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Autosomal disease test: what a DNA test will show and why it is important even before symptoms appear
What are autosomal diseases?
Autosomal diseases are hereditary disorders, caused by mutations in genes located on non-sex (autosomal) chromosomes. There are 22 pairs of autosomes in the human genome. If one or both copies of a particular gene have an error, disorders may occur that manifest immediately after birth or even in adulthood.
There are two main types of autosomal inheritance:
Autosomal dominant: one defective copy of a gene is enough to cause a disease (e.g. Huntington's chorea, Marfan syndrome)
Autosomal recessive: a person must carry two copies of a mutated gene for the disease to manifest (e.g., cystic fibrosis, spinal muscular atrophy, phenylketonuria)
Why is a test for autosomal diseases performed?
This test not only allows you to confirm the diagnosis, but also:
reveal carriage in a clinically healthy person
to evaluate risk of transmitting the disease to children
to carry out prenatal diagnosis or embryo testing during IVF
build surveillance or treatment strategy
This test is especially important for families where there is cases of rare diseases, for young couples before pregnancy and for patients with unexplained symptoms not explained by the classic clinic.
What diseases can be detected?
Depending on the size of the panel, you can explore from 5 to over 400 genetic diseases. The most famous:
Autosomal recessive:
Cystic fibrosis (CFTR)
Spinal muscular atrophy (SMN1)
Phenylketonuria (PAH)
Thalassemias (HBB, HBA1/HBA2)
Hemochromatosis (HFE)
Glycogenosis, organic acidemias
Autosomal dominant:
Marfan syndrome (FBN1)
Huntington's disease (HTT)
Polycystic kidney disease (PKD1, PKD2)
Li-Fraumeni syndrome (TP53)
Secondary breast cancer (BRCA1/2 – can also be dominant)
How is the testing done?
Biomaterial collection – most often venous blood is used, less often – a swab from the mucous membrane of the cheek or saliva
DNA isolation – in the laboratory, genetic material is prepared for analysis
Mutation analysis – PCR, MLPA, NGS (next generation sequencing) methods are used
Interpretation of the result – the geneticist classifies the found mutation variants according to international standards
What the results mean
Pathogenic (pathogenic mutation) – confirmed disease or carrier status
Likely pathogenic – mutation with high probability causes disease
VUS (variant of undetermined significance) – a mutation whose function is not yet known
Benign (benign variant) – genetic features that are not associated with pathology
Interpretation of results is always performed in combination with clinical presentation and family history.
In what cases is the test result life-changing?
A couple learns that they both carry the same mutation – have a 25% risk of giving birth to a child with the disease
The patient has tested positive for a late-onset disease – can start monitoring and prevention
There is a lethal mutation in the family – other members can be screened for carrier status
A mutation was detected in the fetus during pregnancy. – parents can make an informed decision
Advantages of modern testing
Non-invasiveness – a drop of blood or a smear is enough
High accuracy – the sensitivity of NGS methods reaches 99%
Possibility of prevention – knowledge of mutations allows you to take measures before symptoms begin
Planning for healthy offspring – thanks to PGT (preimplantation genetic diagnosis) in IVF
Limitations and importance of consultation
Not all options can be detected – especially if they are rare or new
Results don't always mean disease – many mutations require observation rather than treatment
Carrier status is not a diagnosis, but important information for family planning
Genetic tests for autosomal diseases are not predictions of the future, but tools for managing it. Knowledge is a chance to be prepared, protect the child, explain the symptom, avoid diagnostic errors, and not act blindly.
