Beckwith-Wiedemann syndrome is a genetic overgrowth disorder usually present at birth and characterized by an increased risk of childhood cancer and certain congenital features. Five common features used to define Beckwith–Wiedemann syndrome are macroglossia, macrosimia, midline abdominal wall defects, ear creases or ear pits, and low blood sugar at birth.
It occurs all over the globe, without any gender bias in all ethnic groups, at the rate of 1 in 14,000 births. The figure may be an under estimate, because the mild cases of Beckwith–Wiedemann syndrome go undetected. About 300 children with Beckwith–Wiedemann syndrome are reportedly born each year in United States. The exact number of Beckwith–Wiedemann syndrome cases is unknown because of the marked variability in the syndrome’s diagnosis. More than 85% cases of BWS are not inherited and occur by chance, without a family history. Scientists believe that BWS and isolated hemihypertrophy are the manifestations of alterations in the expression of one or more genes in children.
Beckwith–Wiedemann syndrome symptoms
Subjects suffering from Beckwith–Wiedemann syndrome, generally have the following special features:
- Defects in abdominal wall, such as umbilical hernia and omphalocele
- Low blood sugar levels at birth
- More weight at birth
- Overgrowth of one side of body parts/organs
- Enlarged tongue and prominent eyes
- Increased risk of developing cancer
- Creases or pits in ear lobe and low-set ears
- Undescended testicles
- Poor feeding
- Enlargement of the organs present in the abdomen such as the liver, pancreas and kidneys
- A ridge in forehead due to premature bone closure
- Enlarged fontanelle
- Isolated hemihypertrophy: It is an over growth of one side of body parts, in comparison to the other portion. The hemihypertrophy is termed as isolated as it occurs by itself, or along with one of the many characteristics of Beckwith–Wiedemann syndrome, or another genetic syndrome. It becomes apparent when the children grow.
Causes of Beckwith–Wiedemann syndrome
Beckwith–Wiedemann syndrome is known as a sporadic condition, as it occurs by chance due to genetic disorders in chromosome 11. It is believed by the scientists that the over growth in this syndrome and hemihypertrophy is caused by the improper inactivation of growth suppressing genes, or due to the over expression of the genes, responsible for growth. The genetic defect not pass on to the children as the mutation is of sporadic nature and hence Beckwith–Wiedemann syndrome is considered as not being a hereditary disorder.
Ten to fifteen percent of Beckwith–Wiedemann syndrome and hemihypertrophy cases are hereditary, and parents can pass on this syndrome to the future generations. The chance of inheritance in this case is 50%, from the affected parent during pregnancy. The translocations and inversions caused by the different types of abnormalities on the same chromosome, can interrupt the genetic functions, and result in Beckwith–Wiedemann syndrome or hemihypertrophy.
Genetic testing for Beckwith–Wiedemann syndrome
Genetic testing will help to confirm and diagnose the presence of Beckwith–Wiedemann syndrome or isolated hemihypertrophy, and its cause. It will be able to identify, how the abnormalities occur within a family and also give the information regarding the chances of reoccurrence in other children. Blood samples are collected for performing the genetic tests. But the genetic tests can’t be considered as final, because among the many causes, some have still remained unsolved.
Treatment for Beckwith–Wiedemann syndrome
Mostly all the children affected by Beckwith–Wiedemann syndrome and isolated hemihypertrophy have normal growth as healthy adults. Their growth tends to normalize the risk and fear for cancer. Also they have normal intelligence, grow normal as any other child, hold normal career, bear healthy children and have a normal life span with a fulfilling life.
If the visible symptoms of Beckwith–Wiedemann syndrome such as enlarged tongue and leg-width disparity, if any, exist, then they can be corrected by surgery. However most of the signs of the disorder vanish along with the progress of age.
One may consult the orthopedist for the child with a long leg or an abnormal tongue. Surgery may be performed if required.
The children with Beckwith–Wiedemann syndrome or hemihypertrophy, mostly develop two types of cancers, i.e. Wilms’ cancer and Hepatoblastoma. Wilms’ cancer is a cancer of kidney, which develops at the age between 5 and 8 years old. Hepatoblastoma is a cancer of liver, which tends to occur at a less frequency as compared to Wilms’ cancer, and which develops at the age of 2 years old.
Both the cancers can be removed by surgery and the cure depends on the stage and the condition of its spread. The subjects with Beckwith–Wiedemann syndrome and isolated hemihypertrophy should have regular screening for detection of potential cancers at the early stage for better outcomes. It will be easier to remove when the cancers are smaller and the results will be better. An early detection would help to avoid chemotherapy, eliminate the need for radiation treatment and the administration of doses also would be lower.
The different types of cancer screening protocol include:
- Abdominal ultrasound examination: Every 3 months up to the age of 8 years. Up to the age of 4 years, the ultrasound test should include liver, kidney and other internal organs.
- Blood test: Should be performed every 6 weeks, up to 4 years, to measure the serum AFP, as it is released by hepatoblastoma cancers.
Beckwith Wiedemann Syndrome pictures