Causes

Congenital nephrotic syndrome is a very rare form of nephrotic syndrome. It occurs mostly in families of Finnish origin and develops shortly after birth. It is inherited, which means it is passed down through families.

Children with this disorder have an abnormal form of a protein called nephrin. The kidney's filters (glomeruli) need this protein to function normally.

Symptoms

• Cough
• Decreased urine output
• Foamy appearance of urine
• Low birth weight
• Poor appetite
• Swelling (total body)

Exams and Tests

An ultrasound done on the pregnant mother before birth may show a larger-than-normal placenta. The placenta is the organ that develops during pregnancy to feed the growing baby.

Pregnant mothers may have a screening test done during pregnancy to check for this condition. The test looks for higher-than-normal levels of alpha-fetoprotein in a sample of amniotic fluid. Genetic tests should be used to confirm the diagnosis if the screening test is positive.

After birth, the infant will show signs of severe fluid retention and swelling. The health care provider will hear abnormal sounds when listening to the baby's heart and lungs with a stethoscope. Blood pressure may be high. There may be signs of malnutrition.

A urinalysis reveals fat and large amounts of protein in the urine. Total protein in the blood may be low.

Treatment

Early and aggressive treatment is needed to control this disorder.

Treatment may involve:

• Antibiotics to control infections
• Blood pressure medicines called ACE inhibitors and ARBs to reduce the amount of protein leaking into the urine
• Diuretics ("water pills") to remove excess fluid
• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin to reduce the amount of protein leaking into the urine

Fluids may be limited to help control swelling.

The health care provider may recommend removing the kidneys to stop protein loss. This may be followed by dialysis or a kidney transplant.

Outlook (Prognosis)

The disorder often leads to infection, malnutrition, and kidney failure. It can lead to death by age 5, and many children die within the first year. Congenital nephrotic syndrome may be controlled in some cases with early and aggressive treatment, including an early kidney transplant.

Possible Complications

• Acute kidney failure
• Blood clots
• Chronic kidney failure
• End-stage kidney disease
• Frequent, severe infections
• Malnutrition and related diseases

When to Contact a Medical Professional

Call your health care provider if your child has symptoms of congenital nephrotic syndrome.

Alternative Names

Nephrotic syndrome - congenital

References

Nachman PH, Jennette JC, Falk RJ. Primary glomerular disease. In: Brenner BM, ed. Brenner and Rector's the Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 30.

Pais P, Avner ED. Nephrotic syndrome. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, St. Geme JW III, Schor NF, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap. 521.

Updated: 4/20/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Herbert Y. Lin, MD, PhD, Nephrologist, Massachusetts General Hospital; Associate Professor of Medicine, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.