تويت
Pyruvate kinase deficiency
Definition
Pyruvate kinase deficiency is an inherited deficiency of the enzyme pyruvate kinase, which is used by red blood cells.
Without this enzyme, red blood cells break down too easily, resulting in low levels of these cells (hemolytic anemia).
Causes
Pyruvate kinase deficiency is transmitted as an autosomal recessive trait,
which means that a child must get the defective gene from both parents to develop the disorder.
There are many different types of enzyme-related defects of the red blood cell that can cause hemolytic anemia.
Pyruvate kinase deficiency is the second most common cause, followingG-6-PD deficiency.
Pyruvate kinase deficiency may produce mild or severe hemolysis (red cell breakdown)
and anemia.
Problems may first appear in the newborn as prolonged jaundice and anemia.
Older children may be pale (due to anemia), and have intermittent episodes of jaundice. Mild cases may escape detection until adulthood.
Although pyruvate kinase deficiency is found in people of all ethnic backgrounds, certain populations, such as the Amish, have a somewhat higher incidence.
Symptoms
A family history of pyruvate kinase deficiency
Pallor
Jaundice
A yellowing of the whites of the eyes (icterus)
Fatigue, lethargy caused by anemia
Recurrent gallstones
Exams and Tests
During a physical exam, the doctor will look for an enlarged spleen.
Tests include the following:
CBC showing anemia with normocytic (normal size) red blood cells
Macrocytosis (large red blood cells)
Pyruvate kinase activity shows deficient levels of this enzyme in red blood cells
High levels of bilirubin in the blood
Low levels of haptoglobin in the blood
Increased osmotic fragility or red blood cells may not be present
High stool urobilinogen
Genetic testing for mutation in the pyruvate kinase gene
Treatment
Blood transfusions may be needed for severe anemia. Removal of the spleen (splenectomy) may help to reduce the destruction of red blood cells; however, this should not necessarily be performed as it does not help in all cases. In newborns with dangerous levels of jaundice, an exchange transfusion is likely to be recommended.
If a splenectomy was done, the person should receive pneumococcal vaccine at recommended intervals, and should receive antibiotic prophylaxis until the age of five.
summary:
Hemolytic Anemia >>>> Hereditary >>> Metabolism >>> PK deficiency
Autosomal recessive
and RBC become rigid as a result of reduced ATP formation
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and RBC become rigid as a result of reduced ATP formation
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Definition
Pyruvate kinase deficiency is an inherited deficiency of the enzyme pyruvate kinase, which is used by red blood cells.
Without this enzyme, red blood cells break down too easily, resulting in low levels of these cells (hemolytic anemia).
Causes
Pyruvate kinase deficiency is transmitted as an autosomal recessive trait,
which means that a child must get the defective gene from both parents to develop the disorder.
There are many different types of enzyme-related defects of the red blood cell that can cause hemolytic anemia.
Pyruvate kinase deficiency is the second most common cause, followingG-6-PD deficiency.
Pyruvate kinase deficiency may produce mild or severe hemolysis (red cell breakdown)
and anemia.
Problems may first appear in the newborn as prolonged jaundice and anemia.
Older children may be pale (due to anemia), and have intermittent episodes of jaundice. Mild cases may escape detection until adulthood.
Although pyruvate kinase deficiency is found in people of all ethnic backgrounds, certain populations, such as the Amish, have a somewhat higher incidence.
Symptoms
A family history of pyruvate kinase deficiency
Pallor
Jaundice
A yellowing of the whites of the eyes (icterus)
Fatigue, lethargy caused by anemia
Recurrent gallstones
Exams and Tests
During a physical exam, the doctor will look for an enlarged spleen.
Tests include the following:
CBC showing anemia with normocytic (normal size) red blood cells
Macrocytosis (large red blood cells)
Pyruvate kinase activity shows deficient levels of this enzyme in red blood cells
High levels of bilirubin in the blood
Low levels of haptoglobin in the blood
Increased osmotic fragility or red blood cells may not be present
High stool urobilinogen
Genetic testing for mutation in the pyruvate kinase gene
Treatment
Blood transfusions may be needed for severe anemia. Removal of the spleen (splenectomy) may help to reduce the destruction of red blood cells; however, this should not necessarily be performed as it does not help in all cases. In newborns with dangerous levels of jaundice, an exchange transfusion is likely to be recommended.
If a splenectomy was done, the person should receive pneumococcal vaccine at recommended intervals, and should receive antibiotic prophylaxis until the age of five.
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