Question: What is (are) Pyruvate kinase deficiency ?
Answer: Pyruvate kinase deficiency is a genetic blood disorder characterized by low levels of an enzyme called pyruvate kinase, which is used by red blood cells. Without pyruvate kinase, red blood cells break down too easily, resulting in low levels of these cells (hemolytic anemia). The signs and symptoms of the disease may vary greatly from person to person. However, they usually include jaundice, enlargement of the spleen, and mild or severe hemolysis (red cell breakdown), leading to anemia. In some cases, the problems may first appear while in utero, causing a condition in which abnormal amounts of fluid build up in two or more body areas of the fetus (hydrops fetalis). Newborns may present with 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 the anemia tends to stabilize in adulthood, episodes of anemia may occur with acute infections, stress, and pregnancy. Pyruvate kinase deficiency is caused by a mutation in the PKLR gene and is inherited in an autosomal recessive fashion. Treatment remains supportive rather than curative.
Source: GARD

Question: What are the symptoms of Pyruvate kinase deficiency ?
Answer: What are the signs and symptoms of Pyruvate kinase deficiency? The signs and symptoms of pyruvate kinase deficiency may vary greatly from person to person, but usually include the breakdown of red blood cells resulting in hemolytic anemia, a yellowing of the whites of the eyes (icterus), fatigue, lethargy, recurrent gallstones, jaundice, and pale skin (pallor). In more severe cases, the first signs and symptoms may appear in utero in the form of hydrops fetalis, a condition in which abnormal amounts of fluid build up in two or more body areas of the fetus. Newborns may present with 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 the anemia tends to stabilize in adulthood, episodes of anemia may occur with acute infections, stress, and pregnancy. The Human Phenotype Ontology provides the following list of signs and symptoms for Pyruvate kinase deficiency. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Intrauterine growth retardation 5% Nonimmune hydrops fetalis 5% Abnormality of the amniotic fluid - Autosomal recessive inheritance - Cholecystitis - Cholelithiasis - Chronic hemolytic anemia - Increased red cell osmotic fragility - Jaundice - Reticulocytosis - Splenomegaly - Unconjugated hyperbilirubinemia - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Pyruvate kinase deficiency ?
Answer: What causes pyruvate kinase deficiency? In most cases, pyruvate kinase deficiency is caused by mutations in the PKLR gene. More than 100 different mutation in the PKLR gene have been detected. Medical conditions, such as acute leukemia, preleukemia, and refractory sideroblastic anemia, as well as complications from chemotherapy, can cause an acquired pyruvate kinase deficiency. This type is more common and milder than the hereditary type.
Source: GARD

Question: Is Pyruvate kinase deficiency inherited ?
Answer: How is pyruvate kinase deficiency inherited? Pyruvate kinase deficiency is inherited in an autosomal recessive fashion, which means that a child must inherit a gene with a disease-causing mutation from both parents to develop the disorder. The gene that causes pyruvate kinase deficiency is called the PKLR gene that is located on chromosome 1q21. Although the inheritance is clinically autosomal recessive, most affected individuals are compound heterozygous for two different mutant alleles. It is estimated that approximatly 1 in 100 people carry one copy of a disease-causing mutation in the PKLR gene. Carriers of one non-working PKLR gene usually have moderatly reduced levels of pyruvate kinase activity but do not develop clinical symptoms. It is possible that carriers of a mutant pyruvate kinase genemay have a protective advantage against malaria in areas where the disease is endemic.
Source: GARD

Question: How to diagnose Pyruvate kinase deficiency ?
Answer: Is genetic testing available for pyruvate kinase deficiency? Yes. GeneTests lists laboratories offering clinical genetic testing for this condition. Clinical genetic tests are ordered to help diagnose an affected person or other family members and to aid in decisions regarding medical care or reproductive issues. We recommend that you talk to your health care provider or a genetic professional to learn more about your testing options.
Source: GARD

Question: What are the treatments for Pyruvate kinase deficiency ?
Answer: How might pyruvate kinase deficiency be treated? Mild cases require no treatment. People with severe anemia may need blood transfusions. In newborns with dangerous levels of jaundice, a health care provider may recommend an exchange transfusion. Surgical removal of the spleen (splenectomy) may also be necessary to help reduce the destruction of red blood cells. However, this does not help in all cases. With small children, this is delayed as long as possible to allow the immune system to mature. Other treatment is symptomatic and supportive. Someone who had a splenectomy should receive the pneumococcal vaccine at recommended intervals. They also should receive preventive antibiotics until age 5. An article from eMedicine Journal provides additional information on treatment for pyruvate kinase deficiency at the following link. You may need to register to view the article, but registration is free. http://emedicine.medscape.com/article/125096-treatment#showall
Source: GARD