What is Down syndrome?

Down syndrome is a genetic alteration produced by the presence of 3 chromosomes 21, when the normal thing is that there are two. It is the main cause of intellectual disability and the most frequent genetic alteration. It affects 1 in every 700 pregnancies. It is more frequent when the mother is over 35 years of age. Pregnant women undergo specific tests during the first trimester of pregnancy to detect the risk of having a child with Down syndrome.

All human cells have 46 chromosomes arranged in 23 pairs. One of these pairs determines the sex of the individual and the other 22 are called autosomes, numbered from 1 to 22. The egg and the sperm each contain only 23 chromosomes (one chromosome from each of the 23 pairs), in such a way that when they join they produce a new cell with the same genetic load as any other human cell, that is, 46 chromosomes divided into 23 pairs. It is during this process that most of the alterations that give rise to Down syndrome occur.

exist three types of chromosomal abnormalities that can cause Down syndrome:

• Trisomy 21: it is the most frequent type and is characterized by the presence of three chromosomes 21.
• Chromosomal translocation: it is very rare. An extra chunk of chromosome 21 joins the chromosome 14 pair.
• Mosaicism: in the same individual there are cells with trisomy 21 and others are normal.

How is Down Syndrome diagnosed?

Diagnosis can be made before delivery or after delivery. When the child is born, the diagnosis is suspected by physical examination and phenotype (by facial features and physical characteristics), but (karyotype).

Diagnostic tests before delivery are recommended in women over 35 years of age or if the screening tests (ultrasound and laboratory tests) give a high risk of having a child with Down syndrome. Prenatal diagnosis consists of performing a chorionic villus biopsy (in the eighth week of pregnancy) or an amniocentesis (in the 16th week of pregnancy). Both tests must be well indicated since there is a risk of miscarriage.

Symptoms

Children with Down syndrome can associate some diseases. It is important to remember that not all children with trisomy 21 have it. The more frequent alterations are:

• Congenital heart malformations
• Hearing and vision problems
• Hormonal (endocrine) problems
• Neurological disorders
• Intestinal abnormalities

All of these diseases require specific monitoring from birth, and they all have treatment.

Treatment

It is essential early diagnostic, to correctly guide families and offer the child with Down syndrome the best stimulation. It is a multidisciplinary work that tries to alleviate, as far as possible, the effects of the syndrome on the development of the child. The programs of Early attention They are essential to stimulate the child with Down syndrome at a sensory and motor level. Thanks to the proper monitoring and treatment of the medical problems of children with Down syndrome, they can have an acceptable quality of life and their average life expectancy is about 60 years.