Chronic Granulomatous Disease
Description
Chronic granulomatous disease (CGD) is a rare genetic disorder that affects the immune system‘s ability to fight certain types of infections. People with CGD have a weakened immune system, making them susceptible to severe and recurrent infections, primarily caused by bacteria and fungi. This blog provides a comprehensive overview of CGD, exploring its causes, symptoms, diagnosis, management, and strategies for living a fulfilling life despite the challenges.
Genes Involved
CGD is caused by mutations in genes responsible for producing enzymes that are essential for the proper functioning of white blood cells called neutrophils. These enzymes help neutrophils kill bacteria and fungi. The genes involved in CGD include:
- CYBB (gp91-phox): The most common gene affected in CGD, accounting for approximately 65% of cases.
- CYBA (p22-phox): This gene is responsible for about 10-15% of CGD cases.
- NCF1 (p47-phox): Mutations in this gene account for around 10% of cases.
- NCF2 (p67-phox): Mutations in this gene are responsible for about 5% of cases.
- NCF4 (p40-phox): The least common gene involved, accounting for less than 5% of cases.
Recognizing the Signs and Symptoms
Recognizing the signs and symptoms of CGD is crucial for early diagnosis and intervention. Common symptoms include:
- Recurrent bacterial and fungal infections: Frequent ear infections, pneumonia, skin abscesses, and bone infections are characteristic of CGD.
- Granulomas: These are small, inflamed lumps that can form in various organs due to the body‘s inability to effectively clear infections.
- Delayed wound healing: Wounds may take longer to heal in people with CGD.
- Chronic inflammation: Persistent inflammation can lead to complications in different organs.
- Growth delays: In some cases, children with CGD may experience slower growth compared to their peers.
Causes
CGD is caused by mutations in genes responsible for producing enzymes essential for the proper function of white blood cells called neutrophils. These enzymes help neutrophils kill bacteria and fungi. When these genes are mutated, neutrophils cannot effectively fight off certain infections, leading to the symptoms of CGD.
Inheritance/recurrence risk
CGD is an inherited disorder, meaning it is passed down from parents to their children. Most cases are inherited in an X-linked recessive pattern. This means that a male child will inherit CGD if his mother carries the faulty gene. Females are less likely to develop CGD because they have two X chromosomes, and one healthy copy of the gene can compensate for the mutated one. However, females can still be carriers and pass the gene on to their children. There is also a rare autosomal recessive form of CGD, where two copies of the faulty gene are needed for an individual to develop the disorder. This means both parents must carry the mutated gene for their child to inherit CGD.
Recurrence risk: The risk of having another child with CGD depends on the inheritance pattern and the parents‘ genetic status. Genetic counseling can help families understand the risk and make informed decisions about family planning.
