Is congenital enzyme deficiency hereditary?

Enzymes are needed to carry out activities and participate in our bodies. If our body lacks enzymes, it will affect the normal functioning of the body. So, is congenital enzyme deficiency hereditary? In fact, generally speaking, no. However, anemia caused by enzyme deficiency is a hereditary phenomenon, so if you have hereditary enzyme deficiency, you should be alert to anemia.

Studies have found that there are more than 40 enzymes involved in red blood cell metabolism. If a genetic defect occurs, the activity of certain enzymes will be reduced, thereby affecting the metabolism and function of red blood cells and causing hemolytic anemia.

Cause disease

Studies have found that there are more than 40 enzymes involved in red blood cell metabolism. If a genetic defect occurs, the activity of certain enzymes will be reduced, thereby affecting the metabolism and function of red blood cells and causing hemolytic anemia. Nearly 20 enzymes that cause hemolytic anemia have been found, which can be divided into three categories:

① Enzymes in the direct glucose glycolysis pathway (EMP): hexokinase (HK), phosphoglucose isomerase (PGI), phosphofructokinase (PFK), aldolase (ALD), triosephosphate isomerase (TPI), phosphoglyceraldehyde dehydrogenase (PGD), diphosphoglycerate mutase (DPGM), phosphoglycerate kinase (PGK), pyruvate kinase (PK), adenosine triphosphatase (ATPase);

② Enzymes in the hexose phosphate shunt (HMP): glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-R), γ-glutamylcysteine ​​synthetase (γ-GC-Syn), glutathione synthetase (GSHSyn), adenylate kinase (AK);

③ Non-glycolytic enzymes: pyrimidine 5' nucleotidase (P5'Nase) and adenosine deaminase (AD).

Anemia caused by the above-mentioned red blood cell enzyme deficiency is rare in clinical practice. However, the incidence of glucose-6-phosphate dehydrogenase (G6PD) deficiency is very high and is prevalent among all ethnic groups in the world. In addition, pyruvate kinase (PK) deficiency is also common.

Hemolytic anemia

Hemolytic anemia caused by red blood cell enzyme deficiency was originally called congenital non-spherocytic hemolytic anemia and is now called hereditary non-spherocytic hemolytic anemia (HNHA). Based on the results of the autolysis test, this anemia is divided into type I and type II. In the autohemolysis test, red blood cells undergo hemolysis after incubation in the patient's own serum. If glucose or ATP is added first, the hemolysis can be partially corrected, which is type I. If the hemolysis cannot be corrected by glucose but can be partially corrected by ATP, it is HNHA type II. Type I is caused by enzyme defects in the hexose phosphate shunt (HMP), with glucose-6-phosphate dehydrogenase (G6PD) deficiency being the most common; Type II is caused by enzyme defects in the direct glycolysis (EMP) pathway, represented by pyruvate kinase (PK) deficiency.

HNHA type I is a rare type of G6PD deficiency. It is known that more than 80 of the more than 220 variants of G6PD can cause HNHA, in which the G6PD activity in red blood cells is extremely deficient or completely absent. Patients often have chronic hemolytic anemia since infancy or childhood, and sometimes have jaundice at birth. Hemolysis can be aggravated by fever, infection, or medication, but in most cases there are no obvious predisposing factors. Splenomegaly is common. The degree of hemolysis and anemia is generally mild to moderate. There were no spherocytes and the osmotic fragility of red blood cells was normal. The reticulocyte count is often elevated. People with mild anemia do not need special treatment, but people with severe anemia often need blood transfusions. Although the spleen is enlarged, splenectomy has no obvious therapeutic effect and can only occasionally alleviate anemia.