kell blood group system Flashcards
syllabus based
What chromosome is the KEL gene located on, and what is its primary function?
The KEL gene is located on chromosome 7q33. Its primary function is to encode the Kell protein, which presents various Kell antigens on the surface of red blood cells.
How does the KEL gene contribute to the polymorphism observed in the Kell blood group system?
The KEL gene is highly polymorphic, meaning it has a lot of genetic variation. This results in the presence of over 25 different Kell antigens, with K and k being the most common and clinically significant.
Explain the relationship between the Kell protein and the XK protein.
The Kell protein is linked to the XK protein, which is encoded by the XK gene on the X chromosome. The XK protein acts as a transporter and is essential for the proper expression of Kell antigens. Mutations in the XK gene can lead to the McLeod phenotype, characterized by weakened Kell antigen expression and neurological symptoms.
Describe the inheritance pattern of the Kell antigens.
The Kell antigens follow an autosomal codominant inheritance pattern. This means that each person inherits one allele from each parent, and both alleles are expressed in the phenotype. For example, someone with Kk genotype will express both K and k antigens.
What is the clinical significance of the McLeod phenotype in the context of the Kell blood group system?
The McLeod phenotype arises from mutations in the XK gene, leading to reduced Kell antigen expression and associated neurological and muscular symptoms. Clinically, individuals with the McLeod phenotype can experience chronic granulomatous disease and are at risk of developing hemolytic transfusion reactions due to altered red blood cell antigens.
What chromosome is the KEL gene located on, and what is its primary function?
The KEL gene is located on chromosome 7q33. Its primary function is to encode the Kell protein, which presents various Kell antigens on the surface of red blood cells.
Discuss the potential genetic mutations in the KEL gene and their effects on Kell antigen expression.
Genetic mutations in the KEL gene can lead to either loss or altered expression of Kell antigens. Such mutations can cause variants like K0 (Knull), where no Kell antigens are expressed, leading to increased susceptibility to hemolytic transfusion reactions and hemolytic disease of the newborn if antibodies are present.
Why is the Kell blood group system particularly significant in transfusion medicine and prenatal care?
The Kell blood group system is significant due to the strong immunogenicity of Kell antigens. Antibodies against these antigens can cause severe hemolytic transfusion reactions and hemolytic disease of the newborn. Accurate blood typing and monitoring for Kell antibodies are essential to prevent these complications.
How does the KEL gene contribute to the polymorphism observed in the Kell blood group system?
The KEL gene is highly polymorphic, meaning it has a lot of genetic variation. This results in the presence of over 25 different Kell antigens, with K and k being the most common and clinically significant.
Explain the relationship between the Kell protein and the XK protein.
The Kell protein is linked to the XK protein, which is encoded by the XK gene on the X chromosome. The XK protein acts as a transporter and is essential for the proper expression of Kell antigens. Mutations in the XK gene can lead to the McLeod phenotype, characterized by weakened Kell antigen expression and neurological symptoms.
Describe the inheritance pattern of the Kell antigens.
The Kell antigens follow an autosomal codominant inheritance pattern. This means that each person inherits one allele from each parent, and both alleles are expressed in the phenotype. For example, someone with Kk genotype will express both K and k antigens.
What is the clinical significance of the McLeod phenotype in the context of the Kell blood group system?
The McLeod phenotype arises from mutations in the XK gene, leading to reduced Kell antigen expression and associated neurological and muscular symptoms. Clinically, individuals with the McLeod phenotype can experience chronic granulomatous disease and are at risk of developing hemolytic transfusion reactions due to altered red blood cell antigens.
How does the polymorphism of the KEL gene impact blood transfusion compatibility?
The polymorphism of the KEL gene results in diverse Kell antigens, which necessitates precise blood typing and crossmatching to ensure transfusion compatibility. Antibodies against Kell antigens, particularly anti-K, can cause severe hemolytic transfusion reactions, making accurate matching crucial.
