Jacobsen syndrome is a rare genetic disorder. The condition is associated with growth retardation, mental retardation, heart defects, and limb abnormalities.
What is Jacobsen syndrome?
Jacobsen syndrome is a rare chromosomal abnormality and is also called distal 11q deletion syndrome. A section is missing from chromosome number 11. The disease is very rare. Little is known about the syndrome, which was discovered by Danish physician Petra Jacobsen. So far, about 80 cases have been documented. The frequency is given as one case of the disease per 100,000 newborns. Girls are affected more often than boys. The ratio is about 2:1. Both physical and mental development are disturbed. Affected individuals can be visually identified by external malformations. Among other things, a mongolian wrinkle at the eyes, a short neck, a broad short nose, a drooping lower lip and a V-shaped mouth are present. Affected individuals exhibit mild (IQ less than 80) to moderate (IQ less than 50) intellectual disability. This reduction in intelligence leads to language and cognitive deficits. Verbal expression in particular is far below children of the same age.
Causes
The cause of Jacobsen syndrome is the loss of a chromosomal segment of the eleventh chromosome. A mutation (deletion) has occurred in the q arm of chromosome number 11. A lot of gene information is lost as a result. According to the latest scientific findings, this deletion is inherited from the father in 15 percent of those with the disease. The cause is an unsuccessful transmission of the parental genes. In about 85 percent of cases, the genetic mutation occurs spontaneously, i.e. without an inherited predisposition. As a result of this genetic change, a defective protein is produced. Why these genetic changes can happen is still unclear.
Symptoms, complaints and signs
Symptoms occur from birth and affect the entire body. Typically, there are deformities in the head region, such as a short neck, high palate, or drooping eyelids. Facial dysmorphia can be recognized by a small triangular-shaped head with a protruding forehead. Affected individuals occasionally have abnormalities of the eyes (for example, glaucoma, cataracts, strabismus). Heart defects occur in about half of those with the disease. Cognitive performance varies among sufferers. In most cases, the classification is mild to moderate mental retardation. Normal mental development is rarely encountered. Mainly cognitive and linguistic abilities are limited. Affected persons can express themselves poorly verbally, in comparison better understand language. Restrictions in fine and gross motor skills are common. In more than 90 percent, there is a reduction in blood platelets (thrombocytes). As a result, patients with the disease have an increased tendency to bleed. Changes can be seen in the hands and feet, such as a hammer toe, underdeveloped nails, supernumerary fingers or webbing. Rarely, affected individuals suffer from growth disorders, abnormalities of the genitals, hernias, and changes in the kidneys.
Diagnosis and course of the disease
The majority of affected children are born normal and the syndrome is detected in the first months of life. In such cases, the heart defect and blood count with altered blood components are detected first. Due to the rarity of the chromosomal defect, physicians are often baffled. Parents of affected children report a medical ordeal lasting months or years until diagnosis. Life expectancy is limited. About one-fifth of affected children die in the first two years of life. Bleeding or the congenital heart defect are crucial for early death. In addition, a tendency to recurrent infections has a negative effect. If the affected child undergoes heart surgery, receives regular blood transfusions and early intervention, the quality of life can be improved. The life expectancy of those children who survive beyond two years is unknown because of the rarity of Jacobsen syndrome.
Complications
Jacobsen syndrome causes the patient to experience a number of different disorders and complaints that usually complicate daily life and significantly reduce quality of life. In most cases, affected individuals suffer from growth disorders and mental retardation in the process.As a result, they are not infrequently dependent on the help of other people in everyday life. Heart defects also occur. If left untreated, these can lead to the death of the affected person in the event of sudden cardiac death. It is not uncommon for the limbs to be affected as well, resulting in various malformations and anomalies. Especially in children, Jacobsen’s syndrome can therefore lead to teasing or bullying and create severe depression or other psychological upsets. It is not uncommon for the children’s parents to suffer from psychological distress as well. It is not possible to treat Jacobsen syndrome causally. Therefore, the treatment is mainly based on the symptoms and aims at increasing the life expectancy. As a rule, no further complications occur. However, the affected person is dependent on regular examinations.
When should one go to the doctor?
In most cases, newborns are examined extensively by obstetricians as well as pediatricians immediately after birth and in the following months. Since possible irregularities of Jacobsen syndrome can already be noticed and diagnosed within these examinations, the parents of the child do not necessarily have to become active in case of abnormalities and irregularities. If automatic examinations do not take place or if initial symptoms go unnoticed during checkups, a visit to the doctor is necessary as soon as physical peculiarities or abnormalities become apparent in the first months of life. If feeding is refused, the infant hardly reacts to external stimuli or the eye position is unusual, a doctor should be consulted. If there is a fixed gaze or a permanent squint, there is a condition that should be diagnosed. Deformations of the head, a short neck or an unusual appearance of the forehead are indications that should be clarified by a doctor. If mental disturbances, developmental delays in speech or gross motor movements become apparent in the further course of development, a visit to the doctor is advisable. An increased tendency to bleed and visual changes in the limbs are further signs of Jacobsen’s syndrome that should be medically investigated. Diagnosis is made by detecting a genetic change. Therefore, if symptoms include cardiac rhythm disturbances or irregularity of cardiac activity, further investigation is necessary to clarify the cause.
Treatment and therapy
The syndrome is usually recognized at a young age in affected individuals. In some patients and female patients, surgery must be performed. Interventions on the hearts of affected children are often performed shortly after birth. Regular blood checks and transfusions are necessary throughout life. Frequent visits to specialists are necessary. Affected persons with restrictions of the optical system require close-meshed ophthalmological treatment. Internal medicine examinations are performed because of the organic damage. Orthopedists are consulted for foot and hand deformities. The quality of life can be improved by speech therapy. Speech promotion improves the expressive ability of the sick children. It makes sense to start early intervention and physiotherapy as soon as possible. Early intervention is a collective term for educational and therapeutic measures for children with disabilities. Through playful methods, the development should be supported already in the first years of life. The degree of mental handicap cannot be significantly reduced, but the quality of life can be improved. Work is also done with the parents so that they can support the child well at home. Physiotherapy is recommended for the improvement of fine and gross motor skills. Children with the syndrome will most likely not be able to start school as usual. Supportive measures are appropriate to allow for as normal a school career as possible. Therapies and treatments for Jacobsen syndrome can improve symptoms but not cure them. Sufferers depend on medical and therapeutic help throughout their lives.
Outlook and prognosis
The prognosis of Jacobsen syndrome is unfavorable. It is a genetic disease that cannot be fully treated with current medical and legal options. Because of existing laws, no alteration of human genetics is allowed. Therefore, a symptomatic therapy of the individually occurring complaints is carried out.If medical care is not sought, the already impaired quality of life is further reduced. In addition, the already reduced life expectancy is significantly reduced by another. Due to the multitude of complaints, treatment is absolutely necessary for this disease. Normally, different therapy approaches are pursued in parallel in order to improve the patient’s quality of life as well as to extend the existing life expectancy. The sooner therapy is started, the more successful the results. Despite all efforts, a complete cure is not achieved in this disease. Optical changes or deformities are corrected by surgical interventions if necessary. The goal of the interventions of the always the optimization of the well-being and the improvement of the health impairments. A large number of patients die in the first two years of life. The disease results in a congenital heart defect. In many infants, this is irreversible or, because of a generally weakened state of health, no surgical intervention can be performed that the patient would survive.
Prevention
Jacobsen syndrome sometimes becomes apparent on ultrasound before birth. Despite a problem-free pregnancy, the unborn baby may be small and underweight. The mother may consent to prenatal testing. During an examination of the amniotic fluid, genetic material is taken. If the probability of a genetic defect is high, the pregnancy can be terminated. There is a possibility of Jacobsen syndrome being passed on to further children. Preventive measures against a gene mutation are not known. It is important in any pregnancy to promote the health of the child through a healthy lifestyle.
Follow-up
Children with Jacobsen syndrome require medical care and management by a multidisciplinary field during the follow-up period after diagnosis. Complications and life-threatening situations are caused by the children’s severe heart defects and can greatly affect their ability to live. In addition, the blood picture is altered in such a way that there is a high and life-threatening susceptibility to infections in everyday life. The congenital deficit in the production of thrombocytes permanently leads to an increased risk of bleeding. Due to the mental disability, the children are permanently dependent on support and assistance in everyday life. In most cases, independent living is not possible. However, regular follow-up examinations can lead to the need for and help with appropriate medical treatments that significantly improve the child’s quality of life and life expectancy (for example, heart surgery, blood transfusions). Through physiotherapeutic and occupational therapies and early intervention, the child’s suffering can be eased somewhat and resources of the developmental state can be used and preserved. Aromatherapy, sound therapy, music therapy and light therapy can be used to stimulate the child’s senses. An important point in the follow-up treatment of children with Jacobsen’s syndrome is the work, counseling and support of the families in coping and dealing with the sick child. In this way, the child’s abilities and skills can be identified, used, maintained, and supported together.
What you can do yourself
Regular check-ups with the family doctor and specialists such as the cardiologist or orthopedist are essential if Jacobsen’s syndrome is present. If the eyes are affected by the disease, parents should also visit the ophthalmologist with their child at short intervals. In addition, those affected can take some measures to improve their child’s quality of life. These include visits to a speech therapist. The speech therapist can effectively promote the child’s ability to express himself through special exercises to promote speech. Physical therapy is also useful to help the child develop motor and fine motor skills. All therapeutic and educational measures on children with physical and/or mental disabilities are summarized under the term early intervention. Since the symptoms of Jacobsen’s syndrome vary greatly, parents should seek discussion with their pediatrician to clarify which forms of therapy are most advisable for their own child.Especially in the first years of life, parents can also support their child through playful methods. This does not reduce the degree of disability – but it is still possible to improve the quality of life. Since living with a child suffering from Jacobsen’s syndrome is a great emotional burden, parents should also not be afraid to seek help in case of doubt – be it from doctors, psychologists or educators.
