Billuart-type X-linked syndromic intellectual developmental disorder

A syndromic X-linked intellectual disability characterized by moderately to severely impaired intellectual development, cerebellar hypoplasia, and seizures that has_material_basis_in mutation in the oligophrenin-1 gene on chromosome Xq12.

Signs and symptoms

• Thin upper lip vermilion
• Intellectual disability
• Global developmental delay
• Ventriculomegaly
• Cerebellar vermis hypoplasia
• Generalized hypotonia
• Macrocephaly
• Strabismus
• Small scrotum
• Seizure

Also known as: X-linked mental retardation with cerebellar hypoplasia and distinctive facial appearance