Below is a summary for the PHF21A gene observed in research publications. This is not meant to take the place of medical advice. Click HERE for the full gene guide, which includes more information, such as chance of having another child with this condition, or specialists to consider for people with this condition.
What is PHF21A-Related Syndrome?
PHF21A-related syndrome happens when there are changes to the PHF21A gene. These changes can keep the gene from working as it should.
The PHF21A gene helps to control other genes and is important for the development of the brain.
Because the PHF21A gene is important in brain development, many people who have PHF21A-related syndrome have:
- Intellectual disability
- Increased weight, height, head size
Some people are missing a large segment of DNA that includes the PHF21A gene. This is called Potocki-Shaffer syndrome or 11p11.2-related syndrome, because the missing segment is on part of chromosome 11. Other people have a small change within the PHF21A gene itself. People who have these different syndromes have symptoms that overlap.
Do people who have PHF21A-related syndrome look different?
People who have PHF21A-related syndrome may look different. One study of four people who have the syndrome found that two had flat foreheads and two had large heads.
How many people have PHF21A-related syndrome?
As of 2019, doctors had found fewer than 10 people in the world with changes in just the PHF21A gene. Potocki-Shaffer syndrome is more common, but also very rare. In Potocki-Shaffer syndrome, people are missing a large segment of DNA that includes PHF21A. The first case of PHF21A-related syndrome was described in 2012. Scientists expect to find more people who have the syndrome as access to genetic testing improves.
SPEECH & LEARNING
4 out of 4 had a speech delay.
4 out of 4 had some degree of intellectual disability.
1 out of 3 had autism.
1 out of 3 seem to require lots of sleep.
3 out of 3 had larger than average weight, height, and head size.
MOTOR ISSUES and BRAIN
3 out of 4 had low muscle tone. 1 out of 4 had seizures.
Research Article Summaries