Pontocerebellar hypoplasia type 1B (PCH1B) is a condition that causes the lower back part of the brain (the cerebellum and pons) to not fully develop, leading to neurocognitive disabilities and the gradual loss of spinal motor neurons. Other possible signs include developmental delays, muscle stiffness or weakness, breathing problems, difficulty with eye movement, limited intellectual abilities, and often, early death in infancy. However, more recent research has found that in some cases, children with milder symptoms can grow and live well beyond their first year.
Main Clinical Features
● Hypotonia: Low muscle tone; the body may feel “floppy” or weak. (Generally, appears at birth, but later onset is also possible.)
● Spasticity:Muscle stiffness or tightness that can lead to jerky or rigid movements.
● Dystonia:Involuntary muscle contractions that cause twisting, tremors, or awkward body positions.
● Developmental Delay: A child may be slow to reach milestones like sitting, crawling, walking, or talking.
● Intellectual Disability:Challenges with thinking, learning, and problem-solving.
Less Common
● Respiratory/Swallowing Insufficiency:Difficulty breathing or swallowing, which may lead to choking, lung infections, or needing help to breathe.
● Oculomotor Dysfunction: Problems with eye movement—such as trouble tracking objects, jerky eye movements, or focusing.
● Seizures:Sudden abnormal brain activity that can cause shaking, staring spells, confusion, or brief loss of awareness.
EXOSC3