congenital acromicria

August 12, 2017 17:51 | Genetic Diseases

peculiar form of mental retardation is described by L. Downey in 1866. The author noted a sharp decline in intelligence, combined with the typical appearance of people and a variety of developmental disabilities.The first description of Down's syndrome in Russia is done by PI Kovalevsky in 1905. Among mentally retarded children 10% of Down syndrome suffer .Both sexes are affected to about the same frequency.

When Down syndrome found a variety of malformations.The nature of defects and their distribution is significantly different from the nature and frequency of defects in the population.The analysis of deaths of children with Down syndrome showed the presence of congenital heart defects and major vessels in 67% of cases.Almost all the vices of the cardiovascular system with Down's syndrome are accompanied by defects in the development of other organs and systems.Often they are accompanied by malformations of the digestive system.With the genitourinary system include the following defects: congenital u

reter expansion, expansion or contraction of the ureter, lobulation kidney, polycystic kidney and no.In some cases, reveal the absence of light, the absence or underdevelopment of the lung lobes.A decrease in brain size, underdevelopment of the frontal lobes, sulci and gyri, often formed by a variety of abnormalities of the blood vessels of the brain.Brain ventricles are often underdeveloped, their cavity reduced.Nerve cells are not sufficiently developed.Often marked combined malformations of various organs and systems, multiple congenital malformations.

disease is usually detected at birth: the child's weight is usually below normal, the children listless, poorly suck, weak cry.Among the most common symptoms to be noted an irregular shape of the skull, slanting eyes, the crescent of skin fold in the corner of the eye (near the nose), high palate, small ears and their low position.Characterized by a disproportion of the trunk and limbs.Hands have a peculiar structure - short fingers, twisted and shortened the little finger.Often expressed transverse skin fold in the palm of your hand.Noteworthy marked reduction in muscle tone, absence of certain reflexes.Reduced muscle tone is an important feature of Down syndrome, especially in the neonatal period.Children suffering from Down's syndrome, develop a rough delayed motor and mental functions.Anomalies in the physical structure at an older age are similar and relate primarily bone.The figure of such children squat, short limbs, shoulders slumped, his head bent forward.Almost always marked brachycephalic skull shape (the predominance of the transverse dimension of the head), sloping neck, the underdevelopment of the bones of the nose and upper jaw, lower jaw protruding.Often you will notice a variety of dental anomalies.When X-ray found bone deformities of the fingers, especially the thumb V, osteoporosis and some other characteristic features.

typical sign of Down's syndrome is a decrease of intelligence.The vast majority of children are imbeciles (86%), 10% -idioty, 4% -debily.Underdevelopment of speech is seen in all people with Down syndrome.Understanding speech is also limited.Any instructions are executed poorly.The vocabulary is poor, includes the names of common usage objects, simple actions and qualities.words are pronounced correctly, is often detected gross violation of phonetics hissing and whistling sounds: use simple phrases is characteristic for the speech.Logical and grammatical aspect of speech is also quite difficult.Reading and writing are formed with difficulty, the expense is performed with difficulty.Children with Down syndrome tend to be educated in special schools.They are easily distracted, suggestible, attention and memory are significantly reduced.Mechanical memory prevails over the semantic.Abstract thinking is sharply limited.Children in some cases, teaching reading, but it is only mechanical in nature, while the semantic interpretation can not be read.

condition of the emotional sphere is characterized by a number of features that distinguish Down syndrome from other forms of dementia.Noteworthy emotional liveliness, the relative safety of emotions as compared with the depth of intellectual defect.The children are very attached to the close people, affectionate, but differ in mood instability with affective outbursts, unmotivated negativism.When Down syndrome is well-developed ability to imitate.Thanks to this feature, the children manage to instill self-service skills.

In a study of children in a hospital most often show malformations of the cardiovascular system.The frequency of heart defects with Down syndrome is 51%.The most common include detectable defects triad, tetrad and pentad Fallot, pulmonary artery hypoplasia, hypoplasia of the aorta, cleft arterial duct, defects in the atrial and ventricular septal.In many patients the disorders of the endocrine system: obesity, decreased basal metabolic rate, which appears to be associated with decreased thyroid function.

The examination neurologist detected violation of lock look with both eyes on the same subject (convergence), convergent strabismus, facial asymmetry.Often there are violations of the vestibular system, which is manifested by involuntary movement of the eyeball in the horizontal direction, sometimes with elements of circular motion.Most children with Down syndrome have mild incoordination, blurred when the coordination of samples (for example, when you try to touch the tip of the index finger outstretched hand to the tip of the nose with the eyes closed, and others.).Disorders of the autonomic nervous system manifested a persistent redness of the skin with its mechanical stimulation (due to the feature of the reaction of the blood vessels in the skin), dry skin, tendency to dermatitis, dystrophic nail changes, increased fragility of hair.

In 1959, the study of chromosomes 9 children suffering from Down's syndrome, found that their cells contain 47 chromosomes.Trisomy 21 th pair of autosomes (three chromosomes instead of two) was detected in all 9 children surveyed.Numerous works of researchers following years, it was confirmed that the basis for Down's syndrome are abnormalities in chromosome numbers, expressed mainly by the presence of one extra chromosome from the group of autosomes.Of particular interest is the fact that many of these children are born to mothers over 35 years old.Analysis of available data confirmed the dependence of the frequency of Down's syndrome by maternal age.The average age of the mother at the time of the patient's birth is 33 years.

is widely believed that the occurrence of Down's disease contribute to "wear and tear of the body", "female genital disease", "functional aging of the reproductive apparatus, in particular of the uterus and the egg," and other factors.An important fact, which may indirectly indicate the possibility of having a child with Down's syndrome is the presence of maternal episodes stillbirth or birth of nonviable children who died in the early period after birth.

probability of having a child with Down's syndrome in mothers of different age groups differs.In women aged 19 to 35 years, it is less than 1 case per 1,000 newborns.Since the age of 35, the likelihood of the patient's birth increases rapidly, reaching between 40 and 50 years of the order of 2% or more.The anomalous set of chromosomes with Down's syndrome can be associated with the breach of certain phases of meiosis.In particular, the fact that the vast majority of children with Down syndrome are born to mothers aged 35 years, allows you to connect the mechanism of this disease with the process of the formation of eggs in a woman's body.The process of oogenesis (formation of female gametes - eggs) begins with the prenatal development the girls before the onset of ovulation.The longer this period is, the greater the likelihood of damage to the egg.At the same time the impact of various environmental factors may have some pathological effect.Age criterion, namely the achievement of 35 years, also plays a role in connection with the fact that in this age period in a woman's hormonal changes the balance.Examination of the chromosome set of parents and relatives of a child with Down's syndrome caused by trisomy 21 autosome, does not reveal specific anomalies.The risk of re-birth of the sick child in the case of trisomy remains the same as in population.

translocation Down syndrome

This syndrome has the second highest rate after trisomy described above.Translocation Down syndrome occurs in 3.5% of children with Down syndrome.SUMMARY syndrome is to transfer the gene or portion of a new chromosome, it is unusual for the position in the same or another chromosome.Differences in emerging manifestations, compared to children with a regular trisomy, no.Of paramount importance for the definition of this syndrome given to the study of chromosomes in patients with children and their parents, because the probability of having a second child with Down syndrome in the case of translocations increases.

involved in the translocation of 13-15 and 21-22-I-I autosomes.The number of chromosomes in a set is normal and is 46. If you have a sick baby translocation Down's syndrome is one of apparently normal parents is often a carrier of the mutation.The frequency of birth of sick children in the mother with the translocation is quite high and is 25%.The probability of a sick child's birth does not depend on the woman's age.A small part of the sick children born from the marriage of a woman with a healthy father - a mutation carrier.Children with translocation syndrome account for 5% of the total number of children with Down syndrome born to mothers under the age of 30 years.In family cases, Down's syndrome translokatsionnys modification of chromosomes detected in approximately 30% of cases.

with Down syndrome mosaicism

third kind of chromosomal abnormality is Down's syndrome mosaicism, when a person is found in certain cells of the normal number of chromosomes, and in others - 47 chromosomes (trisomy on the 21st pair of chromosomes).mosaicism rate is about 1% of children with Down syndrome.

manifestations of the disease in the case of Down's syndrome with mosaicism is largely determined by the ratio of normal and abnormal cells with three 21-mi chromosomes.In some cases, people have the typical features of Down's syndrome, in others - signs of the disease are mild.Intellect children suffer to a lesser extent than in the first embodiment of the disease.Suspected mosaicism arises always with a combination of typical external features of Down syndrome and quite safe intelligence.

cause of mosaicism of chromosome nondisjunction is in the early stages of division of the zygote that leads to the formation of two types of cells: one is contained in 46 and 47 in the other chromosomes.In women with mosaicism and are born normal children, and patients with a first embodiment of Down syndrome.

Among the many changes in Down syndrome occupy a special place specific skin patterns.Skin transverse crease, located in the palm, common in Down's syndrome in the left hand in about half of cases.Another feature of trisomy 21 th pair of chromosomes in the study of skin patterns is the presence of a transverse fold in place on the little finger bends, instead of two, which are usually observed in normal.In addition, there are some changes in the pattern of the skin of fingers, which is determined by fingerprint only by a specialist.

Down's disease is accompanied by a change in laboratory parameters of blood and urine.With regular trisomy usually increases the activity of some enzymes in serum.Most children with Down syndrome were found changes of amino acids in the blood and urine.In some children, an increase of amino acids in the urine may occur.ECG data with Down's syndrome are diverse: from the light rough to conduction abnormalities of cardiac rhythm disorders.

held long-term treatment with low doses of the drug tireoidin When Down syndrome.The beneficial effect is observed in many cases of Down syndrome in the treatment of drug prefizon (30 injections per course of treatment).Niamida application is grounded and its analogue nuredala which are psychoanaleptic drug and possess antidepressant action.The course of treatment with these drugs lasts 2-3 months.By using this group of drugs may have some side effects, which include:. Dizziness, headache, increased sweating, etc., but these adverse effects occur rarely.In diseases of the liver niamid drug is contraindicated.Good effect have drugs that regulate the exchange of substances. Nerobolum, dianabol, etc., also has a favorable influence diet, made by the attending physician taking into account the changes in the blood and urine tests.It is recommended to use funds restorative and supportive therapy, which include calcium supplements, iron, Aloe.As the child grows due attention should be given to training of basic skills of self-service and speech therapy classes.Communicating with children has a team of children with Down syndrome beneficial effect.

Prevention of Down syndrome should be carried out by medical and genetic counseling in specialized genetic centers.Such consultations contribute to the definition of the risk of a patient having a child with a view to resolving the issue of abstinence from childbirth in families with family history, which takes place at Trans-location Down syndrome.

Anomalies autosomes 13-15 and 16-18.Describes syndromes trisomy 13-15 pairs of autosomes and 16-18 pairs of autosomes - trisomy.These syndromes have a number of similarities with Down syndrome.

syndrome caused by trisomy 13-15 pairs of autosomes, occurs on average in 1 child out of 4,000 newborns.For the syndrome characterized by multiple congenital malformations: small eyes, or complete lack thereof, cleft lip, cleft palate, six or more fingers, skull deformation.There have been a variety of malformations of the heart - dekstrapozitsiya, ventricular septal defect, etc. On the part of the gastrointestinal tract in a careful examination reveals a huge gall bladder, narrowing of the common bile duct anomalies provisions of the colon..There may be marked defects of other organs.There are often, umbilical hernia, vascular tumor of the skin.Many children identify stretching of the renal pelvis accumulated in her a lot of urine, the cause of which is the existence of obstacles to its outflow into the urinary tract (hydronephrosis).Later joined by a sharp mental retardation, increased muscle tone, quite often there are seizures caused by underdevelopment and various abnormalities of brain development.

detected extra chromosome group 13-15 In the study of chromosomes children.In the case of a translocation of chromosome abnormalities can be transferred through seemingly healthy parent.For the occurrence of trisomy may be significant maternal age.The average age of mothers "abortions" with trisomy 13-15 chromosomes is 38 years old.

The above congenital defects lead to the early death of patients.Most of them (about 70%) die before the age of 3 months.The cause of death is usually a heart failure, respiratory failure, aspiration, pneumonia acceding.

syndrome trisomy of chromosomes 16-18

This trisomy syndrome occurs more often in comparison with the syndrome trisomy of chromosomes 13-15.The incidence of this syndrome is approximately 1 in 3,000 newborns.In girls, the disease occurs 3 times more often than boys.Children from birth are very small, weak cry.Found the small size of the head, the skull deformation protruding neck, low-set ears, small mandible.Typically an increase in the number of fingers and toes, are often congenital dislocation of the hips.The skin often found vascular tumors.The examination of the internal organs reveal heart abnormalities development: ventricular septal defect, cleft arterial duct.