X-linked neurodegenerative syndrome, Hamel type is a very rare genetic condition that has been observed in about ten male members across two generations of one family. The condition is characterized by several serious features, including intellectual deficits, blindness, convulsions (seizures), spasticity (muscle stiffness), and signs of mild hypomyelination (reduced myelin in the brain). These features lead to early death in affected individuals. The genetic defect causing this disorder is located in the pericentromeric region of the X chromosome (specifically, Xp11.3-q12). Because the condition follows an X-linked inheritance pattern, it primarily affects male family members. This summary is based on available trusted sources and is intended to provide a basic understanding of the condition.

People with this condition can experience intellectual deficits, blindness, convulsions, spasticity, and signs of mild hypomyelination. These symptoms manifest during early life and are severe in nature.

The cause of this disorder is a genetic mutation located in the pericentromeric region of the X chromosome (Xp11.3-q12). The mutation follows an X-linked pattern, which means it is typically seen in males who inherit the altered gene. This genetic defect disrupts normal brain development and function.