Trisomy 18, also known as Edwards syndrome, is a chromosomal disorder caused by the presence of an extra 18th chromosome. This condition is associated with severe physical and mental disabilities. Because Edwards syndrome is an example of aneuploidy, the disorder disrupts the normal degree of chromosome number. The greater the number of trisomies, the more severe the abnormalities. Patients with trisomy 18 have multiple developmental defects, including abnormalities of the heart, kidneys, and difficulty with the proper functioning of organs. Children with this disorder often have low birth weight. Unfortunately, life expectancy is often short, and many do not survive past their first birthday.
History of the disease and interesting historical facts
Edwards syndrome was first described in 1960 by Dr. John Edwards, who identified chromosomal abnormalities in newborns. Interestingly, for many years, the condition remained poorly understood by doctors and researchers due to its rarity and difficulty in diagnosing it in early childhood. With the increasing use of prenatal diagnostics such as amniocentesis and ultrasound, earlier detection of the condition has become possible. With the advancement of genetic technology, the study of trisomy 18 and other chromosomal abnormalities has increased, leading to improved research results and understanding of pathogenesis.
Epidemiology
Trisomy 18 is a rare disorder, with an incidence of approximately 1 in 6,000 to 8,000 live births. About 80% cases of this anomaly occur in girls. There is evidence that the likelihood of having a child with trisomy 18 increases with maternal age. Prenatal testing can detect the disorder early in pregnancy, which can influence decision-making during pregnancy. In addition, studies have shown that most cases of trisomy 18 occur spontaneously, with only a small proportion having a family history.
Genetic predisposition to this disease
Trisomy 18 is associated with the presence of an extra chromosome 18, which can occur as a result of an error in cell division called undersegregation. Based on the mutations considered, two main types can be distinguished: complete trisomy (when the entire 18th chromosome is duplicated) and partial trisomy (when only part of the chromosome is duplicated). Such mutations occur randomly during the formation of the egg or sperm, and their underlying cause is currently unknown. The inability to identify specific genetic mutations that contribute to the development of trisomy 18 makes it difficult to prevent this disease.
Risk factors for the development of this disease
There are many risk factors that may contribute to the development of trisomy 18:
- Maternal age – the risk increases with the woman's age; it is especially significant for women over 35 years of age.
- Having previous children with chromosomal abnormalities – if there have been cases of trisomy in the family, this may increase the likelihood of a recurrence.
- Environmental factors – exposure to toxic substances and radiation may be associated with an increased risk of chromosomal disorders.
- Maternal medical conditions – diabetes and other chronic diseases can also significantly affect the outcome of pregnancy.
Diagnosis of this disease
Diagnosis of trisomy 18 includes several stages:
- The main symptoms are low body weight, mental retardation, skeletal abnormalities, heart defects and digestive problems.
- Laboratory tests: blood tests for biochemical and genetic markers.
- Radiological examinations: Ultrasound, which can detect abnormalities in organs early in pregnancy.
- Other diagnostic tests include amniocentesis and chorionic sac biopsy to obtain cells for karyotyping.
- Differential diagnosis: exclusion of other chromosomal abnormalities such as trisomy 13 or monosomy-associated syndromes.
Treatment
There is currently no treatment for trisomy 18 and it is mainly aimed at symptomatic therapy. The main treatment areas include:
- General treatment: support and rehabilitation aimed at improving the quality of life of patients.
- Pharmacological treatment: prescribing drugs to correct heart disease and other associated conditions.
- Surgical treatment: in the presence of critical heart defects or other serious anomalies.
- Other treatments include physiotherapy and bath therapy to improve motor skills and overall physical activity.
List of medications used to treat this disease
- ACE inhibitors for the treatment of heart failure.
- Furosemide – to control water and electrolyte balance.
- Drugs for the correction of metabolic disorders.
- Painkillers to reduce pain.
Disease monitoring
Monitoring the condition of a patient with trisomy 18 requires a comprehensive approach:
- Control stages: regular examinations by specialized doctors, including cardiologists and geneticists.
- Prognosis: Most children with trisomy 18 do not survive beyond their first birthday, although rarer cases may exhibit long-term survival.
- Complications: repeat hospitalizations due to infections, heart failure and digestive problems.
Age-related features of the disease
Trisomy 18 has different age-related manifestations:
- Newborns: multiple malformations, extremely low viability rates.
- Children under one year: high risk of death in case of serious complications.
- Children over one year old: many begin to develop some skills, although mental retardation is overestimated.
Questions and Answers
- What are the main symptoms of trisomy 18? The main symptoms include low body weight, developmental abnormalities, heart and kidney problems, and severe mental retardation.
- Can Trisomy 18 be prevented? At the moment, there are no specific methods of prevention, but prenatal diagnostics allows us to identify abnormalities at an early stage.
- What is the prognosis for children with trisomy 18? The prognosis is often poor; most patients do not survive beyond the first year of life, but rare cases show longer survival with medical support.
- How is trisomy 18 diagnosed? Diagnostics include tests for biochemical markers, ultrasound, amniocentesis and karyotyping.
- How are children with trisomy 18 treated? Treatment is mainly symptomatic and includes drug support, surgical interventions when indicated, and rehabilitation.
