The diagnosis of Hurler’s disease is not only associated with enormous psychological and physical stress for those affected, but also for the parents, since the disease not only has extremely complex but also serious symptoms. According to the current state of medicine, Hurler’s disease cannot be cured. Those affected must be treated with bone marrow or hematopoietic stem cell transplantation (BMT) and enzyme replacement therapy in infancy or early childhood. This is the only way to get past puberty.
What is Hurler’s disease?
The diagnosis of Hurler’s disease defines the most severe form of the lysosomal storage disease mucopolysaccharidosis type I (MPS I). The pediatrician Gertrud Hurler described the course of this rare lysosomal storage disease with skeletal deformities and delayed motor and intellectual development for the first time. The designation is derived from your name. See homethodology for Lethargy Overview.
Currently, a distinction is increasingly being made between MPS I including involvement of the central nervous system (ZMS) and MPS I without involvement. However, the CNS is always involved in Hurler’s disease. Fortunately, this disease occurs very rarely. The estimate is around 1:145,000 births. However, Hurler’s disease occurs most frequently at 1:100,000.
Hurler’s disease, also known as Hurler-Pfaunder syndrome, is caused by mutations in the IDUA gene that cause a defect or complete loss of activity in the enzyme alpha-L-iduronidase. The consequence of this is an accumulation of glycosaminoglycans (GAG) and a disruption in cell metabolism.
Due to the enzyme defect, minoglycans can no longer be broken down and broken down to a sufficient extent. Rather, they are stored in the lysosomes of body cells. Above all, dermatan sulphate and heparan sulphate accumulate. This severely impairs cell function, causing the symptoms that lead to Hurler’s disease.
Symptoms, Ailments and Signs
The symptoms, the symptoms, are very extensive and usually already present in infancy. Short stature and recurring otitis as well as obstructive and restrictive respiratory problems, often in connection with pulmonary infections, characterize the clinical picture.
Umbilical and inguinal hernias, some of which recur, hip dysplasia on one or both sides, as well as a gibbous (humpback of the spine) and various joint contractions or joint stiffness are also part of the clinical picture. Compression of the spinal cord in the area of the upper cervical spine (cervical spine) at the craniocervical junction is also a frequently occurring symptom.
Carpal tunnel syndrome, often bilateral, often occurs in childhood. The eyes often suffer from corneal opacity in the third year of life, the hearing increasingly develops hearing impairment and the tongue enlarges (macroglossia). Sleep apnea and mental retardation can also occur. The head is relatively large and the lips are often widened.
Organomegaly (abnormal enlargement of organs) as well as hernias and hirsutism (increased androgen-dependent hair growth) can also occur. Cardiomyopathy with valvular dysfunction is also frequently observed. A typical appearance can be observed in affected patients. These include a short neck, an enlarged tongue and a deep bridge of the nose.
Growth is usually normal up to the age of three. However, developmental delays can occur between the 12th and 24th month of life. Hydrocephalus can also occur in the second year of life. The growth often ends at a height of 1.20 meters. The gait pattern is also very characteristic due to the malpositions.
Not only the already mentioned enlargement of the tongue, but also a narrowing of the airways and the reduced elasticity of the lung tissue are responsible for restricted breathing. Corneal opacity can progressively affect vision over time.
Diagnosis and course of the disease
A diagnosis of Hurler’s disease can be made with a [[blood sample|]blood test to determine the enzyme activity of alpha-L-iduronidase. Prenatal diagnosis using enzymes and molecular genetics is also possible.
The clinical picture can be divided into three forms because the enzyme defect is based on different mutations. The three progressions are:
- Severe Hurler’s disease
- Hurler/Sheie’s disease (M. Hurler/Scheie) in a moderate form
- Morbus Scheie (M. Sheie) in a mild form
Typically, Hurler’s disease causes a variety of symptoms and complications. The symptoms of this disease severely restrict the everyday life of those affected, so that in most cases they are also dependent on the help of other people or on the help of parents and carers. The quality of life of those affected and their parents is also significantly reduced and restricted.
Patients usually suffer from severe short stature and breathing difficulties. These can continue to lead to shortness of breath and, in the worst case, to the death of the patient. The joints are also stiff and usually cannot be moved easily. This leads to movement restrictions and a strong delay in the development of the child.
In most cases, the patient also has problems with their eyesight and hearing, so that in the worst case they can go completely blind or lose their hearing due to Hurler’s disease. Furthermore, this disease also leads to retardation, so that the patients are dependent on special support. Unfortunately, the disease itself cannot be cured, so that only a few symptoms can be limited. In many cases, the parents and relatives also need psychological treatment.
When should you go to the doctor?
Children with Hurler’s disease already show clear symptoms of the disease. You need medical help immediately after discovering the first irregularities, as the symptoms are very detrimental to the patient’s quality of life. If you have breathing problems, frequent infections or short stature, you should consult a doctor. If a suspension of respiratory function is noticed during the night’s sleep, this should be discussed with a doctor. Mobility complications are also a concern. Joint stiffness, irregular movements and problems with locomotion should be presented to a doctor.
Optical abnormalities or deformations of the skeletal system are signs of a health disorder. If the functionality of the hand is restricted or if the cornea becomes cloudy, a doctor is needed. Reduced development of mental skills, a learning disability or language development disorders should be clarified by a doctor.
General growth disorders, hydrocephalus, an enlarged tongue or a deep bridge of the nose are characteristic of Hurler’s disease and should be presented to a doctor as soon as possible. Normally, the disorders are clearly recognizable from the second year of life. A limitation of hearing or vision are further indications of an existing disorder and must be examined medically.
Treatment & Therapy
In any case, treatment should be carried out by a multidisciplinary team of doctors and therapists. If the central nervous system is affected, treatment as early as possible in the form of a bone marrow or hematopoietic stem cell transplant (BMT) is called for. This should be carried out on toddlers up to the age of 2.5 years.
The transplant contains blood cells that produce the enzyme alpha-L-iduronidase. In return, these cells release part of the formed and intact enzyme to the environment. This is then taken up by other body cells and transported to the lysosomes. The stored glycosaminoglycans can now be broken down again.
Only through a transplant can cognitive development and thus life expectancy be positively influenced. In addition, enzyme replacement therapy is carried out afterwards. The defective enzyme is replaced by a biotechnologically produced form of the human enzyme. Now the pathological storage of glycosaminoglycans can be broken down again.
However, due to a blood-brain barrier, the enzyme replacement does not get into the central nervous system. As a result, this form of therapy cannot influence cognitive and motor symptoms. According to the current status, only stem cell transplantation can do this. In the run-up to the transplantation, the general condition of the patient can be stabilized or improved with enzyme replacement therapy.
It can also support the transplant and alleviate the symptoms. BMT cannot cure Hurler’s disease. In purely prognostic terms, patients with such therapy can reach early adulthood before dying from cardiovascular and respiratory complications.
Outlook & Forecast
The disease is not only an enormous psychological and physical burden for those affected, but also for parents, because Hurler’s disease not only has complex but also very serious symptoms. According to current knowledge, the disease cannot be cured. The patients have to be treated in early infancy with a special bone marrow or stem cell transplant, as well as enzyme replacement therapy. This is the only way to prolong life beyond puberty.
In most cases, the disease causes many different symptoms and complications. The effects of the disease limit the lives of patients significantly, so that they are often dependent on the help of carers or on the family. In addition, the quality of life of those affected and their families is significantly reduced and restricted. Patients often suffer from a very pronounced short stature and have severe breathing difficulties.
These often lead to shortness of breath and, in extreme cases, to the death of the person concerned. In addition, the joints are often stiff and difficult to move without pain. This leads to movement restrictions and severe developmental delays in the affected children. Patients often experience problems with hearing and vision, so that they can even go completely blind and lose their hearing as a result of the disease.
Hurler’s disease is a congenital genetic defect. Therefore no preventive treatment can be given. With a view to genetic engineering, however, the future should be viewed positively.
Hurler’s disease is based on a genetic defect and takes a severe course in most cases. Those affected can only contribute to the treatment to a very limited extent. At the beginning of the illness, self-help measures are usually limited to taking advantage of psychotherapeutic offers that can make it easier for the patient to accept the illness.
Self-help groups, in which there is an exchange with other sufferers, often help to discover new life perspectives and to master everyday life with this serious illness. A living environment that is suitable for the disabled enables those affected to have more freedom of movement. Talk and behavioral therapies often support the patient’s mental process of dealing with the disease.
In the advanced stage of the disease, help from trained nursing staff is often required. Of course, the support of relatives and friends can also have a positive influence on the lifestyle of the person concerned. Moderate exercise, avoidance of psychological stress and a special diet also help to improve the situation.
A complaint diary can help identify unusual symptoms and conditions early to prevent life-threatening complications. Constant communication with the doctor treating you is indispensable. In the last stage of the course of the disease, the relief measures are limited to the administration of pain-relieving medication, which is to be taken according to the doctor’s prescription.
You can do that yourself
Hurler’s disease usually takes a serious course and can only be treated to a limited extent by those affected. Accordingly, the most important self-help measure focuses on taking advantage of psychotherapeutic measures. Talking to a therapist on the one hand and attending a self-help group on the other offer the sufferer opportunities to accept the illness. In addition, a new perspective on life can be developed in conversation with other affected people.
In addition, steps must be taken to make everyday life with the disease easier. This can be the installation of a disabled facility, but also behavioral and talk therapies. People who have advanced Hurler’s disease need professional care. Friends and relatives can be an important support during this time.
The doctor will also recommend measures such as changing your diet, exercising, and avoiding stress. This and a complaints diary can lead to a relatively symptom-free life despite illness. The prerequisite for this is that all symptoms and unusual complaints are reported to the doctor. Failure to do so can result in life-threatening complications that require further treatment. In the last stages of the disease, self-help measures focus on taking the pain-relieving medication as directed by the treating physicians.