The cause of Beckwith-Wiedemann syndrome is unknown, but it appears to be genetic. Some cases may be associated with a defect in chromosome number 11.

Affected children are often large at birth. Many have an abdominal wall defect, such as an umbilical hernia or omphalocele. They have a characteristic facial appearance with a gaping mouth and large tongue.

Infancy can be a critical period because of low blood sugar (hypoglycemia), omphalocele (when present), and an increased rate of tumor development (Wilm's tumor and adrenal carcinoma being most common).

• Large newborn (LGA, large for gestational age)
• Large tongue, sometimes protruding
• Large prominent eyes
• Creases in ear lobes
• Pinna abnormalities and low set ears
• Abdominal wall defect: umbilical hernia or omphalocele
• Separated abdominal muscles (diastasis recti)
• Undescended testicles (cryptorchidism)
• Low blood sugar (hypoglycemia)
• Poor feeding
• Lethargy
• Seizures
• Enlargement of some organs and tissues

The signs for Beckwith-Wiedemann syndrome are as follows:

• Hypoglycemia (low blood sugar)
• Enlarged kidneys, liver, and spleen
• Large fontanelle (enlarged soft spot)
• Metopic ridge (a ridge in the forehead, caused by premature closure of the cranial suture just forward of anterior fontanelle)
• Early bone maturation
• Accelerated growth (in the 90^th percentile)

The tests for Beckwith-Wiedemann syndrome are as follows:

• Bone X-ray (of the long bones)
• Blood tests to test for low sugar or other abnormalities
• Ultrasound of the abdomen
• X-ray of the abdomen
• MRI scan of the abdomen or CT scan of the abdomen
• Chromosome studies (for abnormalities in the chromosome 11)

In infancy, hypoglycemia may be treated with intravenous solutions. Enlargement of the tongue can cause problems with feeding and sleeping. Defects of the abdominal wall may need to be repaired. In addition, affected children must be followed carefully for the appearance of tumors.

A support group for this syndrome can be found at http://www.beckwith-wiedemann.org/www.beckwith-wiedemann.org. Another useful site is the Beckwith-Wiedemann Syndrome Family Forum (http://www.geocities.com/beckwith_wiedemannwww.geocities.com/beckwith_wiedemann), which is associated with an online discussion group (http://groups.yahoo.com/group/bwschat/groups.yahoo.com/group/bwschat).

Children who survive infancy do well, although there is no long-term follow-up information available. Mental function appears to be normal to very slightly decreased.

• Hypoglycemia
• Seizures
• Respiratory difficulties from obstruction due to large tongue
• Feeding problems
• Development of tumors

If you have a child with Beckwith-Wiedemann syndrome at home, any worrisome symptoms develop, call your health care provider immediately.

There is no known prevention at this time. Genetic counseling may be of value for families.