What are the signs and symptoms?
Children with UBE3B-related disorder typically show signs from very early in life.
Nearly all children will have:
• A distinctive facial appearance: narrow eye openings, droopy eyelids, thin eyebrows, a small jaw, and ears that sit lower than usual, sometimes with small skin tags in front of the ear.
• A small and slow-growing head:often already smaller than average at birth, with growth slowing further over time.
• Low muscle tone: babies often feel “floppy” from early infancy.
• Developmental delay:most children reach milestones such as sitting, walking, and talking later than other children, often with little or no spoken language; many children are nonetheless sociable and communicate in other ways.
• A specific brain scan finding:a structure called the corpus callosum, which connects the two halves of the brain, is often smaller than usual or, less often, partly missing.
Some children will also have:
• Eye problems:a smaller-than-usual cornea, crossed or wandering eyes, or nearsightedness
• Hearing loss
• Heart differences:such as a small hole in the heart, or, less often, a thickened heart muscle
• Breathing difficulties: noisy or labored breathing in infancy due to a floppy airway
• Feeding difficulties: related to low muscle tone and swallowing coordination
• Seizures: usually well controlled with standard anti-seizure medication
• Genital or kidney differences
• Long, slender fingers, or foot position differences such as club foot
The severity and exact combination of symptoms can vary from child to child, even within the same family.
UBE3B