Fast Facts: Pyruvate Kinase Deficiency for Patients and Supporters: A rare genetic disease that affects red blood cells

By R. Grace

Pyruvate kinase deficiency is a rare genetic disease that causes red blood cells to break apart. Despite an ever-growing understanding of the disease, it remains unfamiliar to many healthcare professionals, and the information available to patients is limited. This superbly illustrated workbook is designed to help patients equip themselves with the best information about their condition to improve the conversations they have about it with their doctors and nurses. Contents: • What is pyruvate kinase deficiency? • What causes PK deficiency? • How is PK deficiency diagnosed? • How will PK deficiency affect me or my child? • Treating PK deficiency • What sort of monitoring might I need? • Special situations • When should I see my doctor? • What can I do to help myself?

• Language: English
• Publisher: S. Karger
• Release date: Feb 6, 2019
• ISBN: 9781910797921

Book preview

What is pyruvate kinase deficiency?

Pyruvate kinase (PK) deficiency is a rare genetic disease that affects red blood cells. Everyone who has PK deficiency is born with it, even if they are diagnosed later in life. To understand how PK deficiency affects you, you need an understanding of the role of healthy red blood cells and pyruvate kinase, and what happens to red blood cells in PK deficiency.

The role of red blood cells

Red blood cells have a flexible shape called a biconcave disc, which looks like a flattened sphere. This flexible shape allows the cells to squeeze through narrow blood vessels (capillaries) as they deliver oxygen to the body. Healthy red blood cells can squeeze through the smallest capillaries.

The role of pyruvate kinase

Red blood cells make energy by converting glucose (a sugar) into pyruvate (an important molecule in metabolism) and a high-energy molecule called adenosine triphosphate (ATP) in a multistep process called glycolysis.

Pyruvate kinase is an enzyme that makes the last step in this process happen. It converts a protein called phosphoenolpyruvate into pyruvate and ATP. Less pyruvate kinase results in less ATP, so red blood cells have less energy.

The energy generated by glycolysis helps healthy red blood cells to keep their normal shape, stay flexible and protect themselves from injury (oxidative damage). In people with a normal amount of pyruvate kinase, red blood cells can generate enough ATP to last an average of 120 days.

The breakdown of red blood cells

The breakdown of red blood cells is called hemolysis. Normally, after 120 days, red blood cells break down and are removed from the circulation by the spleen.

Red blood cells that do not have enough pyruvate kinase cannot make enough energy to hold their shape, and they break apart more easily than healthy red blood cells. Instead of lasting 120 days, PK-deficient red blood cells only last a few days to weeks.

The breakdown of red blood cells (hemolysis) causes hemolytic anemia (a low red blood cell count or low hemoglobin level) and jaundice