Patients with CD55-deficiency usually start exhibiting symptoms between ages 1-3 years. The clinical presentation of the disorder is mostly gastrointestinal and includes:
- Intestinal protein loss (protein-losing enteropathy) causing low albumin (hypoalbuminemia) and total protein (hypoproteinemia)
- Peripheral and/or generalized edema
- Diarrhea, vomiting, distended abdomen and abdominal pain
- Anemia, vitamin and micronutrient deficiencies
- Malnutrition and poor growth
- Susceptibility to clot formation
- Complications of CD55-deficiency may include repeat intussusceptions, abdominal obstruction, and intestinal failure
Protein-losing enteropathy (low serum albumin, edema, diarrhea) is the main feature observed in CD55-deficiency patients, but not all patients exhibit all disease characteristics. Patients may also appear generally healthy or present only with mildly low serum albumin, with or without edema and diarrhea. Other gastrointestinal diagnoses, such as inflammatory bowel disease (IBD), have also been associated with CD55-deficiency.