How genetic research helps diagnose rare diseases

How genetic research helps diagnose rare diseases

Strengthening interfamily dialogue contributes to the early diagnosis and treatment of asymptomatic family members

It is not easy to diagnose a rare, genetic, and inherited disease, and it is common for patients with a variety of rare diseases to be reluctant to ask family members to discuss it. The reasons that can lead to obstacles to honest conversation are different: people may be afraid that they will break relationships, be seen as guilty, or have a feeling that this is private information.

However, correct early diagnosis and continued appropriate treatment avoids factors that accelerate the progression of the rare condition. Going through several doctors and specialties, patients with rare diseases need on average up to seven or two years to get an accurate diagnosis of the pathology they are facing, which often complicates cases that can be avoided with proper treatment. As more than 80% of rare diseases are of genetic origin, it is necessary for people who are diagnosed to encourage their family members – even those without symptoms – to investigate whether they have also been affected.

About 13 million Brazilians suffer from rare diseases, according to a study by Interfarma, and 50% to 70% of people suffering from these diseases are children. There are currently 5,000 to 7,000 species of these diseases and these numbers continue to increase regularly as new rare diseases are often described in the medical literature.

To be considered rare, diseases are analyzed in terms of their frequency in the population. The Ministry of Health accepts as a rare disease any condition with a frequency equal to or less than 65/100 thousand, or 1.3 patients per 2,000.

Monitoring the disease in the family is an important attitude because, even with diseases of recessive genetic inheritance, parents, uncles and grandparents generally live normally and have no idea that they have a tendency to give birth to children with rare diseases to this day. someone is born with a rare disease in the family. When relatives also have the opportunity to be tested for the disease, the possibility of diagnosing and treating asymptomatic family members opens up before serious conditions develop.

Discover some rare diseases:

Multiple sclerosis

It is a neurological, chronic, progressive and autoimmune disease. It is usually diagnosed in patients between the ages of 20 and 40, affects the brain, eyes and spinal cord – and does not cause dementia. In multiple sclerosis, the immune system mistakenly considers healthy cells in the protective sheath of nerves to be “attacking cells” and begins to attack them, eroding and damaging the myelin sheath.[v].

Pompe disease

It is a degenerative, progressive and inherited genetic neuromuscular disease that affects patients of all ages. Lack of enzymes creates a gradual accumulation of glycogen in muscle cells and, consequently, a person has muscle weakness, difficulty breathing and other symptoms that are confused with other common diseases.

Gaucher disease

People with Gaucher disease can see that their symptoms appear at any point in their lives. However, most cases occur until adolescence. Diagnosis can take up to 10 years, and about 25% of patients do not have access to adequate treatment due to late diagnosis.

Fabry’s disease

Fabry disease, a rare, progressive and multisystem hereditary genetic disease. Symptoms of Fabry’s disease include diarrhea, nausea, vomiting, abdominal pain, small red spots on the skin, intolerance to cold and / or heat, decreased sweating, proteinuria and others. As the disease progresses, the risk of developing fatal complications such as end-stage kidney disease, stroke, heart fibrosis, arrhythmia, and even death increases.


Symptoms and signs such as short stature, joint contractures, corneal opacity, enlarged tongue, spleen and liver usually occur in early childhood. Due to various symptoms, it is difficult to diagnose MPS and many patients go through more than 10 medical consultations before being referred to a real specialist.


It is a rare blood disorder that causes clots to form in small blood vessels throughout the body. These tiny clots can block flow to major organs, such as the kidneys, brain or heart.


Acid sphingomyelinase (ASMD) deficiency is a rare and potentially fatal genetic condition historically known as Niemann-Pick type A, B, or A / B disease. It is estimated that 1 in 200,000 people worldwide is born with a gene that causes the disease. Due to this rarity and lack of knowledge on this topic, ASMD may not be detected in the early stages, which implies disease progression and, ultimately, patient death, even before diagnosis – mostly type A, is considered the most serious.

Source: Compass – Exam

Leave a Comment

Your email address will not be published.