From the start of this month, following an application by the RCPA, four new items for genetic testing will be introduced to the Medicare Benefits Schedule (MBS) which will allow individuals to determine their carrier status for alpha thalassaemia. Dr Ellen Maxwell is Director of Haematology and Medical Director at Melbourne Pathology Services and was involved in the application to the Medical Services Advisory Committee (MSAC).

“Alpha thalassemia is an inherited blood disorder which involves genetic changes in the alpha globin genes HBA1 and HBA2. Normally, everyone has two copies of each of these genes; one copy of each from each parent. Mutations or deletions of these genes can cause alpha thalassaemia. People who have this condition don’t make as much normal alpha globin, which can lead to anaemia and other medical problems. The severity of the disease can vary from clinically silent to significant, requiring transfusion support.

“Severity can be predicted by the number of genes affected. One gene loss potentially causes no demonstrable change to the patient or their blood tests, hence the term “silent”. Two or more deletions make an individual’s red cells progressively smaller and increase the degree of anaemia. Haemoglobin H (HbH) disease occurs when both parents carry abnormalities. It causes moderate to severe anaemia and is the result of three affected genes. The most severe type, Hb Bart’s, is due to four gene deletions. It is almost uniformly lethal for fetuses and is associated with high maternal morbidity. These latter conditions are what we are trying to predict and prevent.

“The addition of these new MBS items will allow at-risk individuals of reproductive age, and their reproductive partners, to access genetic tests to determine their carrier status for alpha thalassemia. It is suggested that all couples thought to be at risk should be tested before starting a family. We can determine who is at risk through a specific blood test and by looking at family history and ethnicity. In our multicultural society, it is more complex, and assumptions should never be made, particularly based on name alone.

“The first assessment should be haemoglobin studies, a full blood examination and iron studies. The need to proceed to further genetic testing in those considered to be likely carriers can be determined by the screening laboratory. It is important to understand that alpha thalassaemia can occur alone, or in combination with other haemoglobin disorders that are common in our community, including with beta thalassaemia (up to 10% have both) and the common South-East Asian beta globin variant, Haemoglobin E,” said Dr Maxwell.

Services supported under the new MBS items, in combination with appropriate counselling, will provide some couples with reassurance, and for others support the pursuit of reproductive options or inform planning for those with a high-risk pregnancy.

The items, which are currently supported under funding arrangements that differ across states and territories, better ensure equity of access, and minimise out-of-pocket payments for genetic testing for alpha thalassaemia.