Prader-Willi syndrome - a genetic rare anomaly characterized by stop working genes, or in a scientific phenomenon caused by lack of expressing that means the transfer of genetic information from DNA to RNA.The function of genes in this case is the inclusion in work it in his time.For example, boys have no hair growth on the face as a child, and begins this phenomenon after the onset of puberty.The disease was first described in 1956.
Prader-Willi syndrome occurs with a frequency of one case per 12 000 children born.The disease is described in the works of Heinrich Willi Andrea Prader, Andrew Ziegler, Alexis Labhart, Guido Fanconi.
Prader-Willi syndrome causes
The disease is characterized by absence or by expressing the seven genes from the fifteenth chromosome inherited from the father.Prader-Willi syndrome is marked by changes in the paternal chromosome, and in case of changes in the maternal chromosomes observed Angelman Syndrome.
The gene set, causing the occur
Prader-Willi syndrome symptoms
for this disease is characterized by hip dysplasia, hypotonia (low muscle tone), obesity (overeating preconditions arise for the 2nd year).People with Prader-Willi syndrome have a reduced coordination of movements, as well as low bone density, are owners of small feet and hands, low growth, prone to sleep, strabismus, have curvature of the spine.For such people, characterized by thick saliva, hypogonadism (decreased function of the sex glands), the presence of bad teeth, infertility.Patients are characterized by a delay of mental and speech development delay puberty and have difficulty in mastering motor skills.
Prader-Willi syndrome and symptoms of this disease visually observed high bridge of the nose, narrow and high forehead, almond-shaped eyes, narrow lips.All of these signs and symptoms do not appear on a single patient.Often found in patients up to five of the above symptoms.
Prader-Willi syndrome diagnosis
The disease can be diagnosed before birth.This is evidenced by the low mobility of the fetus or child are often the wrong position, and polyhydramnios (amniotic fluid in excessive amounts).
Prader-Willi syndrome is often diagnosed after genetic analysis.This analysis makes a newborn hypotonicity (low muscle tone).Sometimes doctors are wrong and diagnose Down syndrome and myopathy.Signs of diagnosing the disease after birth include: birth through caesarean section, breech presentation, hypotension, lethargy, weak sucking reflex because a baby weakened muscle tone, difficulty breathing, hypogonadism.
Children with Prader-Willi syndrome are similar to each other, so an experienced geneticist at once diagnose the disease, even without waiting for the results of blood tests.
Prader-Willi syndrome and Angelman syndrome
Today we know one more disease that relate to nursing disease Prader Willi syndrome.This disease is called Angelman.For it is characteristic of the mutation in the mother's genetic material.The results of most independent studies suggest such causes of this disease as a mutation in the gene.The product of this gene is the enzyme component of the entire complex of protein degradation.This disease is named after the British pediatrician Harry Angelman out, described it in 1965.
Prader-Willi syndrome treated
disease, being a congenital genetic abnormalities is not fully known, and its treatment methods have not been developed.
How to treat Prader-Willi syndrome?Yet there are some therapeutic measures that improve the quality of life.For example, children with hypotonicity need a massage, as well as other kinds of special treatment.Displaying the use of special techniques that improve the development of the child, as well as sessions with a speech therapist and defectology.Children 7, 8, 9 years old with Prader-Willi syndrome are appointed by growth hormones, also shows the use of hormonal therapy with gonadotropins.
Prader-Willi syndrome is manifested in boys hypogonadism, microfoam and cryptorchidism (no testicular descent).In this situation, doctors recommend to either wait until the testicles descend on their own, or recommend surgery with hormone therapy.To adjust the increase in weight is assigned to a diet that restricts the amount of carbohydrates and fats.If obesity is already available, it is necessary to monitor the number and quality of the food, which is absorbed in patients with Prader-Willi syndrome.For such people is peculiar ravenous appetite.Possible complications of the disease sleep apnea, characterized by a delay of breathing during sleep.
Prader-Willi syndrome forecast
When planning a second child from the parents of most of these possible re-emergence of the disease risk.It depends on the mechanism that causes a genetic fault.The risk is less than 1% in cases where the first child has a deletion of the gene or uniparental disomy parthenogenetic.The risk is up to 50%, provided that the failure is caused by a mutation.The risk of up to 25% remains in the translocation of parental chromosomes.In any case, parents need to do genetic testing.
Prader-Willi syndrome, and its prognosis is often maintains a delay of speech and mental development.Studies Freeman and Kerfs showed that 5% of patients have IQ is the average level.This equates to 85 with three more points on a scale IQ.27% of patients with a level of intelligence on the verge average, which is calculated 70-85 points.34% of patients have IQ scores corresponding to 50-70.27% of patients remains at the level of the average backlog and estimated 35-70 points.5% of patients have a strong backlog and gain 20-35 points, and less than 1% have a significant backlog.Other studies have data that 40% of patients showed an average or reduced intelligence.
Typically, children with Prader-Willi syndrome and have good long-term visual memory.They are able to learn to read, have a passive-rich dictionary, but their own speech is often worse than her understanding.Also suffering and does not meet the standards of the age auditory memory, writing skills and math skills, visual and auditory short-term memory.
Prader-Willi syndrome is often accompanied by increased appetite, because cases rises in the blood levels of the hormone ghrelin.For patients with reduced concentrations typical somatoliberin.Some attribute this to the 15th chromosome, with connections to the hypothalamus.Other evidence suggests reducing the total number of cells, and cells comprising oxytocin in the paraventricular hypothalamic nuclei.But interestingly, there are data that suggest otherwise: the autopsy of the dead with the disease often shows no defects of the hypothalamus.