Congenital diaphragmatic hernia
Congenital diaphragmatic hernia is a birth defect where an opening in the diaphragm allows abdominal organs to move into the chest, potentially crowding the lungs and heart.
Overview
The diaphragm is a muscle that separates the abdomen from the chest. A congenital diaphragmatic hernia occurs when the diaphragm does not develop correctly before birth, ranging from a thinned area to a complete absence of the muscle. This opening allows organs like the stomach and intestines to move into the chest cavity, which can lead to pulmonary hypoplasia (underdevelopment of the lungs) and severe breathing difficulties at birth.
Types of Hernia
- Bochdalek hernia: A defect in the side or back of the diaphragm; accounts for 80–90% of cases.
- Morgagni hernia: A defect in the front part of the diaphragm; accounts for approximately 2% of cases and is less likely to cause severe symptoms at birth.
- Rare types: Defects in the central region or complete absence of the muscle.
Causes
The cause of congenital diaphragmatic hernia is often unknown, though it is classified in several ways:
- Syndromic: In 10–15% of cases, it is part of a larger syndrome (e.g., Donnai-Barrow, Fryns, or Pallister-Killian mosaic syndrome).
- Associated Abnormalities: About 25% of non-syndromic cases involve abnormalities in other body systems, such as the heart, brain, or kidneys.
- Isolated: 50–60% of cases are isolated, meaning there are no other major malformations.
- Genetic Factors: Researchers are studying transcription factors and genes involved in cell structure and migration as potential causes.
Inheritance
Isolated congenital diaphragmatic hernia is rarely inherited, and in almost all cases, only one individual in a family is affected. When the hernia is part of a genetic syndrome or chromosomal abnormality, it may follow the inheritance pattern associated with that specific condition.
