Down's syndrome - a genetic abnormality, which is due to the tripling of the 21st chromosome. If a person has normal 23 pairs, or 46 chromosomes is observed treble 21st chromosome in Down syndrome instead of the two.
For the first time the disease was described by doctor John Downey in 1866 and so named for the author.
Down syndrome - quite a common condition, it is observed in one child born among 700-800. It is impossible to say who is more likely to suffer from this genetic anomaly: boys or girls, the percentage of sick children is the same as in that, and in other cases.
Typical manifestations of Down syndrome is a lag in mental and physical development (especially low rise).
Kinds
There are three forms of chromosomal abnormalities in Down syndrome:
- trisomy - occurs in 90% of cases. Trisomy - is the presence of extra 21st chromosome instead of the two of the three. What happens in case of violation of cell division in the development of the egg or sperm. A similar phenomenon is observed in all human cells;
- mosaicism - only some of the cells have an extra 21st chromosome, it looks like a mosaic of normal and abnormal cells. This defect is associated with impaired cell division after conception. The incidence is 2-3%;
- Translocation - rearrangement of the chromosome in the 21st pair. That is, there are only two chromosomes, as it should be, but only a portion of one chromosome in the 21st pair is attached to the other (extra shoulder). diagnosing rate is 4%.
Causes
To date, only two found the cause of Down syndrome.
First - this is the mother's age, and the older a woman gets, the higher the risk of a given pathology childbirth (after 30 years it is 1: 1000, and after 42 years - 1:60). This is due to the aging of oocytes: as is known, their number is established even during the formation of the fetus.
Another, rarer cause is heredity (Down syndrome type translocation 21st chromosome pair). It is understandable that a certain importance and closely related marriages, as well as the presence of a family relative with Down syndrome. In addition, the researchers noted a link between age grandmother in which she gave birth to a daughter, and a chance to get a grandchild with Down syndrome. The older was a grandmother, the higher the risk of the birth of his grandson with this anomaly. It does not deny the value of his father's age (risk factor - men older than 45 years).
Diagnosis of risk of Down syndrome
Diagnosis of Down syndrome spend more during pregnancy, at the stage of gestation.
An important indication is the woman's age (30 years and older). In the first trimester of conduct fetal ultrasound (10-14 weeks gestation) for determining the width of the neck-nuchal (norm 2 mm) and the presence / absence of the nasal bone. These symptoms are not typical, and do not give a 100% guarantee of the disease. Then carried out a blood test for levels of hCG.
In the second trimester, at time 16-18 weeks triple test performed: determination of hCG, alpha-fetoprotein (AFP) and estriol. When the decline in a woman will wear high-risk and recommend invasive examination methods:
- horiontsentez (chorionic villus sampling at time of around 13 weeks);
- amniocentesis (Analysis of amniotic fluid after 18 weeks at high risk survey abortion and infection);
- cordocentesis (Analysis of fetal cord blood, performed after 18 weeks).
After giving birth, diagnosis is based on characteristic clinical features and the determination of the karyotype.
Symptoms in newborns
Down syndrome is suspected the doctor can immediately after the birth of a child on the basis of characteristic features. However, accurate diagnosis is made after the determination of the karyotype (chromosomes).
"Daunyata", for the most part, have a flat face with Mongoloid shaped eyes and a skull shortened round shape (brachycephaly). In front noted presence vertical skinfold, which covers the inner corner of the eye (epicanthus).
There is increased joint mobility and muscular hypotonia, through which the child's mouth slightly open and tongue extended.
Nape children flattened, short neck with the head of the small size and vertically set ears with lobes firmly attached, there are dental anomalies.
At the age of 8 years often develop eye diseases (cataract, glaucoma). Bridge of the nose at the "Down" is also flattened, often it takes place strabismus and a short nose.
On the palm has a transverse crease and pinky shortened and skrivlen.
Often these children are identified congenital heart disease and digestive tract, symptomatic epilepsy and chest deformity.
Sick children can reach average height, but often their physical development is lagging behind because of violations skeletal development.
All patients with this disease is marked mental retardation in varying degrees.
Down's Syndrome Treatment
Down Syndrome Treatment for life, it is not in getting rid of chromosomal pathology, and treatment of opportunistic diseases and malformations. For example, the operation is performed in congenital heart defects.
In the treatment of "Down" involved a group of different medical specialists: a pediatrician, a psychiatrist and a psychologist, cardiologist, gastroenterologist, endocrinologist, a speech therapist, optometrist, dentist and others.
Parents of children with Down syndrome need to understand and know that this anomaly - it is not a sentence, and, moreover, one's fault in the birth of this child is not.
The main treatment is aimed at the social and family adaptation. With careful care and patience, children learn simple human skills (sit, walk, talk). They can walk in the secondary, and special schools (preferably both). In a normal school child learns to communicate with other children, develops and seeks to imitate classmates. Subsequently, these children can receive vocational education. Important in the care of a special child - is the attention and love of parents.
In order to support the central nervous "daunyatam" system prescribe drugs that improve brain circulation:
- cerebrolysin;
- piracetam;
- B vitamins;
- aminolone.
Complications and prognosis
Complications of Down syndrome include:
- congenital heart disease;
- infectious diseases;
- leukemia;
- Early dementia (Alzheimer's disease);
- cessation of breathing during sleep;
- obesity.
The life expectancy of people with this disorder is low, about 49-50 years, but in recent years it has increased: even in the twentieth century, these patients lived about 25 years. They are able to create a family, but men can not have children. As a rule, people with Down syndrome receive secondary education and employment.