Background Male EBP disorder with neurologic defects (MEND syndrome) is an extremely rare disorder with a prevalence of less than 1/1,000,000 individuals worldwide. It is inherited as an X-linked recessive disorder caused by impaired sterol biosynthesis due to nonmosaic hypomorphic EBP variants. MEND syndrome is characterized by variable clinical manifestations including intellectual disability, short stature, scoliosis, digit...