CTNNB1 syndrome is a genetic neurodevelopmental condition. The CTNNB1 gene makes a protein
called beta-catenin, which helps cells communicate and plays an important role in brain
development. When CTNNB1 does not work properly, brain development and motor pathways can be
affected.
Many cases are caused by a new (de novo) change, meaning it is not inherited from parents. A
change in just one copy of the gene can be enough to cause the condition.
This is a severe neurodevelopmental condition. Published studies describe moderate to severe
intellectual disability, absent or very limited speech, and significant movement challenges
such as motor delay and spasticity. Vision problems are also common. These features often have a
major impact on walking, communication, and day-to-day independence.
Families often notice:
- Developmental delay or intellectual disability
- Limited or absent speech
- Movement challenges, including motor delay and spasticity
- Vision problems
- Small head size (microcephaly) in some children
In the medical literature, CTNNB1 syndrome is also described as a neurodevelopmental disorder
with spastic diplegia and visual defects (NEDSDV). Large genetic studies of cerebral palsy show
CTNNB1 among genes with damaging de novo mutations associated with CP risk, which helps explain
why some children first receive a CP diagnosis before genetic testing provides the underlying
genetic cause.
Sources: Verhoeven et al., 2020
(PubMed), Kuechler et al., 2015
(PubMed)