Hajdu-Cheney Syndrome 101
Hajdu -Cheney syndrome is a rare bone disease. The cause is apparently a genetic and autosomal dominant inherited gene mutation. Due to the limited number of cases, standardized treatment measures have so far hardly been available.
What is Hajdu-Cheney Syndrome?
Osteolysis is understood in medicine as an active dissolution of bone tissue. Human bones are a living organism that undergoes changes and remodeling processes throughout life. In moderation, osteolysis is therefore a physiological process within the framework of normal bone remodeling, which reduces bone tissue that is no longer under load and thus adapts it to its functional requirements.
In the context of various diseases, however, osteolysis also has pathological significance. Such is the case with Hajdu-Cheney syndrome. This is an autosomal dominant inherited form of acroosteolysis, also known as familial idiopathic acroosteolysis or hereditary idiopathic osteolysis type VI. The rare hereditary disease locally degenerates the bone tissue.
Only about 50 cases have been reported worldwide since it was first described. Due to the small number of cases, the syndrome has not yet been conclusively researched. This is especially true for the etiology. The US radiologist William Cheney first described the syndrome in a Michigan family in the 20th century. The Hungarian-British radiologist Hajdu described the syndrome a short time later and, together with Cheney, gave the disease its name.
Causes
The cause of Hajdu-Cheney syndrome is suspected to lie in genetic material. Scientists assume a mutation that affects the activity of bone resorption. It is not yet clear which genes mutate as part of the syndrome. In addition to the symptom of progressive bone loss, patients with Hajdu-Cheney syndrome usually have severe short stature.
The mutated gene thus not only causes misguided bone resorption, but apparently a fundamentally defective structure of the bones. Familial accumulation could be observed in the previously documented cases. Family history suggests an autosomal dominant inheritance for the disease.
In the family of the first description, the mother and four of her children showed symptoms of acroosteolysis, a majority of Worm’s bones and hypoplasia of the mandible. Despite the clear family connections of the first description, cases of spontaneous new mutations have also been documented. Thus, in addition to the endogenous factors, exogenous factors are probably also relevant for the pathogenesis. Which exogenous factors could cause new mutations is still unclear.
Symptoms, Ailments & Signs
Hajdu-Cheney syndrome manifests as short stature associated with progressive loss of the phalanges and the crowded metacarpal bones. The sutures of the skull show no ossification. The frontal sinus is not created.
There is also an extension of the Turkish saddle. As the disease progresses, the basilar artery becomes more compressed. This compression can result in a life-threatening condition. The ears of those affected usually show exceptionally large earlobes. In addition, the ears are one level lower than usual. In addition, a particularly broad nose catches the eye.
Over time, the alveolar processes gradually degrade, which explains the early loss of teeth in the patient. During the course of the disease, osteopenia causes scoliosis in the sense of a curvature of the spine. These main symptoms are usually associated with accompanying symptoms. Some of those affected show kidney symptoms such as cystic kidneys in addition to bone symptoms.
Other organ systems can also be affected by the disease. In addition to congenital heart defects, hydrocephalus in the sense of a hydrocephalus can also be present. The liver and spleen can also be enlarged. Cleft palate has also been documented in some cases. The general condition of the patients is characterized by feelings of weakness. Broken bones are the order of the day.
Diagnosis & History
The first signs of Hajdu-Cheney syndrome usually do not manifest themselves in childhood. In many cases, the diagnosis is not made until adolescence. The main early symptoms are pain in the hands. The family history plays a major role in the diagnosis, since in most cases an autosomal dominant inheritance forms the background of the disease.
If Hajdu-Cheney syndrome is suspected, the doctor usually orders a bone density measurement in the sense of an osteodensitometry. This procedure provides evidence of the extreme bone loss. Since no causative gene has been identified to date, molecular genetic studies to detect the disease make little sense.
Nevertheless, they can be arranged for research purposes. The prognosis for patients with Hajdu-Cheney syndrome depends on the time of diagnosis and on the accompanying symptoms.
Complications
As a result of Hajdu-Cheney syndrome, the affected person suffers from various diseases, which usually affect the growth of the bones and thus the entire body. In most cases, short stature occurs. This malformation can lead to teasing or bullying, especially in children.
Furthermore, various bones are compressed, which can result in life-threatening conditions. The position of the ears is also unusual, but this does not lead to hearing problems. Furthermore, patients often suffer from kidney problems and heart defects.
In the worst case, the affected person can suffer cardiac death and die as a result of the heart defect. The spleen and liver are also enlarged and can displace or squeeze other organs inside the body. It is not uncommon for a cleft palate to appear, which makes everyday life difficult for the person concerned. Bone fractures continue to occur very quickly.
No causal treatment of Hajdu-Cheney syndrome is possible. For this reason, the pain is treated primarily, whereby there are no further complications. The patient’s life expectancy is reduced by Hajdu-Cheney syndrome. It is not uncommon for the child’s parents or relatives to suffer from psychological problems and need appropriate care.
When should you go to the doctor?
Hajdu-Cheney Syndrome cannot be completely treated because it is a genetic disease, so causal therapy is not possible. However, a doctor should still be consulted regularly so that there are no further complications for the patient. A visit to the doctor is necessary if the patient suffers from short stature and various malformations on the body. Degradation of the finger bones can also indicate Hajdu-Cheney syndrome and should be investigated.
Furthermore, very large earlobes also indicate the syndrome. In some cases, the disease is associated with skin problems, which should also be examined by a doctor. Examinations of the internal organs are also advisable, since kidney problems or heart defects can often occur. The spleen and liver should also be examined regularly. Since Hajdu-Cheney syndrome can also lead to severe psychological problems in relatives or parents, a visit to a psychologist is also advisable.
Treatment & Therapy
So far, the Hajdu-Cheney syndrome has only been superficially researched. Since only 50 cases have been documented so far, the general research situation is below average. Due to the very limited number of cases, no standardized treatment options exist to date. The onset of osteoporosis can be counteracted with the administration of bisphosphonates.
Causal treatment options do not exist because the cause of the disease corresponds to a genetic mutation. Such a mutation cannot be reversed. Furthermore, because the causative gene has not even been identified, no causal treatment could be developed even with the approval of gene therapy treatment approaches.
Against this background, the patients are treated purely symptomatically. This treatment can include the supportive administration of painkillers for severe pain in the bones. Special therapeutic measures are to be taken in patients with additional heart or kidney symptoms. In these cases, invasive treatment steps are required.
In addition, those affected must be regularly examined for compression of the vessels in order to identify life-threatening conditions in good time. Surgical interventions to free compressed vessels are mandatory.
Outlook & Forecast
The long-term prognosis of Hajdu-Cheney syndrome in terms of life expectancy is not entirely clear, as not much empirical data is available. It is an extremely rare genetic disease that is usually inherited in an autosomal dominant manner. A total of only 50 cases have been reported worldwide so far. The underlying gene defect is unknown. It is also suspected that many cases are due to new mutations and are therefore sporadic.
The disease is rarely diagnosed in childhood. The first signs are often severe pain in the hands caused by severe bone degradation (osteoporosis). Osteoporosis, which occurs early, can be treated well with bisphosphonates. However, the sutures of the skull do not ossify, the frontal sinus is missing and the sella turcica (Turkish saddle) is lengthened.
Overall, as the disease progresses, this can lead to compression of an artery in the brain (basilar artery), which often ends fatally. In a few cases, cystic kidneys, congenital heart defects, cleft palate, hydrocephalus or enlargement of the liver and spleen were observed. These additional symptoms also have a significant impact on the life expectancy of those affected.
Eventually fatal renal insufficiency or cardiac insufficiency can develop in the course of life. Prenatal and neonatal deaths are also likely due to the occasional occurrence of hydrocephalus. Above all, the quality of life of the patients is severely restricted due to their physical weakness and frequent fractures.
Prevention
Preventive measures for Hajdu-Cheney syndrome do not yet exist due to the limited research situation.
Aftercare
Since there are currently no standardized treatment options for Hajdu-Cheney syndrome and all those affected are treated purely symptomatically, there is also no uniform aftercare plan. This also depends on the symptoms present and the therapies prescribed by the doctor.
However, regular check-ups of the vessels with regard to possible compressions are extremely important for all patients. Thanks to these controls, life-threatening conditions can be identified and compressed vessels can be treated surgically. Unfortunately, as the disease progresses, cardiac insufficiency or renal insufficiency can develop.
Early symptoms of the latter are excessive thirst and frequent urination. Tiredness, loss of appetite, reduced performance, shortness of breath or water retention, on the other hand, would be an indication of the onset of cardiac insufficiency. In both cases, a doctor must be contacted immediately. Even without symptoms, regular blood tests for heart failure biomarkers, urea and creatinine are just as important for early detection as urine tests and heart diagnostics using an ECG.
In addition to drug therapy, patients also have access to acupuncture, aromatherapy, and natural remedies. However, due to possible interactions, the latter may only be taken after prior consultation with the doctor treating you. Zinc and omega-3 fatty acids help with bone and joint pain, as well as rest and bed rest in acute cases. A change in diet to raw food and lean meat combined with dietary supplements can also have a supportive effect.
You can do that yourself
There are a few things that people who have been diagnosed with Hajdu-Cheney syndrome can do to support treatment. In consultation with the doctor, natural remedies can be used.
The natural remedies comfrey, St. John’s wort and astaxanthin, for example, help with severe joint pain. Homeopathy offers preparations with African devil’s claw and frankincense, which have a pain-relieving effect and prevent inflammation in the joints and bones. Omega-3 fatty acids and zinc are also proven remedies for bone and joint pain. If symptoms or unusual symptoms appear as a result of ingestion, the responsible doctor must be informed.
Furthermore, Hajdu-Cheney syndrome can be treated with lifestyle changes. The doctor will usually suggest a raw food and lean meat diet, often combined with supplements and avoidance of stimulants such as alcohol and nicotine.
Rest and bed rest help with acute bone pain. The patient can cool the painful areas with a quark or cabbage wrap or massage them. Methods from Chinese medicine as well as acupuncture and aromatherapy can also help against chronic pain.
Since the disease can take a severe course despite all measures, psychological therapy should be used in addition to medical treatment.
