10 most common genetic diseases

A genetic disease is caused by an abnormality in one or more genes or in an entire chromosome. It results from the transfer of a mutated gene or from a spontaneous mutation. Many times, these diseases appear in childhood and are progressive, some leading to early death. There are more than 8,000 genetic diseases that cause a wide variety of health issues depending on the function of the genes affected.

It is claimed that humans have between 20,000 and 30,000 genes. When a genetic abnormality occurs by chance in one of these genes, its protein is changed or not produced. But true protein production is necessary for the body to function.

What is the difference between DNA, genes and chromosomes?

The human body is made up of billions of cells. Cells are the basic unit of living things. It has different functions and states. The control center of the cell is the nucleus. Each nucleus of cells contains the genetic inheritance of every human being, consisting of 23 pairs, a total of 46 chromosomes. Of these pairs, 22 are common to both sexes. The remaining 2 chromosomes are the sex chromosomes. XX chromosomes for women and XY chromosomes for men.

The child inherits half of the father’s genetic inheritance (23 chromosomes) and half the mother’s genetic inheritance (23 chromosomes). 46 chromosomes are formed by a filament (cytoskeletal element): DNA (deoxyribunocleic acid). DNA forms the genome in which all the information necessary for the functioning of the organism is archived.

A gene is a DNA module with a plausible function. Humans have about 20,000 genes. No one has exactly one-to-one DNA. Therefore, there are differences in the DNA of each individual. Genetic diseases occur when one of these genetic differences leads to a change that alters the function of a protein and can cause a disease.

What is a mutation?

Mutation, which is the starting point of genetic diseases, is the change of genetic information. An ex officio mutation can occur in a variety of ways, from a change in a single letter in the genetic code to the presence of extra chromosomes.

Not all mutations result in disease.

10 most common genetic diseases

To date, approximately 8,000 genetic diseases have been identified, but some are quite rare. We have listed the prevalence, genetic origins, and symptoms of the most common genetic diseases that you hear often.

cystic fibrosis

Incidence: 1 in 4,000 to 8 thousand births.

Genetic origin: Mutation of both copies of the CFTR gene located on chromosome 7.

Symptoms: Irregularity of chlorine transport in the cells, which leads to an increase in the fluidity of the mucus. This mucus accumulates in the respiratory and digestive tracts and causes bronchial obstruction.

Neurofibromatosis type 1 (NF1)

Incidence: 1 in 4 thousand people.

Genetic origin: Mutation of the NF1 gene located on chromosome 17.

Symptoms: Lack of production of neurofibrin, a protein that inhibits tumor formation. Neurofibromas deform along the endings, leading to a wide variety of health issues. Spots on the skin, neurological disorders, disorders in bones, internal organs and hypertension can be seen.

trisomy 21 (Down Syndrome)

Incidence: 1 in 700 to 1000 births.

Genetic origin: The 21st chromosome is found in three copies instead of two.

Symptoms: The excess of genes carried by the 21st chromosome leads to various changes. Intellectual deficiency, heart defects, hypotonicity, orthopedic and visual deficiencies may occur.

Hemophilia

Incidence: 1 in 5 thousand boys.

Genetic origin: Mutations of the F8 or F9 genes on the X chromosome. It is a recessive disease, so women are healthy carriers, but it can be seen very rarely.

Symptoms: Absence or deficiency of a clotting factor often leads to spontaneous bleeding, unusual bleeding after minor injuries, bleeding into the joints (hemarthrosis) and muscles (hematomas).

Duchenne muscular dystrophy (DMD)

Incidence: 1 in 3 thousand 300 boys.

Genetic origin: Mutation of the DMD gene located on the X chromosome. Females are healthy carriers.

Symptoms: In the absence of dystrophin, the fibers that make up the skeletal muscles, smooth muscles and cardiac muscle are damaged with each contraction. This leads to muscle weakness, frequent falls, followed by trouble breathing, palpitations, damage to digestive muscles, bone fragility.

sickle cell disease

Incidence: It is estimated that 300 thousand sick children are born annually.

Genetic origin: Mutation of the HBB gene located on chromosome 11.

Symptoms: Unusual hemoglobin is found in red blood cells that carries oxygen to the tissues. Unusual red blood cells are destroyed prematurely, which is the source of chronic anemia. In addition, the blood vessels are clogged. This disease also weakens the spleen, which affects the body’s ability to fight infections, particularly pneumonia and meningitis.

HFE hemochromatosis (type 1)

Incidence: One out of every 200 people in the Caucasian race carries the disease gene.

Genetic origin: Mutation of the HFE gene located on chromosome 6.

Symptoms: Lack of hepcidin synthesis or activity, which regulates the absorption of iron by the body. This leads to a very iron overload that causes chronic fatigue, thickening of the skin, joint pain and subsequent tissue damage. Liver damage, diabetes, hypogonadism, heart failure, and osteoporosis may occur.

Romano-Ward syndrome

Incidence: One event in 5 thousand people.

Genetic origin: Mutation of genes encoding cardiac ion channels.

Symptoms: Intermittent heart conditions, fainting spells with or without unconsciousness, and even cardiac arrest.

Huntington’s disease

Incidence: One event in 20 thousand people.

Genetic origin: An abnormality in the number of repeats of a nucleotide triplet at the end of the Huntingtin gene on chromosome 4.

Symptoms: Huntingtin deficiency leads to degeneration of neurons. The disease usually begins between the ages of 30 and 50 with the onset of motor, cognitive, and psychiatric disorders. Sudden and involuntary movements, unusual posture, muscle stiffness, language and perception disorders, depression, anxiety, finitude and apathy are seen.

XYY syndrome

Incidence: One event in 1000 boys.

Genetic origin: Additional Y chromosome in males.

Symptoms: Premature height, macrocephaly, mental retardation, autistic disorders, hyperactivity, learning difficulties.