Jacobsen Syndrome: Information and Causes

Achievement Center of Texas' Jacobsen Syndrome Center makes sure to provide physical and emotional support to those that have Jacobsen Syndrome. Jacobsen syndrome is a condition caused by a loss or deletion of several genes from chromosome 11. It is also known as 11q terminal deletion disorder because this deletion occurs at the end of the long (q) arm of chromosome 11.

The size of the deletion differs among affected people, but the deleted area almost always includes the tip of chromosome 11.The specific features of Jacobsen syndrome relate to the deletion of multiple genes within the deleted region. As with WHS (Wolf-Hirschhorn Syndrome), larger deletions cause more severe signs and symptoms than smaller deletions.

In about 85% of cases, the deletion is due to a de novo deletion, a random error during the formation of the egg or sperm, or an error in cell division in early fetal development. In about 15% of cases, the deletion is caused by a parent having a balanced translocation or from other, rare types of chromosome rearrangements.

Achievement Center of Texas Jacobsen Syndrome Center
Via Wikimedia Commons

Symptoms/Characteristics of Jacobsen Syndrome

 The signs and symptoms of Jacobsen syndrome can vary.


  • Small and low-set ears
  • Wide-set eyes
  • Droopy eyelids
  • Skin folds covering inner corner of eyes
  • Broad nasal bridge
  • Down-turned corners of mouth
  • Thin upper lip
  • Small lower jaw
  • Large head
  • Skull abnormality
  • Bleeding disorder (Paris-Trousseau Syndrome)
  • Short stature


  • Heart Defects
  • Feeding difficulties in infancy
  • Frequent ear and sinus infections
  • Issues with digestive system, kidneys, and genitalia
  • Delayed development of motor skills and speech
  • Cognitive (mind) impairment
  • Learning difficulties
  • Short attention span
  • ADHD (Attention deficit hyperactivity disorder)

***more information on characteristics and symptoms are found here.

How ACT Helps Those with Jacobsen Syndrome

There is no cure for Jacobsen syndrome. However, there is treatment that generally focuses on the specific signs and symptoms that are present in each individual. It will require the coordinated efforts of a team of various specialists.

With there being no cure for JS, it may seem as though there is no hope. But, support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. This, in turn, makes hope. Many organizations also have experts that serve as medical advisors or provide lists of doctors/clinics.

As always, living with a genetic or rare disease can impact the daily lives of patients and families. You as a loved one and we as a facility all work as a unit to ensure that the loved one feels wanted and motivated to live an impactful long life.