Jacobsen Syndrome is a rare chromosomal disorder that occurs in about 1 of every 100,000 newborns. The condition affects both sexes, but it is more common in girls

The severity of Jacobsen Syndrome varies from person to person, but it significantly affects both physical and mental development. It is also associated with autism and other serious health complications.

What Causes Jacobsen Syndrome?

Jacobsen syndrome occurs when there’s a loss of genetic material on chromosome 11, usually as a result of an entirely random cell division. In the other 10-15% of cases, Jacobsen syndrome is inherited. You don’t have to have Jacobsen syndrome to pass it on to your child. If the genetic  material in your chromosome 11 is rearranged, balanced translocation can occur. This can increase your risk of passing Jacobsen syndrome to your child. 

How is Jacobsen Syndrome Diagnosed?

It’s possible to diagnose Jacobsen syndrome in the womb, during your pregnancy. If your general practitioner or OB/GYN discovers anything abnormal during an ultrasound, they might recommend a non-invasive prenatal test. To do this, your doctor draws a sample of your blood and sends it to a laboratory for further testing. 

Once your general practitioner or OB/GYN receives the results of your genetic test, they can refer you to a genetic counselor who can better explain the results of the test.

What Are the Symptoms of Jacobsen Syndrome?

Jacobsen syndrome presents a range of symptoms that often begin in the womb, one of the first being slow growth. Other physical signs of Jacobsen syndrome that develop after birth include:

  • A broad nasal bridge
  • A thin upper lip
  • A small lower jaw
  • Small, low set ears
  • Wide-set eyes
  • Droopy eyelids

Many people with Jacobsen syndrome also have some form of cognitive impairment. Usually, this affects speech and motor skills, resulting in mild to severe learning disabilities.

Jacobsen syndrome also presents behavioral symptoms. For example, many children with the condition exhibit compulsive behavior, short attention spans, and easy distractibility. It also occurs comorbidly with ADHD and autism. 

Children with Jacobsen syndrome are also more likely to experience serious health issues including:

  • Learning disabilities
  • Bleeding disorders
  • Heart conditions 
  • Kidney problems 
  • Gastrointestinal disorders

Many children with Jacobsen syndrome can experience eye problems and immunodeficiency. This makes them more susceptible to ailments like the common cold, flu, ear infections, and sinus infections.

What Can I Do if I Find Out My Child May Have Jacobsen Syndrome?

Learning your unborn child might have Jacobsen syndrome can cause many questions to arise. The disorder is rare and presents a risk of serious health problems. If you have questions or concerns, don’t hesitate to bring them up with your general practitioner, OB/GYN, or genetic counselor. 

Groups like Chromosome Disorder Outreach or the 11q research & resource group are organizations that regularly share news and information about Jacobsen syndrome and Jacobsen syndrome research. They also provide a platform where parents and family members can connect, share stories with one another, and offer support.