What is ABCC8-related Hyperinsulinism?

ABCC8-related hyperinsulinism, also called congenital hyperinsulinism, is an inherited condition in which the pancreas releases inappropriately large quantities of the hormone insulin, leading to low blood sugar (hypoglycemia). When blood sugar drops to dangerously low levels, seizures and permanent brain damage may occur. If untreated, the condition could ultimately be fatal.

ABCC8 refers to the name of the gene that causes this disease. Other genes have been identified which also cause hyperinsulinism.

The pancreas normally secretes insulin in response to rising blood sugar. In people with ABCC8-related hyperinsulinism, the pancreas secretes insulin even without sugar consumption, thereby removing too much sugar from the blood.

Infants with ABCC8-related hyperinsulinism tend to have significantly low blood sugar within the first few days of life. They often require immediate infusions of the sugar glucose to prevent seizures. These newborns are typically born larger than normal and may show difficulty feeding, poor muscle tone, and breathing problems.

In some people with ABCC8-related hyperinsulinism, symptoms do not appear until later in childhood. The low blood sugar associated with the condition can also range from mild to severe depending on the individual, and varies even among members of the same family. Early and aggressive treatment is important to avoid permanent brain damage.

How common is ABCC8-related Hyperinsulinism?

ABCC8-related hyperinsulinism affects roughly 1 in 50,000 Europeans. It is particularly common among people of Finnish and Saudi Arabian descent, where the disease may affect as many as 1 in 2,500. A certain genetic mutation is prevalent in people of Ashkenazi Jewish descent.

How is ABCC8-related Hyperinsulinism treated?

Treatments for ABCC8-related hyperinsulinism include dietary modification, medications, and surgical intervention. The aim of treatment is to keep the affected person’s blood sugar level in the normal range to avoid brain damage.

If a child shows symptoms of ABCC8-related hyperinsulinism at birth, intravenous glucose is often given to raise and stabilize the blood sugar level. Babies may need frequent feedings with large amounts of carbohydrates, even overnight. A feeding tube may be helpful to ensure that a child gets sufficient quantities of carbohydrates and may facilitate automatic feedings overnight.

There are several types of medication to treat ABCC8-related hyperinsulinism. These are typically taken orally and/or injected several times daily.

When diet and medication do not sufficiently manage blood sugar levels, the person may require surgery to remove part of the pancreas.

After an extended period of successful treatment, many people with ABCC8-related hyperinsulinism find their symptoms lessen in severity or even go into remission.

People with ABCC8-related hyperinsulinism may find their symptoms aggravated by viral infections and should take particular precautions when they become ill, even if their symptoms have gone into remission. They should also avoid long periods of time without eating.

What is the prognosis for a person with ABCC8-related Hyperinsulinism?

The long-term outlook for someone with ABCC8-related hyperinsulinism depends upon the severity of the symptoms and the vigilance of the efforts to treat it. Permanent brain damage can occur from episodes of low blood sugar. Even with treatment, people with the disease can develop some degree of brain damage or have learning difficulties. They also may be at an elevated risk of diabetes. In the most serious cases, when the disease is not recognized and properly treated, it can be fatal. However with careful treatment, people with ABCC8-related hyperinsulinism can live normal lifespans.

Resources

• Children’s Hospital of Philadelphia Congenital Hyperinsulinism Center
  A center within the Children’s Hospital of Philadelphia that specializes in the treatment of hyperinsulinism in children.
  The Children’s Hospital of Philadelphia Division of Endocrinology/Diabetes
  3516 Civic Center Blvd., Suite 802
  Philadelphia, PA 19104-4318
  Phone: 215-590-7682
  [email protected]
• Congenital Hyperinsulinism International
  A non-profit dedicated to improving the lives of children, adults, and families living with congenital hyperinsulinism.
  5 Sierra Blanca Rd.
  Cedar Crest, NM 87008
  [email protected]
• Congenitalhikids.org
  Charity whose mission is to increase awareness of Congenital Hyperinsulinism among the public and medical personnel across the United States.
• Sur1.org
  A website by and for parents of children with hyperinsulinism meant to share stories and information. Please note that SUR1 is another name for the ABCC8 gene.
  [email protected]

Other names for ABCC8-related Hyperinsulinism

• Persistent Hyperinsulinemic Hypoglycemia of Infancy
• Familial Hyperinsulinism with Pancreatic Nesidioblastosis
• Familial Hyperinsulinemic Hypoglycemia 1
• Hyperinsulinemic Hypoglycemia of Infancy
• Nesidioblastosis of Pancreas
• Hyperinsulinemic Hypoglycemia Due to Focal Adenomatous Hyperplasia
• HHF1
• Congenital Hyperinsulinism
• ABCC8-Related Hyperinsulinism
• Familial Hyperinsulinism

Take action now to assess your risk for ABCC8-related Hyperinsulinism and your risk for passing it to your children. To get started with a JScreen genetic test, click here.

Source: Counsyl.