Trisomy 14

Trisomy 14

Trisomy 14 is the result of a genome mutation. The symptoms depend on the type of mutation. According to studies, trisomy 14 often leads to miscarriages.

What is trisomy 14?

There is a difference between gene mutations and genome mutations. In the case of gene mutations, certain nucleotides are missing, some nucleotides are swapped, or additional nucleotides are added. In a genome mutation, the entire genome is affected. This means that there are additional chromosomes or chromosomes are missing or swapped. Trisomy 14 is based on such an altered number of chromosomes. For lenz-majewski syndrome definition and meaning, please visit eshaoxing.info.

This is a complex of disabilities that is caused by the triple execution of the genetic material on chromosome 14. There are two copies of chromosome 14 in a healthy person. A triple execution therefore corresponds to a genome mutation. Trisomy 14 exists in different variants and shows variable clinical symptoms depending on the subspecies.

In addition to mosaic and partial trisomy 14, medicine knows a so-called translocation trisomy 14 and a free form of the disease. Different types of mutation underlie these subspecies. Partial trisomy 14 is most commonly observed in living organisms. Since the first description, only slightly more than 20 case studies on living patients could be documented.

Causes

Genome mutations are caused by genetic material. In mosaic trisomy 14, not all cells of chromosome 14 are present in triplicate. At the same time as the trisome cell line, there is a cell line with a diploid set. This means that several karyotypes are present at the same time. In partial trisomy 14, two sets of chromosome 14 are present in all cells except germ cells.

However, since one of the chromosomes is elongated and divided into two in a certain section, some of the genetic information is still present in triplicate. In translocation trisomy 14, chromosome 14 is present in triplicate in all cells. One embodiment of the three chromosomes attaches, in whole or in part, to one of the other two chromosomes and thus relocates. Free trisomy 14 is also based on the triple execution of chromosome 14 in all cells of the body.

However, there is no shifting in this form. According to the current state of knowledge, girls are more frequently affected by trisomy 14 than boys. Most fetuses with trisomy 14 die during pregnancy. This connection often underlies early miscarriages. According to one study, 15 of 776 miscarried fetuses suffered from trisomy 14.

Symptoms, Ailments & Signs

In trisomy 14, the clinical symptoms depend on the percentage of triisomer cells or are determined by the section of chromosome that is present with the trisomy. For this reason, symptomatic generalizations are difficult to make. Abnormally high levels of amniotic fluid are common in women with affected fetuses during pregnancy.

Prematurity before the 37th week of pregnancy is also one of the most common symptoms. Even in the womb, fetuses often suffer from delayed growth. After birth, there are additional psychomotor delays in development. Growth is often asymmetrical. Displaced hips or laterally different limbs can occur. People’s fingers or toes often overlap.

Organic defects such as heart defects may be present. In addition to microcephaly, facial deformities such as a broad forehead or low-set ears, a broad bridge of the nose or facial asymmetry are often present. Facial symptoms may also include a long philtrum, a cleft palate, an abnormal palate, and a small mandible with a protruding maxilla.

The same goes for a large mouth opening, unusually full lips, and deep-set, small, wide-set eyes. Patients often also have narrow eyelids and slightly drooping upper eyelids. In many cases there is a translucent film on the eyes. Patients’ skin is often hyperpigmented. The most common changes in the urogenital tract include an abnormally small penis and undescended testicles. These symptoms are often associated with renal failure and cognitive impairment.

Diagnosis & course of disease

Prenatally, fetuses with trisomy 14 already show abnormalities in the ultrasound, which can be a sign of the trisomy for the gynecologist. The free form and the mosaic form of the disease can essentially be diagnosed without a doubt using invasive diagnostic methods, above all with the help of amniocentesis or chorionic villus sampling.

However, chorionic villus sampling is considered error-prone and can result in a false positive diagnosis. A postnatal suspected diagnosis is already based on the characteristic physical features of the patient and is usually confirmed or ruled out by means of molecular genetic analysis. The prognosis depends on the particular mutation and the symptoms in the individual case.

Complications

Trisomy 14 is associated with various symptoms, all of which have a very negative effect on the quality of life of those affected. First and foremost, this leads to a clearly delayed growth and also to a delayed development of the patient. The disease can therefore be diagnosed in the womb.

Furthermore, those affected suffer from a cleft palate, so that there can be complications when taking food and liquid. Heart defects also occur frequently due to trisomy 14 and can also negatively affect the life expectancy of the child. Due to the malformations in the face, many of those affected, especially in childhood, suffer from bullying or teasing and thus possibly from psychological upsets.

Renal insufficiency can also occur, so that in the worst case the patients are dependent on dialysis or a donor kidney. Since trisomy 14 also leads to mental retardation and thus to cognitive and motor impairments, those affected are usually dependent on the help of other people in their everyday life.

Since direct treatment cannot take place, there are no particular complications. Only the individual complaints are alleviated by different therapies. In many cases, the parents and relatives are also dependent on psychological treatment.

When should you go to the doctor?

In the case of trisomy 14, a visit to a doctor is definitely necessary. This disease can be fatal if left untreated, so investigation and subsequent treatment must be carried out in any case. Self-healing cannot occur in this case. Early detection of trisomy 14 always has a very positive effect on the further course of the disease. A doctor should be consulted for trisomy 14 if the person affected suffers from malformations or malformations that can affect the entire body. In many cases, heart defects can also indicate the disease and should be checked by a doctor. Renal insufficiency is also often an indication of trisomy 14.

Since the disease cannot be completely treated, the relatives and parents of the person affected often depend on psychological treatment to prevent depression or other mental upsets. The treatment of the person concerned depends heavily on the exact symptoms and is carried out by the respective specialist. If you want to have children again, genetic counseling should be carried out.

Treatment & Therapy

There is currently no causal therapy available for patients with trisomy 14. Only gene therapy approaches could be considered as causal therapy. However, these approaches have not yet reached the clinical phase. For this reason, the trisomy is currently only treated symptomatically. The treatment depends on the symptoms in the individual case.

The organic deformities and insufficiencies are the focus of therapy. For example, the heart defect is corrected as early as possible in an invasive surgical procedure. Children’s renal insufficiency also requires early intervention, which initially may consist of dialysis. In the long term, a kidney transplant is the most sensible way of treatment. The deformities of the face do not necessarily have to be treated. Therefore, they are often initially ignored.

More important is early support for the cognitively improved development of children and physiotherapeutic promotion of motor skills. Since not all patients with trisomy 14 have symptoms such as a heart defect, delayed development or renal insufficiency, some of those affected are relatively symptom-free throughout their lives and then do not have to seek therapy.

Prevention

Since trisomy 14 is a genetic mutation, there are hardly any preventive measures available. Since prenatal diagnosis is possible, the parents of affected fetuses may decide not to have the child.

Aftercare

Live-born children with trisomy 14 benefit from early therapeutic education. This should be adapted to the individual abilities of the child. Since this chromosomal disorder in the living patient is usually a partial trisomy or a mosaic trisomy, the clinical picture also varies greatly.

The physical symptoms therefore also require individual assessment and follow-up treatment. While in some cases the focus is on preventing pain and suffering, others may be successful in learning various skills of daily living. In most cases, children with a free trisomy 14 die in the womb.

Such a miscarriage is stressful for the parents concerned, which can make psychological follow-up care necessary. How long this lasts depends on the wishes of the parents and the individual situation. By consulting human genetics, an attempt is made to clarify the cause of the genetic defect. In this way, the risk of recurrence can be better assessed.

In most cases, this is not significantly increased. In the case of a subsequent pregnancy, an amniotic fluid test or a chorionic villus biopsy can be carried out at the mother’s request. This means that a renewed trisomy 14 can already be detected during pregnancy. However, these tests also increase the risk of miscarriage.

You can do that yourself

The symptomatic treatment of trisomy 14, which includes surgery, medication and physiotherapy, can be effectively supported by a whole range of self-help measures.

First of all, it is important to support the affected child as best as possible in everyday life. Physiotherapy and mental training can also be carried out outside of inpatient therapy. It is best for parents to talk to a specialist who can recommend suitable measures to correct the individual malformations as best as possible.

Talk therapy is also useful for the child. Smaller children in particular ask many questions about their illness, which the parents themselves cannot always answer. Therefore, an expert must be consulted to educate the child as best as possible. Child-friendly books about the hereditary disease also help to build a healthy relationship to the disease.

In addition, the parents must keep a close eye on the child so that they can react quickly in the event of complications. The apartment must be equipped for disabled people so that there is no risk of falls or accidents. In addition, suitable special schools and kindergartens for the sick child should be sought at an early stage, since the registration deadlines are often several years.

Trisomy 14