Edwards syndrome – the second most common genetic disease after Down syndrome, associated with chromosomal aberrations. With Edwards syndrome, there is a complete or partial trisomy of the 18th chromosome, as a result of which its extra copy is formed. This provokes a number of irreversible disorders of the body, which in most cases are incompatible with life. The frequency of occurrence of this pathology is one case per 5-7 thousand children, while the majority of newborns with Edwards’ symptom are girls. Researchers suggest that male children die during the perinatal period or during childbirth.
The disease was first described by the geneticist Edwards in 1960, who identified more than 130 symptoms that characterize this pathology. Edwards syndrome is not inherited, but is the result of a mutation, the probability of which is 1%. Factors provoking pathology are radiation exposure, consanguinity between father and mother, chronic exposure to nicotine and alcohol during conception and pregnancy, contact with chemically aggressive substances.
Edwards syndrome is a genetic disease associated with abnormal division of chromosomes, due to which an extra copy of the 18th chromosome is formed. This leads to a number of genetic disorders, which is manifested by serious pathologies of the body such as mental retardation, congenital heart, liver, central nervous system, and musculoskeletal defects.
The incidence of the disease is quite rare – 1: 7000 cases, while most newborns with Edwards syndrome do not live past the first year of life. Among adult patients, the majority (75%) are women, since male fetuses with this pathology die even during fetal development, due to which the pregnancy ends in miscarriage.
The main risk factor for the development of Edwards syndrome is the age of the mother, since nondisjunction of chromosomes, which is the cause of fetal pathology, in most cases (90%) occurs in the maternal germ cell. The remaining 10% of cases of Edwards syndrome are associated with translocations and non-disjunction of the zygote chromosomes during cleavage.
Edwards syndrome, like Down syndrome, is more common in children whose mothers become pregnant over the age of forty. (read also: Causes and symptoms of down syndrome)
To provide timely medical care to children with congenital malformations that are provoked by chromosomal abnormalities, newborns should be examined by a cardiologist, neurologist, pediatric urologist and orthopedist. Immediately after birth, the infant needs a diagnostic examination, which includes ultrasound of the pelvis and abdomen, as well as echocardiography to detect cardiac abnormalities.
Symptoms of Edwards Syndrome
The pathological course of pregnancy is one of the main signs of the presence of Edwards syndrome. The fetus is inactive, insufficient placenta size, polyhydramnios, only one umbilical artery. At birth, babies with Edwards syndrome are characterized by low body weight, even if the pregnancy was delayed, asphyxia immediately after birth.
A number of congenital pathologies of infants with Edwards syndrome lead to the fact that most of them die in the first weeks of life due to heart problems, the impossibility of normal breathing and digestion. Immediately after birth, their nutrition is carried out through a tube, since they cannot suck and swallow, it becomes necessary to artificially ventilate the lungs.
Most of the symptoms are visible to the naked eye, so the disease is diagnosed almost immediately. External manifestations of Edwards syndrome include: shortened sternum, clubfoot, dislocation of the hip and abnormal structure of the ribs, crossed fingers, skin covered with papillomas or hemangiomas. In addition, newborns with this pathology have a specific facial structure – a low forehead, a shortened neck with an excessive skin fold, a small mouth, a cleft lip, a convex nape and microphthalmia; the ears are set low, the ear canals are too narrow, the auricles are deformed.
In children with Edwards syndrome, there are serious disorders of the central nervous system – microcephaly, cerebellar hypoplasia, hydrocephalus, meningomyelocele and others. All these malformations lead to a violation of the intellect, oligophrenia, deep idiocy.
The symptoms of Edwards syndrome are varied, the disease has manifestations from almost all systems and organs – damage to the aorta, heart septa and valves, intestinal obstruction, esophageal fistulas, umbilical and inguinal hernias. From the genitourinary system in male infants, undescended testicles are common, in girls – clitoral hypertrophy and a bicornuate uterus, as well as common pathologies – hydronephrosis, renal failure, bladder diverticula.
Causes of Edwards Syndrome
Chromosomal disorders that lead to the emergence of Edwards syndrome occur even at the stage of formation of germ cells – oogenesis and spermatogenesis, or appear when the zygote formed by two germ cells is not properly crushed.
The risks of Edward’s syndrome are the same as for other chromosomal abnormalities, largely the same as those for Down’s syndrome.
The probability of occurrence of pathology increases under the influence of several factors, among which one of the main ones is the age of the mother. The incidence of Edwards syndrome is higher in women who give birth over the age of 45. Exposure to radiation leads to chromosomal abnormalities, and chronic use of alcohol, drugs, potent drugs, and smoking also contributes to this. Refraining from bad habits and avoiding exposure to chemically aggressive substances in the workplace or region of residence is recommended not only during pregnancy, but also several months before conception.
Diagnosis of Edwards syndrome
Timely diagnosis makes it possible to identify a chromosomal disorder in the early stages of pregnancy and decide on the advisability of preserving it, taking into account all possible complications and congenital malformations of the fetus. Ultrasound examination in pregnant women does not provide enough data to diagnose Edwards syndrome and other genetic diseases, but can provide information about the course of pregnancy. Deviations from the norm, such as polyhydramnios or a small fetus, give rise to additional research, inclusion of a woman in a risk group and increased control over the course of pregnancy in the future.
Prenatal screening is an effective diagnostic procedure to detect malformations at an early stage. Screening takes place in two stages, the first of which is carried out at the 11th week of pregnancy and consists in the study of biochemical blood parameters. Data on the threat of Edwards syndrome in the first trimester of pregnancy are not conclusive, in order to confirm their reliability, it is necessary to pass the second stage of screening
Women who are at risk for Edwards syndrome are advised to undergo an invasive examination to confirm the diagnosis, which helps develop a further behavioral strategy.
Other signs indicating the development of Edwards syndrome are fetal abnormalities detected on ultrasound, an abundance of amniotic fluid with a small placenta, and agenesis of the umbilical artery. Doppler data of the uteroplacental circulation, ultrasound and standard screening can help in the diagnosis of Edwards syndrome.
In addition to indicators of the condition of the fetus and the pathological course of pregnancies, the grounds for enrolling a future mother in a high-risk group are age over 40-45 and overweight.
To determine the condition of the fetus and the characteristics of the course of pregnancy at the first stage of screening, it is necessary to obtain data on the concentration of PAPP-A protein and beta subunits of chorionic gonadotropin (hCG). HCG is produced by the embryo itself, and as it develops, by the placenta surrounding the fetus.
The second stage is carried out starting from the 20th week of pregnancy, includes the collection of tissue samples for histological examination. Cord blood and amniotic fluid are best suited for these purposes. At this stage of perinatal screening, it is possible to draw conclusions about the child’s karyotype with sufficient accuracy. If the result of the study is negative, then there are no chromosomal abnormalities, otherwise there are grounds for making a diagnosis of Edwards syndrome.
Treatment of Edwards syndrome
As with other genetic diseases caused by chromosomal abnormalities, the prognosis for children with Edwards syndrome is poor. Many of them die immediately at birth or within a few days, despite the medical assistance provided. Girls can live up to ten months, boys die within the first two or three. Only 1% of newborns survive to the age of ten, while independence and social adaptation are out of the question due to serious intellectual disabilities.
More likely to survive in the first months in patients with a mosaic form of the syndrome, since the damage does not affect all cells of the body. The mosaic form occurs if chromosomal abnormalities occurred at the stage of zygote division, after the fusion of male and female germ cells. Then the cell in which there was a nondisjunction of chromosomes, due to which trisomy was formed, during division gives rise to abnormal cells, which provokes all pathological phenomena. If trisomy occurred at the stage of gametogenesis with one of the germ cells, then all cells of the fetus will be abnormal.
There is no drug that could increase the chances of recovery, since it is not yet possible to interfere at the chromosomal level in all cells of the body. The only thing that modern medicine can offer is symptomatic treatment and maintaining the viability of the child. Correction of pathological phenomena associated with Edwards syndrome can improve the patient’s quality of life and prolong its life. Surgical intervention for congenital malformations is not advisable, as it entails great risks for the patient’s life and has many complications.
Patients with Edwards syndrome from the first days of life should be observed by a pediatrician, as they are very vulnerable to infectious agents. Among newborns with this pathology, conjunctivitis, infectious diseases of the genitourinary system, otitis media, sinusitis, and pneumonia are common.
Parents of a child with Edwards syndrome are often concerned about the question of whether it is possible to give birth again, what is the likelihood that the next pregnancy will also be pathological. Studies confirm that the risk of recurrence of Edwards syndrome in the same couple is very low, even compared with an average probability of 1% of cases. The probability of having another child with the same pathology is approximately 0,01%.
In order to timely diagnose Edwards syndrome, expectant mothers are advised to conduct antenatal screening during pregnancy. If pathologies are detected in the early stages of pregnancy, it will be possible to have an abortion for medical reasons.