What Is Nephrotic Syndrome, NPHS1-Related?
NPHS-1 related nephrotic syndrome is an inherited condition in which the kidneys leak proteins into the urine due to an abnormality in a protein called nephrin. Symptoms of the disease begin in the first days or weeks after birth, but always before the age of three months. The disease occurs mainly in people of Finnish origin, and another name for this disease is congenital Finnish nephrosis (CNF). NPHS-1 related nephrotic syndrome is often fatal by the age of five, and many cases are fatal within the first year. If the child survives to the age of two or three, kidney transplantation may allow for a more normal lifespan. NPHS-1 related nephrotic syndrome is caused by mutations in the NPHS1 gene.
Children with NPHS-1 related nephrotic syndrome are often born prematurely with low birth weight. Low levels of protein in the blood, combined with kidney failure, cause the whole body to swell with excess fluids (edema). These children have a poor appetite and urinate less frequently than children without the disease. Children with congenital NPHS-1 related nephrotic syndrome have difficulty getting needed nutrients and may not grow as large as they would otherwise. Fat levels in the blood may also be high.
People with nephrotic syndrome associated with loss of protein into the urine cannot retain sufficient amounts of antibodies that help the body fight infection. As a result, they are more prone to infection. They are also prone to potentially harmful blood clots.
How Common Is Nephrotic Syndrome, NPHS1-Related?
NPHS-1 related nephrotic syndrome has an incidence of 1 in 8,000 in Finland. The worldwide incidence of nephrotic syndrome is 1 to 3 in 100,000. Approximately 7% of nephrotic syndrome is caused by mutations in NPHS1. The incidence is 1 in 500 in children born in the Old Order Mennonite population in Lancaster County, Pennsylvania.
How Is Nephrotic Syndrome, NPHS1-Related Treated?
Because NPHS-1 related nephrotic syndrome is often fatal in infancy, early and vigilant treatment is necessary to allow the child to live until the age of two or three when a kidney transplant is feasible. This is the only hope for a normal lifespan. The disease does not affect the new kidney, but in about 20% of transplantations the body develops antibodies to the nephrin protein and high levels of protein in the blood can return.
A physician may recommend infusions of protein for children with nephrotic syndrome associated with protein loss. Diuretic drugs may be prescribed to help eliminate excess water and thus eliminate some swelling. Antibiotics will be necessary to control infection. If the disease is too severe, the child's kidneys may need to be removed before he or she is old enough for a transplant. Dialysis machines can be used as a stopgap measure to filter wastes from the child's blood until a transplant can be completed.
Some children with NPHS-1 related nephrotic syndrome have abnormal thyroid activity and may require hormone replacement. Others have a tendency towards blood clots and may benefit from a blood thinner. Good nutrition is key to growth. Those who cannot eat sufficient quantities may need a feeding tube.
What Is the Prognosis for a Person with Nephrotic Syndrome, NPHS1-Related?
Many cases of NPHS-1 related nephrotic syndrome are fatal within five years. If children with severe symptoms live until the age of two or three, an early kidney transplant may help them live a more normal lifespan. While children with NPHS-1 related nephrotic syndrome typically experience kidney failure by ages two to eight, with treatment, some may not experience kidney failure until adolescence or adulthood.