Down syndrome is the result of a genetic alteration that occurs in about 1 in every 700 babies born. Studies still cannot state the exact reason, but indicate that the vast majority of cases are related to the advanced age of the mother. However, science points out that this extra chromosome may come from either the father or the mother at the moment of conception.

What is Down Syndrome

Down syndrome consists of an error in the process of conception and in the division and multiplication of the embryo’s cells. Every human being has 46 chromosomes where genes are located, and when this chromosomal alteration happens the individual will have 47 chromosomes, with the extra chromosome being a copy of pair 21, or trisomy 211.

Just as there is genetic variety in the population, there are types of Down syndrome that are divided into three categories:

  • Free Trisomy – The most common type of Down syndrome2, free trisomy accounts for 92% of cases in children with the condition. In this type, the extra chromosome 21 is present in all cells and results from an abnormal egg or sperm that prevents proper fusion during meiosis. During embryonic development, this additional chromosome will remain in all cells.

  • Mosaicism – This is a rarer type of syndrome3, affecting about 2 to 4% of children. Here, some cells have 46 and others have 47 chromosomes, creating variation. Studies indicate that the embryo may have been fertilized with the correct number of chromosomes, but during cell division, some cells acquired the extra chromosome 21, and the individual may have milder symptoms than usual.

  • Translocation – Also very rare4, translocation occurs in about 3 to 4% of cases. In this type, all cells carry 46 chromosomes, but a fragment may break off or move to another chromosome, either before or during conception. The individual ends up with two normal chromosome 21s and a third attached to another chromosome, resulting in the symptoms and characteristics of Down syndrome.

Down Syndrome Characteristics

Children born with Down syndrome have very specific characteristics, but these may vary from one baby to another, and every case is unique. Some may be born underweight and gradually reach an appropriate weight as they grow.

Other cases are born with muscles that are less toned than usual, which strengthen as the child grows. The skin is generally looser than normal for babies, especially in the neck and nape area.

Development

The growth of a child with Down syndrome should be monitored by a pediatrician or specialist, comparing it to the growth and development chart for children with Down syndrome.

Another very common characteristic in children with Down syndrome is the eyes, which are slanted upwards and have an extra fold in the eyelid that does not affect their vision. Their head is usually flatter and the ears tend to be set lower than usual.

They show more learning difficulties, with some cases being more pronounced than others, and it is not possible to know the degree of difficulty at birth.

These characteristics become apparent as they develop. Children with Down syndrome crawl, walk, talk, play, read and write like any other child but may take longer than average, with each developing at their own pace.

Health Problems

Regarding health problems, children with Down syndrome usually have more respiratory infections than usual, and may also have a lot of difficulty breastfeeding in the first few days of life, struggling to suck and swallow.

Another very common problem in these children is heart disease, affecting 1 in every 3 children with the syndrome. The cardiac issue can be a simple murmur, but in some cases may be more complex malformations that require surgery for correction.

Traits such as short stature, obesity, diabetes, and hypothyroidism are also commonly observed in children with Down syndrome. Today, major institutions provide support through professionals better trained to care for these children, offering better care and monitoring for their physical, mental, and motor development.

Because of this great progress, today, with the support of the government, more and more teenagers and adults with Down syndrome are being integrated into the job market, giving each of them the chance to have a dignified and respectful life as every human being should.

See also: My Birth Experience and Down Syndrome – Ana Cristina

Photo: Andrea