It is characterized by craniosynostosis, and myopathy in association with congenital generalized hypertrichosis.[4] Patients with the disease are considered intellectually disabled. Most die in childhood. Patients often suffer from respiratory difficulties such as pneumonia, and from seizures due to dysmyelination in the brain's white matter.[5] It has been hypothesized that the Moro reflex (startle reflex in infants) may be a tool in detecting the congenital clapsed thumb early in infancy.[6] The thumb normally extends as a result of this reflex.