The genetics behind the most common hereditary diseases

Most common hereditary diseases and genetics: main cases

The most common hereditary diseases have a genetic origin, either due to chromosomal alterations or mutations in a DNA segment. Knowing each case is important; first, to check the chances of inheriting it, and second, to look for alternatives. Let's look at different cases:

1. Most common hereditary diseases: cystic fibrosis

The cystic fibrosis It is one of the most directly related hereditary diseases. It can be diagnosed at a very early age, and some symptoms include excess mucus and respiratory and digestive difficulties. The reason is in the CFTR gene mutation , which is autosomal recessive. This means that both parents must have the mutation to transmit the disease.

2. Huntington's disease

The Huntington's disease It is another of the most common hereditary cases. Essentially, it is a condition that affects the central nervous system and causes numerous involuntary movements in the sufferer. It is also autosomal dominant in nature, since it is sufficient for one of the parents to have the genetic modification by repetition on chromosome 4 .

3. Down syndrome

He Down syndrome , in most cases, is not a hereditary disease, as factors such as aging during pregnancy play a major role. It causes a certain cognitive delay and certain side effects. However, there are some cases in which it is, when one of the parents has it, due to translocation. Here we have to talk, specifically, about a trisomy of chromosome 21 .

4. Hemophilia

The hemophilia It is one of the most common hereditary disorders. The most common problem is a lack of blood clotting, which causes bruising and increased risk of minor injuries. This disease is passed from one parent to the other and is caused by deficiencies and mutations in the F8 (hemophilia A) and F9 (hemophilia B) genes . It is transmitted to men, while women can suffer from the genetic mutation but not develop symptoms.

5. Familial hypercholesterolemia

The familial hypercholesterolemia It is another of the common disorders, which is different from acquired hypercholesterolemia. Here there is a hereditary factor, of the autosomal dominant type, so that it is enough for there to be a genetic alteration in one parent. Specifically, this occurs in the PCSK9 gene .

6. Muscular dystrophy (DMD)

The Duchenne muscular dystrophy It is a disease with a significant genetic burden. Since dystrophin is not generated, what happens is that there is an increasingly pronounced muscular atrophy. In fact, it occurs as a result of a mutation in it DMD gene (Xp21 locus) on the X chromosome that primarily affects males. It is autosomal recessive, so both parents must have it for it to be transmitted.

7. Wilson's disease

The Wilson's disease It is due to an accumulation of copper in the liver and other viscera, which obviously has a highly dangerous long-term toxic potential. It should be noted that the symptoms are varied and that this condition is usually diagnosed in childhood and youth (5 to 35 years, the age of diagnosis). The abnormal accumulation of copper is due to a A mutation in the ATP7B gene , which causes it to not function normally. It is an autosomal recessive disease.

8. Thalassemia

The thalassemia It is a congenital disorder that can be diagnosed before the age of 2. It essentially consists of a significant anemia which requires blood transfusions and frequent treatment. This is caused by a mutation in one or more genes of the alpha globin protein, which regulates hemoglobin.

9. Tay-Sachs disease

A hereditary disease is called Tay-Sachs disease . What happens here is that there is a mutation in the HEXA gene It causes a deficiency in the enzyme hexosaminidase and is degenerative in both mobility and cognitive abilities. It is also autosomal recessive, so both parents must have the mutation for it to manifest.

10. Turner syndrome

He Turner syndrome It is another hereditary disease. In this case, there is a difficulty in growth, which manifests itself in various ways, including female sterility. The disease manifests at an early age, but can even be diagnosed during pregnancy. The cause is a total or partial absence of the X chromosome. It only occurs in women and, in fact, is the only monosomy that allows one to live, although with a low life expectancy .

What alternatives exist for diagnosing hereditary diseases?

The most common hereditary diseases can be diagnose Using various techniques. But common sense also applies: if a person suffers from a hereditary disease, the chances of transmitting it to their offspring are high. Here are some of the techniques:

• Genetic compatibility test: Genetic compatibility tests allow two parents to determine if they are compatible and if there is a risk of transmitting any diseases. This is always recommended, but even more so if there is a history of hereditary diseases, consanguinity, or belonging to an endogamous group.
• Prenatal test: There are prenatal tests that can be used to determine, using amniotic fluid or the mother's blood, whether there is a genetic disease. Their main disadvantage is that they are invasive, but they are useful for clarifying any doubts.
• Heel Prick Test: The heel prick test, which uses a small incision to take a blood sample, is performed on newborns. Its purpose is to detect genetic diseases early.
• Genetic test: If symptoms are compatible with a congenital disease, a test can be performed to confirm or rule out the possibility. Some conditions only manifest symptoms well into childhood or adolescence. Therefore, this is an alternative diagnostic option.

In short, there are several ways to plan ahead. And there's no doubt that knowing the odds before pregnancy can influence family planning.

In conclusion…

The most common hereditary diseases are several, but it is important to determine whether or not there is always a genetic origin. Genotics You'll find numerous genetic tests to detect, determine probabilities, or rule out. Check out all the available options!