Congenital Amegakaryocytic Thrombocytopenia

Gene : MPL

What is Congenital Amegakaryocytic Thrombocytopenia?

Congenital Amegakaryocytic Thrombocytopenia (CAMT) is an inherited bone marrow failure disorder that begins in infancy. In this disease, the blood producing cells in the bone marrow do not produce platelets, which are important for blood clotting, or megakaryocytes, which are responsible for producing platelets. This means the child's blood will not clot properly after bleeding. Over time, the bone marrow may stop making red blood cells and neutrophils. The symptoms for CAMT, such as bruising and bleeding, can be life threatening. Intellect is not affected by CAMT. Currently, the only treatment for CAMT is bone marrow transplantation. CAMT is caused by pathogenic variants in the MPL gene.

How is Congenital Amegakaryocytic Thrombocytopenia inherited?

CAMT is inherited in an autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

What does it mean to be a carrier?

There are generally no signs or symptoms associated with being a carrier for CAMT. However, the risk to have a child affected with CAMT is increased. Testing of reproductive partners is recommended for carriers of CAMT.

How common is Congenital Amegakaryocytic Thrombocytopenia?

CAMT is a very rare genetic condition and it is unknown how often it occurs. Only a limited number of cases have been reported since the initial report of this disease.

Family References and Resources
Clinician References
What is Analyzed?
  • Full gene sequencing
Affected Systems


Carrier Rates
Detection Rate
Carrier Frequency
Ashkenazi Jewish > 99% 1 in 75
General Population > 99% 1 in 500

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