What is Congenital Chloride Diarrhea?

Congenital Chloride Diarrhea (CCD) is a rare inherited disorder that affects the way the intestines absorb salt and water. Babies born with this condition have persistent, watery diarrhea containing high levels of chloride, starting shortly after birth.

CCD is a lifelong condition, but with proper treatment and monitoring, many individuals can live healthy lives. If not diagnosed and managed early, CCD can lead to dehydration, electrolyte imbalances, and growth problems.

What Causes CCD?

CCD is caused by mutations in the SLC26A3 gene, which is responsible for producing a protein that helps absorb chloride in the intestines. When this protein doesn’t work properly, the body loses large amounts of chloride, sodium, and water through stool.

It is inherited in an autosomal recessive pattern, meaning both parents must carry one copy of the faulty gene for the child to be affected.

What Are the Symptoms of CCD?

Symptoms usually appear within the first days of life and may include:

• Chronic watery diarrhea (often starting in the newborn period)
• Dehydration
• Weight loss or poor weight gain
• Failure to thrive
• Abdominal bloating or distension
• Muscle weakness or fatigue (due to low potassium and other electrolyte imbalances)
• Alkalosis (a condition where the blood becomes too alkaline)
• Prenatal signs such as excess amniotic fluid (polyhydramnios) or enlarged intestines seen on ultrasound

Despite the diarrhea, the stool may not always look watery because it gets absorbed in the diaper, making the condition easy to overlook.

How is CCD Diagnosed?

CCD is diagnosed through a combination of:

• Stool tests: To measure high chloride levels
• Blood tests: To detect low sodium, potassium, and chloride and signs of metabolic alkalosis
• Genetic testing: To confirm mutations in the SLC26A3 gene
• Prenatal imaging: May raise suspicion if intestinal abnormalities are seen

An accurate diagnosis is crucial for starting the right treatment and avoiding complications.

How is CCD Treated?

There is no cure for CCD, but lifelong management can effectively control the symptoms and prevent complications.

Treatment includes:

• Oral salt supplements: Especially sodium chloride (table salt) and potassium chloride to replace the lost electrolytes
• Plenty of fluids: To prevent dehydration
• Monitoring of growth and electrolytes: Regular check-ups are important
• Nutritional support: Including high-calorie diets in some cases
• Proton pump inhibitors (in some cases): To reduce the loss of chloride through stool

With proper treatment, diarrhea often improves and children can grow and develop normally.

What is the Outlook for People with CCD?

If diagnosed early and managed properly, the prognosis is generally good. Many individuals with CCD lead normal lives, go to school, and participate in regular activities. Delayed or missed diagnosis, however, can lead to serious complications like kidney damage, growth failure, or developmental delays.

Long-term follow-up with a pediatrician or gastroenterologist is usually necessary to ensure ongoing health.

Can CCD Be Prevented?

CCD cannot be prevented once a child inherits two copies of the mutated gene, but genetic counseling can help at-risk families understand their options. If both parents are known carriers, they can consider:

• Carrier testing
• Prenatal genetic testing
• Preimplantation genetic diagnosis (PGD) during IVF

Who is at Risk for CCD?

• Children born to parents who are both carriers of the SLC26A3 gene mutation
• Consanguineous families (parents who are related by blood) have a higher chance of passing on recessive conditions
• Certain populations, including people of Finnish, Arab, or Eastern European descent, may have higher rates of CCD