Congenital, genetic and hereditary diseases: do you know the difference between them? – 08/23/2021

In the middle of the word “congenital” there is a “gen” that can refer us to the word “genetic”, which for many is synonymous with something “hereditary”. In common, they are related to nature and human conception, which is why they generate so much confusion. But although they seem to be the same thing, diseases classified with these terms are not the same, the differences between them are great.

Of course, it is not up to anyone who has not studied medicine to diagnose each one, this is a doctor’s task, but it is worth knowing what they individually represent to have information to talk to, to gain time to ask questions in the office, to prepare for exam results, plan a possible pregnancy, take preventive measures and change lifestyle habits.

Congenital, or from birth

A congenital disease is one that is present at birth, which may be due to a change in genes and passed on from parents to children or also caused by external environmental factors, such as infections, drug use, medications or some interference in the uterus, by example.

Pablo de Nicola, geneticist from Unifesp (Federal University of São Paulo) and from BP – The Beneficência Portuguesa of São Paulo, cites examples: “The most common congenital disorders (from birth) are congenital clubfoot, congenital hip dislocation, cryptorchidism (when the testicle does not descend), congenital heart disease (cardiac defects), myelomeningocele (defect in which the baby’s spinal cord does not develop properly) and hydrocephalus (characterized by the abnormal accumulation of fluid within the skull, leading to swelling and increased pressure brain)”.

But there are others, such as cleft lip and palate, congenital toxoplasmosis, fetal alcohol syndrome, tetralogy of Fallot (a rare condition caused by a combination of four heart defects present at birth), and Down syndrome.

But not every disease passed on from parents to children and/or caused by changes in genes is congenital, and may manifest later as Huntington’s Chorea (in which nerve cells in the brain break down over time) and Alzheimer’s.

Genetics is about DNA

Genetic, Hereditary, Congenital Disease 2 - iStock - iStock
Image: iStock

A disease or genetic disorder, on the other hand, is caused by one or more anomalies in the genetic material (DNA) for various causes (poor diet, solar radiation, smoking, among others) and may or may not be transmitted onwards, from ancestors to descendants.

When it comes to cancer, every type is genetic, but that doesn’t mean it can be inherited. Renata Velame, oncologist and oncogeneticist at Hospital Português da Bahia, in Salvador, explains:

Cancer is a genetic disease, as it involves mutations in certain parts of the DNA, leading cells to an uncontrolled process of multiplication, in addition to the ability to invade other organs and tissues in the body. In most cases, it is sporadic, that is, these mutations are acquired throughout life due to environmental factors. But some cases of cancer, about 5% to 10%, develop due to pathogenic genetic mutations inherited, mostly from one of the parents, what we call hereditary cancer syndromes.”

In these cases, the appearance of tumors is generally seen earlier, there is a greater risk of new tumors throughout life, and a family history of cancer is commonly observed.

The main types of neoplasms associated with these syndromes are breast, ovarian, prostate and colorectal cancers. But it does not mean 100% that a person with a pathogenic mutation will have cancer, there is a risk, but several other factors are involved in its formation.

Hereditary are transmitted

Introduced briefly in the explanation of genetic diseases, hereditary diseases are those that can be inherited from one or both parents and passed on to offspring. Thus, not all genetic diseases are hereditary, but all hereditary diseases are genetic and can manifest themselves from birth, or not, only over the years.

“As hereditary conditions that, once again, increase the chance of developing cancer, are Li-Fraumeni syndromes (characterized by multiple cases of early-onset primary tumors), Peutz-Jegher syndrome (multiple hamartomatous polyps appear in the stomach, intestine slender and neck) and Cowden (multiple lesions appear on the skin, breasts and brain)”, informs Mariana Marcondes MS Pereira, doctor at the Santa Casa de Misericórdia in Santos (SP) and oncologist at the Clinonco clinic and at the Dr. Mario Gatti Municipal Hospital , in Campinas (SP).

In addition to conditions that predispose cancer, sickle cell anemia (a condition that causes anatomical changes in red blood cells), cystic fibrosis (affects lungs and digestive system), familial hypercholesterolemia (aggressive and premature cardiovascular disease) also enter the list, which would not fit here. ), osteogenesis imperfecta (impairs the correct formation of bones), hemophilia (compromises the formation of blood clots) and color blindness (difficulty in differentiating certain colors).