Login

GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY (G6PD)

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic disorder caused due to a defect in an enzyme called glucose-6-phosphate dehydrogenase that causes red blood cells to break down prematurely.

G6PD is an enzyme that protects the red blood cells from damage and destruction by harmful and toxic compounds that form in the body under certain conditions like stress, fever, or following the ingestion of certain foods or drugs. The enzyme generates compounds that can neutralize the toxic compounds formed in the body.

Causes of G6PD

It is an X-linked disorder that may be inherited from mother (usually a healthy carrier) or affected father to son or daughter. G6PD cannot be spread from one person to another. [1]

Sign and Symptoms of G6PD

People with G6PD deficiency do not display any signs of the disease until they are exposed to certain chemicals in food or drugs whereby their RBC being broken down in excess.

Other symptoms:

  • Sudden rise of body temperature
  • Dark yellow-orange urine
  • Weak and rapid pulse rate.

It is common for babies to have jaundice (yellowing of the skin and eyes) in the first week of life, but some babies with G6PD deficiency have jaundice for longer than usual.

Diagnosis of G6PD

  • Blood tests

Blood tests may reveal low red blood cell count, increased bilirubin levels, and increased plasma hemoglobin levels. Other blood tests may confirm presence of intravascular hemolysis. However, the blood tests may be normal between the attacks.

  • Blood film examination

Examination of a stained blood film under the microscope may show abnormal broken red cells (hemolytic RBCs). Special stains show denatured hemoglobin within red cells (Heinz bodies) and increased immature red cells (reticulocytes) due to formation of new red cells (erythropoiesis) by the bone marrow as compensatory response. If the abnormal cells have the appearance of a bitten piece they are termed bite cells.

  • Urine tests

The urine specimen during the attack is dark colored and positive for hemoglobin and hemosiderin

  • Screening tests to detect low G6PD levels

Several screening tests are available that demonstrate the decreased capacity of G6PD deficient cells to reduce dyes. The enzyme can also be directly assayed.

Drugs to Avoid

Foods and Chemical to Avoid

  • Fava Beans (broad beans)
  • Red wine
  • Henna dyes used for tattoo & Hair
  • Blueberries [also yogurts containing these]
  • Soya products
  • Tonic water
  • Naphthalene (moth balls)

References:

  1. The Royal Children’s Hospital Melbourne. (n.d.). Retrieved from https://www.rch.org.au/kidsinfo/fact_sheets/g6pd_deficiency/
  2. Schick P. (Dec 2018) Glucose-6-Phosphate Dehydrogenase Deficiency. Medscape. Available from http://emedicine.medscape.com/article/200390- overview.
  3. MIMS 158th Edition Sep 2019 Malaysia. Drugs and Other Substances to Avoid in G6PD Deficiency. Pg 174-177