May-Hegglin Anomaly

By | June 8, 2022

May-Hegglin anomaly is an inherited leukocyte abnormality that is one of the MYH9-associated diseases and is associated with a point mutation. The hereditary disease is associated with a lack of platelets and an abnormal platelet shape. Patients with the anomaly therefore suffer from a slight tendency to bleed.

What is a May-Hegglin anomaly?

The group of so-called MYH9-associated diseases includes various hereditary diseases that are based on a mutation in the MYH6 genes. This group of diseases includes the May-Heggelin anomaly, which is associated with altered blood platelets and is included under the genetic leukocyte anomalies. For what is mesiodentes, please visit

Other diseases from the group of MYH9-associated clinical pictures are Sebastian syndrome, Fechtner syndrome and Epstein syndrome. The May-Hegglin anomaly is the most common disease from the larger group, although the anomaly is also a rare disease. So far, not enough cases have been documented to be able to give a reliable prevalence.

The small number of cases makes research on the May-Hegglin anomaly and the other MYH9-associated diseases difficult. For this reason, not all connections of the disease group have been finally clarified.


MHA is caused by a genetic mutation. It is a point mutation in the MYH9 gene located on chromosome 22 and gene locus q11.2. This gene encodes type IIA non-muscle myosin heavy chains. This is a protein that is found primarily in blood cells such as monocytes and thrombocytes, as well as within the cochlea and kidneys.

Mutation of the gene results in a conformational change that affects the head of the NMMHC-IIA protein. The protein of the patients abnormally aggregates into Döhle bodies because of the conformational change, and the cytoskeleton of the megakaryocytes organizes itself incorrectly as a result. Megakaryocytes are precursor cells to platelets.

Thus, the mutation of the gene in the context of the May-Hegglin anomaly not only leads to a leukocyte anomaly, but also to macrothrombocytopenia. This phenomenon is characterized by a lack of platelets, which arises from oversized platelets. The hyperplastic thrombocytes contain leucocyte inclusions and sometimes even become larger than erythrocytes. Familial clustering has been observed for the anomaly. The disease is passed on in an autosomal dominant mode of inheritance.

Symptoms, Ailments & Signs

Patients with the May-Hegglin anomaly suffer from a number of characteristic clinical symptoms. The symptom complex includes a reduced platelet count and altered platelet volume. Due to these connections, they are usually affected by an increased tendency to bleed, since the thrombocytes play a major role in the coagulation cascade.

The symptomatic bleeding tendency of the patients is not as pronounced as in patients with the related Sebastian syndrome. However, patients with May-Hegglin anomaly also suffer from platelet dysfunction, also known as thrombocytopathy. These symptoms are associated with macrothrombocytopenia, which is reflected in the presence of platelets of abnormal size with leukocyte inclusions.

Unlike patients with Fechtner syndrome or Epstein syndrome, those affected do not have any hearing loss or kidney problems. The anomaly is usually referred to as the mildest disease from the range of MYH9-associated diseases because it is associated with the fewest symptoms and the mildest expression.

Diagnosis & disease progression

Diagnosing a May-Hegglin anomaly can be challenging for the doctor. Some patients hardly show any symptoms and are therefore not diagnosed at all or only at an older age. Because there are almost no symptoms, the medical history often does not get the doctor very far. Abnormalities are often not discovered until routine blood tests are performed.

On closer examination, these can suggest a disease from the group of MYH9-associated diseases. In order to differentiate between the diseases in this group, a molecular genetic analysis must be carried out. Although all four diseases from the group express themselves as point mutations of the MYH9 gene, these point mutations are localized at different sites depending on the disease.

For this reason, a clear diagnosis of the anomaly can be made through the DNA analysis. The prognosis is extremely favorable. As a rule, there are no restrictions on life expectancy or everyday life for those affected.


Patients with the May-Hegglin anomaly experience increased bleeding. These occur even with minor injuries or cuts and are in most cases very difficult to stop. The quality of life of those affected is significantly restricted and reduced by the May-Hegglin anomaly. In some cases, the May-Hegglin anomaly can also lead to hearing loss and thus to further limitations in the patient’s everyday life.

Kidney problems also occur, so that in the worst case the affected person can suffer from kidney failure. Those affected depend on regular examinations and checks in order to avoid various consequential damages. Unfortunately, a direct and causal treatment of the May-Hegglin anomaly is not possible. The treatment is therefore primarily aimed at reducing the symptoms.

However, in many cases, no treatment is necessary for the May-Hegglin anomaly if there is no damage or limitations to the internal organs. Those affected have to watch out for various dangers in their everyday life and avoid them so that bleeding does not occur. In acute emergencies, the bleeding can be stopped with medication. In most cases, life expectancy is not reduced by the May-Hegglin anomaly.

When should you go to the doctor?

People who show an increased tendency to bleed in direct comparison to their fellow human beings should consult a doctor. If even small wounds can only be stopped with great effort or after a large loss of blood, a doctor’s visit is advisable. In addition, sterile wound care is required so that there is no threat of sepsis and thus a risk to life. If the wound care cannot be guaranteed to the extent required by the person concerned, a doctor must be consulted as soon as possible. If existing wounds tear again very quickly when the dressing is changed, this is a sign of an existing irregularity. This significantly disrupts an optimal healing process and should be examined by a doctor.

If the person concerned suffers from frequent nose or gum bleeding, it is advisable to discuss the observations with a doctor. If there is dizziness, blurred vision, or loss of internal strength due to increased blood loss, a doctor is needed. Extensive investigations are necessary so that a cause can be determined and a diagnosis made possible. In the event of a loss of consciousness, an emergency service must be alerted. A potentially life-threatening condition exists that requires medical attention. If sexually mature women suffer from heavy menstrual bleeding, they should record the amount of blood and then consult a doctor. Hearing loss also requires a doctor.

Treatment & Therapy

A causal therapy is not available for any of the MYH9-associated diseases. The May-Hegglin anomaly has also been considered incurable due to its genetic basis. Gene therapy therapy steps are currently an object of medical research. For this reason, in the near future, there may be a causal treatment for the abnormality that will make the disease a curable disease.

So far this is still a dream of the future. Symptomatic treatments can be given to patients with the May-Hegglin anomaly as needed. In most cases, however, therapy is not necessary. Most of those affected are hardly affected at all by the disease. Even with minor injuries, the disease usually does not lead to serious complications or unacceptably high blood loss, since the bleeding tendency of the patient is limited.

In the context of serious injuries and operations, patients are usually given a platelet concentrate to compensate for the platelet deficiency and promote clotting. Bleeding complications can be prevented in this way.

Outlook & Forecast

The prognosis in terms of life expectancy is positive for almost all patients with the May-Hegglin anomaly. The mutation-related hereditary disease has become known as the most common of the very rare MYH9-associated diseases.

The May-Hegglin anomaly can be kept stable with symptomatic therapy. A platelet transfusion is only necessary before an upcoming operation. Only operational and postoperative risks can worsen the prognosis. The fact that the prognosis for the May-Hegglin anomaly is so favorable is a stroke of luck. However, those affected suffer from an increased tendency to bleed due to this disease. However, this is not comparable to hemophilia. It turns out to be significantly weaker.

There are usually no other symptoms. This form of MYH9-associated diseases can therefore be clearly distinguished from the other forms in this group. The problem, however, is that some patients with this anomaly have no symptoms at all. For this reason, some people only become conspicuous at an advanced age. Without a molecular genetic examination or a DNA analysis, the doctor will not be able to determine which of the four diseases in this group is present.

So far, only a few cases of the May-Hegglin anomaly have occurred. So far no statements can be made about the prevalence of the anomaly. Doctors only know that the May-Hegglin anomaly is inherited in an autosomal dominant manner. It therefore tends to run in families. Since the prognosis is favorable, no life-limiting consequences of the disease are to be expected.


The diseases from the group of MYH9-associated diseases are all extremely rare diseases. Because of this, research within the disease group is not advanced enough for preventive measures to be available. Because of the hereditary nature of the May-Hegglin anomaly, patients with this disease can at least seek genetic counseling during family planning.


The May-Hegglin anomaly is usually associated with various ailments, all of which can have a very negative impact on the life and quality of life of the person affected. Therefore, the affected person should contact a doctor as soon as the first symptoms or signs of the disease appear so that the symptoms do not continue to worsen.

Due to the increased tendency to bleed, sufferers should be careful to lead a mindful lifestyle to reduce the risk of injury. If the symptoms of the disease have promoted the development of psychological problems or even depression, a psychologist should be consulted. Accompanying therapy can help to restore mental balance and promote better management of the disease.

You can do that yourself

Since those affected suffer from a significantly increased tendency to bleed due to the May-Hegglin anomaly, any bleeding must be avoided. This also includes avoiding dangerous sports or accidents. The attending physician should always be informed about the May-Hegglin anomaly even during surgical interventions or various other medical examinations.

If both parents suffer from this anomaly, genetic counseling can be useful if you wish to have children. The risk of inheritance of this disease can be estimated. If the patient starts bleeding, it must be stopped. In most cases, you do not need to see a doctor, but it may take a little longer for the bleeding to stop. Large blood losses do not occur and there are no further complications.

In the case of surgical interventions, patients are dependent on taking medication to avoid heavy bleeding. Further treatment of the May-Hegglin anomaly is not necessary. In most cases, the development of the child is not negatively affected by the disease, so that no treatment is necessary here either.

May-Hegglin Anomaly