Vel blood group

Human blood group system

Vel blood group

The Vel blood group is a rare human blood group system. It is characterized by the presence or absence of the Vel antigen on the surface of red blood cells. The Vel antigen is a high-prevalence antigen, meaning it is present in the majority of the population. However, individuals who lack the Vel antigen can produce anti-Vel antibodies, which can lead to complications in blood transfusions.

Discovery

The Vel blood group was first identified in 1952 when a patient experienced a severe hemolytic transfusion reaction. Subsequent research revealed that the reaction was due to the presence of anti-Vel antibodies in the patient's blood, which attacked the transfused red blood cells that carried the Vel antigen.

Genetic basis

The Vel blood group is determined by the presence of the SMIM1 gene, which encodes a small membrane protein. Individuals who are Vel-negative have a deletion in the SMIM1 gene, resulting in the absence of the Vel antigen on their red blood cells. The inheritance pattern of the Vel blood group is autosomal recessive, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to be Vel-negative.

Diagram showing autosomal recessive inheritance.

Clinical significance

The presence of anti-Vel antibodies can cause hemolytic transfusion reactions in Vel-negative individuals who receive blood from Vel-positive donors. These reactions can be severe and life-threatening. Therefore, it is crucial to identify Vel-negative individuals and provide them with Vel-negative blood for transfusions.

Blood donation

Due to the rarity of Vel-negative blood, there is a need for Vel-negative individuals to donate blood. Blood banks often maintain a registry of Vel-negative donors to ensure a supply of compatible blood for patients who require it.

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Blood donation at a mobile blood donation unit.

Related pages

• Blood group system
• Blood transfusion
• Hemolytic disease of the newborn