Alpha Thalassemia Trait



Alpha thalassemia is common in people of African, Southern Chinese, Southeast Asian, Middle Eastern and Mediterranean descent.


What is Alpha Thalassemia?

Alpha thalassemia genes can mix in different ways; this can range from the loss of one alpha thalassemia gene to the loss of four alpha thalassemia genes. Based on the number of alpha thalassemia gene(s) a person is missing, the different outcomes are listed below:


What is Bart’s Hemoglobin on the newborn screening test?

A new baby with Bart’s hemoglobin on the newborn screening means that alpha gene deletions are present, and the baby might have alpha thalassemia, alpha thalassemia trait, or hydrops fetalis.

Alpha thalassemia can cause low red blood cell levels (mild anemia) and should not be confused with not having enough iron in the blood.

Tell the doctor if your child’s newborn screening test showed Bart’s hemoglobin.


What is Alpha Thalassemia trait?

There are two different types of alpha thalassemia trait.

  1. The first type of alpha thalassemia trait has one alpha gene missing on each chromosome (α-/α-). This is called the trans form of alpha thalassemia trait.
  1. The second type of alpha thalassemia trait has two missing alpha genes on the same chromosome (αα/--). This is called the cis form of alpha thalassemia trait.
  2. Both types of alpha thalassemia trait are common in people of Southeast Asian, Southern Chinese, Mediterranean and Middle Eastern descent, however, the cis type of trait is more common.

People with alpha thalassemia trait do not develop Hemoglobin H cell disease or Hydrops Fetalis later in life.


Why is it important to know if I have Alpha Thalassemia trait?

 

What if one parent has Alpha Thalassemia trait and the other parent is a silent carrier?

If one parent has the cis form of alpha thalassemia trait (αα/--), and the other parent is a silent carrier (αα/α-), there is a 25 percent (1 in 4) chance with each pregnancy of having a child with Hemoglobin H disease.

Hemoglobin H disease is lifelong illness that can result in serious health problems and requires treatment by a physician

 

What if both parents have the cis form of Alpha Thalassemia trait?