Molecular Aspects Of Down Syndrome

Molecular aspects of Down Syndrome

Down syndrome is a genetic alteration produced in the pair of chromosomes 21, in which an extra copy of the chromosome is presented.

There are multiple therapies that have facilitated the development of psycho-motor skills in people with Down syndrome, therapies are the treatments of diseases whether physical or psychological.

The objective of this monograph is to determine that Down’s syndrome is its causes, symptoms and its methods of treatments in order to improve the quality of life, taking into account the development of each child.

There are many people in the world, but not all have the same genetic characteristics. Appointed in honor of John Langdon Down, the first doctor to identify the syndrome, the SD (Down Syndrome) is the most frequent genetic cause of mild to moderate mental retardation and associated medical problems and occurs in one of every 800 living births, inAll breeds and economic groups. Down syndrome is a chromosomal disorder caused by an error in cell division that results in the presence of an additional third chromosome 21 or ‘trisomy 21’.

Multiple studies show that therapies improve the cognitive and motor development of people who present Down syndrome, currently we can show different therapies, which allow social inclusion and progress their skills. In recent years, people suffering from this trisomy have a higher quality of life due to technological advances that have allowed to improve health care.

Goal

Know the therapies that exist for the development of psycho-motor skills of people with Down syndrome and thus improve their quality of life and inclusion in society.

What is Down syndrome?

To better understand, we must know how our body and cells work. The human being composed of cells, each with chromosomes, being the genetic base.;Of the 46 chromosomes, half inherited from man. Men and women contain 23 individual chromosomes, experts name them as par xx in females and par xy in males, listing them from 1 to 23.

At the time of fertilization in the woman’s ovule there are the 23 missing chromosomes, and thus the 46 chromosomes are completed. In the case of being female, it contains the 23 and the XX par, and being male contains the 23 and the XY pair, but not this happens in all cases, when there is one more element in the chromosome 21,Down syndrome occurs.

Down syndrome is also known as trisomy 21, its name is given since a genetic alteration occurs in pair 21, this is mainly characterized by the mental retardation that certain physical characteristics are associated. People who suffer from Down Syndrome have a set of diverse conditions from the cognitive area to the health area.

Down syndrome was discovered in 1866 by the Doc. John Langdon Down who is attributed his name. In 1965 it was discovered that the people carrying the syndrome possessed a genetic alteration where in pair 21, this research was carried out by the DR. Jerome Lejeune.

The excess material produces the imbalance in different biological systems and is because each chromosome is linked to the development of the organs.

Molecular aspects of Down Syndrome 

Chromosome 21 contains around 225 genes. Some of them are considered, located in the so -called Critical Region for the SD, contribute to the pathogenesis of the syndrome. Various studies have been carried out that have allowed to bring an area of 1.6 megabaases (MB) on the long arm (q) of chromosome 21, in band 22 (21q22), which, if it is in triplicate and determines certain features that characterize the SD. (Arch Argent Pediatr, 2008)

SD characteristics

Each person has their own personality influences their feelings, their environment and their family, no patient with SD is the same, all are differentiated by their essence.

Physical characteristics

Phenotypically, SD carriers suffer from very characteristic features.

• Expensive:

They have almond -shaped eyes, their nose is very small with the nasal root flat, their eyes have a mottled pigment in case of being blue, their ears are small does not have a lobe and have a very folded Hélix. His mouth is small and manifests a lingual protusion.

• Head and neck:

They have a small microcephaly and their occipital is appealing. Its neck is short, to the third trimester of pregnancy a nucral fold test is performed to see the liquid, if the liquid is excess an alteration in the chromosomes 21 can be presented. (SD)

• Hands and feet:

His hands are very small and square with metacarpals and short phalanges. Presents a cleft in the first and second finger of the feet.

• Genitals:

In children the size of the penis is small and the testicular volume is less than the population average.

Cognitive characteristics

The excess of a chromosome affects the nervous system because there is a diffuse lesion, which harms the analysis skills and even brings speech problems.

In SD there is a limitation in transmission and communication in many of the neural systems. The deficiencies of the dendritic ramifications, the early reduction of the neurons responsible for associative behavior and communication in the areas of the brain among themselves are increasingly known (María de Fátima Caldeira; Andréia Cristina Dos Santos, 2006).

People with SD have a lower brain development, this causes auditory problems, the first years of life the person suffering from the syndrome can listen normally, but as time goes by their hearing system is atrophy. Memory loss is also very common.

Types of Down Syndrome 

Trisotomy of the pair 21

Also called regular or free trisomy by the most common. In 95% of the time, in the pair of chromosomes 21 an error occurs when it does not separate as it should be, then one of the gametes (sperm or ovule) will have 24 instead of 23 chromosomes.

Different studies point out that the extra chromosome comes from the mother’s ovule, this being the most frequent cause with 92% of cases,

There is more likely that trisomy occurs in pregnancies of women over 35 years.

Translocation 

Translocation means that a part of a chromosome is linked to one part or all other chromosome. It occurs in 5% of cases, it is the rearrangement of chromosomal material, when in the process of meiosis, a chromosome 21 joins 14, 15 or 22. It is considered a risk in the distribution of the family breast that already has a child with this syndrome.

Mosaic

It occurs when the zygote is formed, when the cells were divided, at the time of fertilization where the ovule with the sperm binds. It can be given that the DNA does not separate properly, so there will be a mixture of cells and some cell will have 47 chromosomes, including three chromosomes 21.

Diagnostic tests

Down syndrome could be detected before and after birth.

Prenatal diagnosis

• During pregnancy different tests are performed, in week 10 and 14 routine ultrasounds are executed. In ultrasounds, the thickening of the nucral fold is observed and if this is greater than 8mm, it could be Down’s syndrome.
• Amniocentesis is performed by means of a small extraction of the amniotic fluid that surrounds the sack of the fetus in the womb. It implies less risk of spontaneous abortion.
• Chorionic villus sampling (CVS) is carried out between week 10 or 12 of pregnancy. This test is performed on mothers suffering from chromosomal anomalies, which can be identified by means of the placenta’s tissue. The procedure consists of the introduction of a tube, called catheter, in the cervix by means of the vagina. After obtaining the tissue sample, it is taken to a genetic laboratory to analyze the cultivation of cells. The risk of spontaneous abortion is 1-2%
• This is the most concise method, the pubs, percutaneous umbilical blood sampling, consists of removing a blood sample from the umbilical cord or the blood vessels of fetus;It cannot be done until week 18 or 20. Then he takes a laboratory for subsequent studies. In this test the risk of spontaneous abortion is greater.

Postnatal diagnosis 

When the syndrome has not been detected in pregnancy, several diagnostic tests are performed, the doctor who attends the delivery must perform them despite the fact that their phenotypic features show the characteristics of the SD.

Chromosomal tests are performed, to detect anomaly at pair 21.

Symptom evaluation 

The phenotypic characteristics of SD may not be very evident in the immediate neonatal period. At this time the great hypotonia and the characteristic, acute and choppy crying, can be the key to the diagnosis. Soon the characteristic phenotype is defined, although each one will have their own peculiarities (Mercé Artigas López).

Tests are performed to evaluate the patient’s intellectual level, these tests must have the necessary skills to evaluate the conditions of the person suffering from this syndrome.

Treatments

Down syndrome has no cure, but different treatments are performed to improve the quality of life of the person who manifests it.

Throughout his life he must have medical care, especially in his first years of life, he must receive the same care of a newborn, but if he develops digestive problems or other disorders, he must have constant medical review. They are 10 to 15 times more vulnerable to suffer from leukemia, a mortal disease.

Children with Down syndrome have learning difficulties, so they require more attention and patience when teaching them something;Because its intellectual coefficient is between 30-80, and that of a normal person is 80-120.

They have a delay in development, for this reason, they do everything slower, such as sitting, turning or even finding attention to information or processing.

Pscio-Motor Therapies

In the first months of child life with SD it is essential that therapies be carried out to help their motor and cognitive development. Early stimulation has a great benefit for the length of a child’s life. Different types of therapies can be used throughout life to enhance development, coexistence and independence as possible in your life.

There are different therapies such as:

• Physiotherapy

In the physiotherapy, activities that allow the development of motor skills and increase their muscle strength participate, it allows to improve posture and balance.

Physiotherapists help children with SD compensate for their physical limitations, so that they prevent problems for a lifetime.

One of the benefits of this therapy is that children can carry out their activities with without a great delay to the average of children, such as crawling, turning face down.

• Speech therapy 

Language therapies are performed in a playful and dynamic way that allow improving the way of communicating people with SDs.

Children with Down syndrome usually learn to speak later. Language therapy allows you to develop more premature communication skills.

One of the main methods is the use of images, the imitation of sounds, the language in signs, the correct pronunciation, understand what reads and learning allowing you to remember words.

• Classical dance 

Classical dance contributes to the well -being of a person through integration. Several studies have been carried out that indicate that people who practice classical dance have superior self – esteem after a dance class that before starting it;It is also proven that with the practice of dance over time, self – esteem continues to increase or maintain, and that these results are not linked to the sex of the subjects. (MªPilar Muñoz Morales, 2017).

The dance is very complex which allows to reorganize the nervous system in which a lotproviding a development and allows you to set goals.

Classical dance also allows you to improve your motor skills, improving the strength of the muscles and allowing faster movements. Dance classes for children with SD will be based on their skills and their degree of complexity will be increased as their dance level progresses.

Children with Down syndrome can develop their entire learning potential and follow the same development steps as the rest of the children, only that they will do it more slowly. They will depend fundamentally on a solid family that gives them love and belonging and support professionals who first create in them as ‘people’ and then as ‘people with Down Syndrome’ (Down Down, 2007).

• EQUINOTHERAPY

Equine Therapy is an alternative treatment that uses the rhythmic movement of the horse and the junión created for the treatment of people with psychomotor conditions

The horse movements in the sagittal, transverse and frontal planes stimulate the development of the cochlear lobby system and the strengthening of the muscles and joints of the rider, through the dissociation of the pelvic and scapular waist, improving its posture and tone, increasing theneuromotora coordination and space -time orientation, attention and concentration. (Miguel Amaranta, Dolores de Miguel, David Lucena-Antón, M. Dolores Rubio, 2018).

Hypotherapy is for patients with greater motor disabilities, to develop the patient’s link with SD and the first horse.

According to a study made by physiotherapists, it must be achieved that the patient with SD can develop the following:

• The patient mounts without albardón and will adapt passively to the movement of the horse without doing any action on his part, taking advantage of body heat, rhythmic impulses of three -dimensional locomotion of the horse.
• Improve your stability and stimulate to a greater extent the normalization of muscle tone, balance, psychomotor coordination and body symmetry and exercises increase neuronal synapses and cerebral plasticity. (María Candelaria).

Conclusions

In conclusion, we can see that Down Syndrome is a chromosomal disorder related to intellectual disability, a distinctive facial appearance, with a small nose and an upward inclination of the eyes, and low muscle tone in childhood. The degree of intellectual disability varies from mild to moderate. Down syndrome is caused by having three copies of chromosome 21 (called Trisomy 21) instead of the two usual copies and, usually, it is not inherited. The treatment focuses on the specific symptoms of each person.

Therapies are very important in the child’s life, people with Down syndrome develop different skills that allow him to raise his self – esteem and have a better quality of life through them and early stimulation.

recommendations

1. People with this syndrome should not be excluded from society because they are different from ‘normal’ people. They are talented and have developed their skills and abilities.
2. It is very important that the woman during her pregnancy regularly goes to the doctor and has control, because during this stage she can detect if the fetus she has has a congenital malignant neoplasia and can act on time.
3. Perform therapies to improve the psycho-motor skills of children with Down syndrome, to obtain a better quality of life