Symptoms

Studies into the impacts of KDM5C variants on humans only began relatively recently. However, it is already clear that symptoms are on a spectrum in terms of type and severity.

Clinical Manifestations Survey

In February 2020, researchers from the Albert Einstein College of Medicine conducted the first formal survey of the clinical manifestations associated with variants in the gene KDM5C. You can watch presentations about the results here. An academic paper based on the survey is available here.

RARE-X

In October 2024, RARE-X published this summary of symptoms reported by 43 respondents who have participated in its KDM5C Data Collection Program.

DECIPHER Database

The Wellcome Sanger Institute publishes a list of phenotypes present in multiple matching KDM5C patients who participated in the Deciphering Developmental Disabilities study.

Anecdotal reports

A review of posts to the KDM5C Support Group Facebook group (conducted in 2020) identified the following symptoms:

Reported by almost everyone

• Learning disability / global developmental delay
• Speech delay / oral dyspraxia
• Short stature
• Challenging behaviour
• Strabismus / long sighted requiring spectacles
• Anxiety

Reported by many

• Poor sleep pattern
• Snoring, enlarged adenoids, tendency to breath through the mouth
• Poor fine and gross motor skills / clumsy / accident-prone
• Chronic constipation - can be fatal if unmanaged, see this information leaflet
• Abnormal electrical activity in the brain / seizures
• Hyporeflexia
• ADHD
• Exhibiting autistic traits / diagnosis of autism / autistic spectrum disorder
• Diagnosis of Pathological Demand Avoidance (PDA), see www.pdasociety.org.uk and www.autism.org.uk
• Diagnosis of Oppositional Defiant Disorder (OOD), see the difference between PDA and ODD
• Diagnosis of Sensory Processing Disorder
• Self-injurious behaviour / picking at scabs

Reported by some

• Memory loss / regression
• Poor thermoregulation
• Vitamin D deficiency
• Tongue tie
• Craniosynostosis

Kinderneurologie.eu

The Dutch website Kinderneurologie.eu has a section on KDM5C which is based on a review of scientific literature. An English translation can be downloaded from here.