What is Wolf-Hirschhorn Syndrome?

It can be very hard to learn that your child has Wolf-Hirschhorn syndrome, also known as 4p- syndrome. Naturally, you have a lot of questions about what caused it and how it can be treated.

Wolf-Hirschhorn is a rare genetic disorder that your baby gets when part of chromosome 4 is deleted. It happens when cells divide abnormally during reproduction.

When any part of a chromosome is missing, it can damage normal development. The deleted chromosome 4 causes the features of Wolf-Hirschhorn, including facial features like wide-set eyes, a distinct bump on the forehead, a broad nose, and low-set ears.

Each case is different, because the amount of symptoms depends on how much of the chromosome is deleted.

What Causes It?

Doctors don’t really know what causes this spontaneous genetic change that occurs during a baby’s development. The “broken” chromosome usually isn’t inherited from either parent; the deletion typically occurs after fertilization. Doctors do think that three different genes can be deleted from chromosome 4, and all are important to early development.

Each missing gene causes a separate set of the condition’s symptoms. For example, one is linked to abnormalities of the face, while another seems to trigger the seizures that affect nearly all children with Wolf-Hirschhorn.

Sometimes though, Wolf-Hirschhorn syndrome is caused when one of the parents has something called a “balanced translocation.” That mean two or more of their chromosomes broke and switched spots during their development. It usually doesn’t cause any symptoms in that parent since the chromosomes are still balanced. But it raises the odds that person will have a child with a chromosomal disorder, including Wolf- Hirschhorn.

You can get a genetic test to see if you have balanced translocation.

What Are the Symptoms?

Wolf-Hirschhorn affects many parts of the body, both physical and mental. The most common symptoms are abnormalities of the face, delayed development, intellectual disabilities, and seizures.

Other problems your baby could have include:

• Bulging, wide-set eyes
• Droopy eyelids and other eye problems
• Cleft lip or palate
• Downturned mouth
• Low birth weight
• Microcephaly, or an unusually small head
• Underdeveloped muscles
• Scoliosis
• Heart and kidney problems
• Failure to thrive

How Is It Diagnosed?

Sometimes your doctor can find the physical signs of Wolf-Hirschhorn syndrome with routine ultrasounds during your first trimester of pregnancy. Or chromosome issues could show up in what’s known as an expanded cell-free DNA screening test. But these are both just screenings, not diagnostic tests. Your doctor will need to do more tests to know whether your baby has Wolf-Hirschhorn.

One test that can detect more than 95% of chromosome deletions in Wolf- Hirschhorn is called a “fluorescence in situ hybridization” (FISH) test. Tests done after your baby is born also can identify the partial deletion of the chromosome.

If your doctor confirms your child has Wolf-Hirschhorn, they may suggest several imaging tests to fully understand all affected areas of your baby’s body. You and your partner also should be tested if you plan to have more children in the future.

How Is It Treated?

There is no cure for Wolf-Hirschhorn syndrome, and every patient is unique, so treatment plans are tailored to manage the symptoms. Most plans will include:

• Physical or occupational therapy
• Surgery to repair defects
• Support through social services
• Genetic counseling
• Special education
• Controlling seizures
• Drug therapy

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