, is diagnosed when symptoms appear before the age of 65. This condition accounts for less than 5% of all Alzheimer’s cases, making it quite uncommon. Many people with early-onset disease first notice symptoms when they’re in their 40s or 50s, though in rare cases symptoms can begin as early as the 30s.^[1]^[2]

You should consider seeking diagnostic evaluation if you or a loved one experience memory problems that disrupt daily life, especially if you’re younger than 65. This is particularly important if there’s a family history of Alzheimer’s disease or dementia, as familial Alzheimer’s often runs in families. About 60% of early-onset cases have a positive family history, and roughly 13% are inherited in an autosomal dominant manner—meaning if a parent has the mutation, each child has a 50% chance of inheriting it.^[2]

Getting an accurate diagnosis can be especially challenging for younger people. Healthcare providers generally don’t look for Alzheimer’s disease in people under 65, which can lead to a long and frustrating process. Symptoms may be incorrectly blamed on stress, depression, or other conditions. There may be conflicting diagnoses from different healthcare professionals before the correct answer emerges.^[4]^[16]

⚠️ Important

If you’re experiencing memory problems or other cognitive changes, it’s advisable to have a comprehensive medical evaluation with a doctor who specializes in Alzheimer’s disease. Even if you or your loved ones think the changes might be due to stress or work pressure, it’s better to rule out serious conditions early. Contact your local Alzheimer’s Association or a memory disorders center for a referral to an appropriate specialist.

Early warning signs that should prompt you to seek diagnostic testing include unusual memory loss, particularly forgetting recent events and the names of people and things. You might notice difficulty concentrating or completing familiar tasks, confusion with time or place, or trouble with visual images and spatial relationships. Problems with speaking or writing, misplacing things without being able to retrace steps, decreased judgment, and withdrawal from work or social activities are also common early symptoms.^[2]

If you have a parent or grandparent who developed Alzheimer’s before age 65, your risk is higher. In families with confirmed early-onset familial Alzheimer’s disease, the condition follows a predictable inheritance pattern. This doesn’t mean you will definitely develop the disease, but it does mean diagnostic evaluation becomes more important if you notice any symptoms.^[5]

Diagnostic Methods

Diagnosing early onset familial Alzheimer’s disease involves several different types of tests and evaluations. The process is designed to confirm that Alzheimer’s is causing your symptoms and to rule out other conditions that might look similar. There’s no single test that can diagnose Alzheimer’s on its own—instead, doctors use a combination of approaches to build a complete picture.^[4]

Medical History and Physical Examination

The diagnostic process typically begins with a thorough medical history and physical examination. Your doctor will ask detailed questions about your symptoms, when they started, and how they’ve progressed over time. They’ll want to know about any family history of dementia or Alzheimer’s disease, which is particularly important in early-onset cases. The doctor will also review your complete medical history, including any other health conditions you have and medications you’re taking, as some medical problems and drugs can cause memory and thinking problems.^[4]

A physical examination helps identify or rule out other medical conditions that could be causing cognitive symptoms. For example, thyroid problems, vitamin deficiencies, infections, or side effects from medications can all cause memory and thinking difficulties. Your doctor will check your overall health, including your blood pressure, heart rate, and other vital signs.^[16]

Cognitive and Neuropsychological Testing

Cognitive tests are a key part of the diagnostic process. These tests evaluate your memory, thinking skills, problem-solving abilities, attention span, counting skills, and language abilities. They might involve answering questions, solving puzzles, remembering lists of words, or drawing simple shapes. These tests help doctors understand which aspects of thinking and memory are affected and how severely.^[4]

More detailed neuropsychological testing may be recommended. This is a comprehensive evaluation performed by a specialist that can take several hours. It assesses many different aspects of brain function in detail, including memory, reasoning, language, visual-spatial skills, and executive functions like planning and organization. These tests can detect subtle changes in thinking abilities and help distinguish Alzheimer’s from other conditions that affect the brain.^[16]

Brain Imaging

Brain imaging studies are commonly used to help diagnose Alzheimer’s disease. These tests allow doctors to see the structure and sometimes the function of your brain. They can help identify changes that occur with Alzheimer’s and rule out other causes of symptoms like strokes, tumors, or bleeding in the brain.^[4]

A computed tomography (CT) scan or magnetic resonance imaging (MRI) scan can show the structure of your brain. In people with Alzheimer’s disease, these scans might reveal shrinkage (called atrophy) in certain brain areas, particularly the hippocampus, which is important for memory. However, in early stages of the disease, the brain may look relatively normal on these scans.^[16]

More specialized imaging may be available at some medical centers. These advanced techniques can provide additional information about brain function and the presence of abnormal proteins associated with Alzheimer’s disease, though they are not routinely used for all patients.^[4]

Laboratory Tests

Blood tests and sometimes other laboratory tests are important parts of the diagnostic workup. These tests don’t diagnose Alzheimer’s directly, but they help rule out other conditions that can cause similar symptoms. Common blood tests check for thyroid problems, vitamin B12 deficiency, kidney or liver disease, and infections. Addressing these conditions, if present, might improve cognitive symptoms.^[16]

Genetic Testing

For early onset familial Alzheimer’s disease, genetic testing plays an important role. Clinical testing is available to detect mutations in the three genes most strongly associated with EOFAD: Presenilin 1 (PS1 or PSEN1) on chromosome 14, Presenilin 2 (PS2 or PSEN2) on chromosome 1, and Amyloid precursor protein (APP) on chromosome 21. A mutation in any of these genes follows an autosomal dominant inheritance pattern, meaning a person only needs one copy of the mutated gene to develop the disease.^[1]^[2]

To date, 230 mutations in these three genes have been identified. The mutations affect a common pathway in how the brain processes a protein called amyloid beta, leading to excessive production of this protein. The buildup of amyloid beta in the brain is believed to be a key factor in causing Alzheimer’s disease.^[3]

Not everyone with early-onset Alzheimer’s will have one of these genetic mutations. In fact, only about 11% of people with young-onset Alzheimer’s have a mutation in one of these three genes. Most cases of early-onset Alzheimer’s are not caused by known genetic mutations, even though they occur at a younger age.^[5]^[11]

Genetic testing also looks at other gene variants that can influence Alzheimer’s risk. The apolipoprotein E (APOE) gene is one example. This gene comes in three forms: APOE 2, APOE 3, and APOE 4. The APOE 2 form appears to decrease risk of Alzheimer’s, APOE 3 is neutral, and APOE 4 increases risk. Having one copy of APOE 4 is associated with a 3-fold increased risk for Alzheimer’s, while having two copies is associated with an 8 to 10-fold increased risk. However, it’s important to understand that APOE 4 does not cause the disease—it only influences risk. Many people with APOE 4 never develop Alzheimer’s, and many people without it do develop the disease.^[1]^[9]

⚠️ Important

Genetic testing for familial Alzheimer’s disease is a serious decision that should be made carefully with the help of genetic counseling. If you have a family history of early-onset Alzheimer’s, genetic counseling can help you understand your risk, the implications of testing, and how test results might affect you and your family members. Genetic counselors can also discuss the emotional and practical considerations of knowing your genetic status.

Distinguishing EOFAD from Other Conditions

One of the challenges in diagnosing early onset familial Alzheimer’s disease is distinguishing it from other conditions that can cause similar symptoms in younger people. Depression, stress, vitamin deficiencies, thyroid problems, and side effects from medications can all cause memory and concentration difficulties. Other types of dementia, such as frontotemporal dementia, can also occur in younger people and may initially look similar to Alzheimer’s disease.^[4]

The combination of clinical evaluation, cognitive testing, brain imaging, laboratory tests, and in some cases genetic testing helps doctors make an accurate diagnosis. This comprehensive approach ensures that other possible causes of symptoms are investigated and that the diagnosis reflects what’s truly happening in your brain.^[16]

Diagnostics for Clinical Trial Qualification

When researchers study potential treatments for early onset familial Alzheimer’s disease, they use specific diagnostic criteria to enroll participants in clinical trials. These criteria are designed to ensure that trial participants truly have the condition being studied and that the results of the trial will be meaningful and reliable.^[4]

Clinical trials typically require confirmation of the Alzheimer’s diagnosis through multiple methods. Participants usually need to have documented cognitive impairment based on standardized cognitive tests that measure memory, thinking, and other mental abilities. The specific tests and the scores required for enrollment vary depending on the trial, but commonly used assessments evaluate global cognitive function and the severity of dementia symptoms.^[16]

For trials focused specifically on familial Alzheimer’s disease, genetic testing is often a key requirement. Researchers may require participants to have a confirmed mutation in one of the three genes associated with EOFAD (PSEN1, PSEN2, or APP). This ensures that all participants in the trial have the same underlying cause of their disease, which makes it easier to determine whether an experimental treatment is effective.^[1]

Brain imaging is frequently required for clinical trial enrollment. Many trials use MRI scans to document brain structure and to ensure that participants don’t have other brain abnormalities that could affect the study results. Some trials also use advanced imaging techniques to detect the presence of amyloid plaques or other protein deposits in the brain that are characteristic of Alzheimer’s disease.^[16]

Age is an important criterion in clinical trials for early-onset Alzheimer’s. Trials may specify an age range for participants, typically focusing on people younger than 65 or sometimes younger than 60. This ensures that the study population matches the target group for whom the treatment is being developed.^[4]

Participants must usually be in a certain stage of the disease. Some trials focus on people with very early or mild symptoms, while others study those with more advanced disease. The stage of disease is typically determined using standardized assessment scales that rate the severity of cognitive impairment and the ability to perform daily activities.^[16]

Clinical trials also have exclusion criteria—conditions or factors that would prevent someone from participating. Common exclusions include other neurological conditions, severe medical illnesses, current use of certain medications, and conditions that might make it unsafe for the person to participate or that might interfere with evaluating the treatment’s effects.^[4]

If you’re interested in participating in a clinical trial for early onset familial Alzheimer’s disease, your doctor can help you find trials that might be appropriate. Organizations like the Alzheimer’s Association also offer clinical trial matching services that can connect you with studies looking for participants with your specific characteristics.^[16]

Prognosis and Survival Rate

Prognosis

Early onset familial Alzheimer’s disease is a progressive condition, meaning symptoms become more severe over time as the disease damages more of the brain. The progression can vary from person to person, but generally the disease moves through stages from mild memory problems to more severe cognitive impairment and eventually to complete dependence on caregivers for all daily activities. People with early-onset Alzheimer’s may be in any stage of dementia—early stage, middle stage, or late stage—and the disease affects each person differently.

Several factors affect how the disease progresses. The specific genetic mutation involved can influence the age of onset and the rate of progression. People with mutations in the PSEN1 gene, which is the most common cause of familial Alzheimer’s, often develop symptoms and experience progression somewhat predictably within families. Other health conditions, overall physical health, and access to care and support can also influence the course of the disease.

In the later stages of early onset familial Alzheimer’s disease, people may forget how to perform simple tasks like brushing their hair, experience mood swings, have difficulty with language, show confusion and poor judgment, experience hallucinations or seizures, and eventually require full-time care. As the disease progresses, individuals may lose the ability to communicate, recognize loved ones, and perform basic functions.

Survival Rate

People with Alzheimer’s disease typically survive 8 to 10 years after symptoms appear, though the course of the disease can range anywhere from 1 to 25 years. Survival tends to be shorter in people diagnosed after age 80 compared to those diagnosed at younger ages. For early-onset Alzheimer’s disease specifically, because it affects younger people who may be otherwise healthy, survival times can sometimes be longer than in older individuals with late-onset disease.

The eventual cause of death in Alzheimer’s disease is usually not the brain disease itself but rather complications that arise as the disease progresses. Common causes include pneumonia, malnutrition, and general body wasting. As people lose the ability to swallow properly and become immobile in late stages, they become more vulnerable to infections and other medical complications.

It’s important to note that these are general statistics and individual experiences can vary considerably. Some people progress more slowly than average, while others may decline more rapidly. Healthcare providers can offer more personalized information based on your specific situation, genetic profile, and overall health status.

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