Overview of Jacobsen Syndrome
Jacobsen syndrome is a major inborn condition. It causes
mental retardation and multiple birth defects.
The syndrome occurs when genetic material is missing from
chromosome 11. This can affect over 340 genes critical to the normal bodily development.
Jacobsen syndrome is very rare. It affects only 1 in 100,000
About twice as many females are born with the syndrome as males
In most cases, the condition isn’t inherited. It is caused by a mistake during
reproductive cell division when a baby is being formed in the womb.
Jacobsen syndrome causes a wide range of symptoms and
Many infants born with Jacobsen syndrome have central
nervous system (CNS) defects.
These can affect how the brain and spinal cord function. The
result is impaired intelligence, learning, speech, and motor skills (NICHD).
Affected children can have problems speaking, walking, standing,
and sitting normally. Later, behavioral problems can occur. The most common issues
- compulsive behavior
- short attention span
- easily distracted
Children with Jacobsen syndrome are often diagnosed with attention deficit hyperactivity disorder
Congenital Defects and Common Illnesses
Short build and skull abnormalities also occur. These
include a large-sized head, called macrocephaly,
or pointed forehead, called trigonocephaly.
Other common facial deformities include:
- wide-set eyes (hypertelorism)
- droopy eyelids (ptosis)
- skin covering the inner corners of the eyes
- broad nasal bridge
- V-shaped mouth
- small lower jaw
- small low-set ears, rotated backwards
Over 90 percent of affected newborns have a bleeding
disorder called Paris-Trousseau syndrome
This prevents blood from clotting, and causes excessive bleeding and easy
Other common issues include:
- heart defects and congenital heart disease
- kidney defects
- gastrointestinal abnormalities
- eating difficulties and failure to thrive
- otitis media, frequent ear infections,
sinusitis, and recurrent respiratory infections
- genitalia abnormalities
Newborns with Jacobsen syndrome may have trouble eating.
Often, they need to be fed through a tube. These babies have problems gaining
weight and growing normally.
Eyesight, hearing, immune system, and hormonal anomalies can
also affect children with Jacobsen syndrome.
How Is it Diagnosed?
Diagnosis usually occurs at birth or in early childhood. Facial
dysmorphism and blood platelet dysfunction are distinctive signs of the
Doctors can conduct blood tests, auditory tests, and endocrine
and immunological assessments. A chromosome test called cytogenetic analysis confirms diagnosis.
Prenatal diagnosis is also possible with cytogenetic
analysis. This involves taking a sample of amniotic fluid or chorionic villus.
These samples are taken from the placenta of a pregnant mother. However, there
is some risk of miscarriage (NIH).
How Is it Treated?
There is no cure for Jacobsen syndrome. But treatments can
help with some symptoms.
Care for newborns usually requires specialists, including:
- pediatric cardiologists
- orthopedic specialists
Surgeries may be needed to repair malformations, including
gastrointestinal corrections. Major cardiac defects can require heart surgery
Because there is a bigger risk of bacterial infection of the
heart lining and valves with heart surgery, antibiotics may be needed with
heart surgery (ORDR).
Blood or platelet problems should be monitored frequently. Transfusions
may be necessary with any surgery. Respiratory, sinus, and ear infections should
be aggressively treated early. Eye defects may be improved with glasses,
contact lenses, or eye surgery. Abnormalities in joints, tendons, muscles, and
bones may be treated by orthopedic techniques. These can potentially be in
combination with surgery. Physical therapy may help improve coordination and
Delayed development treatments include physical, speech, and
occupational therapy. Special education classes and psychological counseling
can help with learning and behavior management.
Early interventions are important to help affected children
reach their full potential.
What Is the Outlook for Children With Jacobsen Syndrome?
About 20 percent of infants with Jacobsen syndrome die by
age 2. Early death is most commonly due to heart problems, and less commonly
due to bleeding (INSERM).
The life expectancy of people with Jacobsen syndrome isn’t
known, but some individuals have lived into adulthood.