The newborn baby in the intensive care unit is exhibiting symptoms of Harlequin Ichthyosis including severe ectoropion, cracking skin forming diamond shaped plates, and near immobility. Harlequin Ichthyosis is an extremely rare genetic condition caused by a mutation in the ABCA12 gene, which is important for lipid transport in skin cells. This results in improper skin development, making the baby vulnerable to infection and dehydration with restricted movement. While most babies do not survive past infancy, testing such as ultrasound and genetic testing can detect the condition prenatally.

1. A Case Study
By: William Larson

2. The Mystery
• A newborn baby is lying in the intensive care unit shortly after birth.
She is exhibiting severe ectoropion (eyelid turned outwardly from the
eyeball) along with extreme cracking of her outermost layer of skin
into diamond shaped plates that are separated by deep fissures. She
is nearly immobile as a result of the armor like plates, and is not
expected to live more that a few weeks at best.

3. What is your diagnosis for
the newborn baby?

4. What tests would you
administer to confirm your
diagnosis?

5. Harlequin Ichthyosis
• Is an extremely rare genetic condition that results in improper
development of skin cells that renders the baby vulnerable to
infection, dehydration, and extremely restricted movement.
• It is so infrequent that the rate of occurrence is unknown.
• Generally fatal, with many babies dying before, or shortly after birth.
Less than a handful of people have survived to adulthood with the
condition.

6. Pictured left is a newborn that has severe Harlequin
Ichthyosis. Pictured right is Hunter Steinitz, one of the few
patients to survive to adulthood with the condition.

7. Testing for the condition
• Generally this condition does not require testing beyond it’s telltale
symptoms, but it can be detected prior to birth by Ultrasound, or by
genetic testing to determine of the gene responsible for the condition
is mutated.

8. Harlequin Ichthyosis Causes
• Harlequin Ichthyosis is caused by a mutation in the ABCA12 gene. This
gene is responsible for making ATP-binding cassette (ABC) transporter
which is important for moving lipids into the cells that form the
epidermis.
• Some mutations of the gene are more severe than others. Some
mutations can result in a complete inability to transport any lipids,
while others form a smaller version of the protein that cannot
transport lipids properly.

9. On the right normal protein function is depicted. On the left the diagram
shows what happens in Harlequin Ichthyosis patients

10. Treatment Options
• There are currently no known cures for Harlequin Ichthyosis, but for
those rare few that survive past infancy, management is possible.
Patients need to keep their skin moisturized using petroleum based
lotions and stay in humid environments. Regular examinations and
testing need to be done to ensure that they do not become infected
with bacteria.
• In the future, it is not inconceivable to imagine that CRISPR/CAS9
could be used to treat the condition, since it is localized to a single
gene.