Hajdu-Cheney Syndrome with Fatal Progressive Basilar Invagination: Illustrative Case.

Background: Hajdu-Cheney Syndrome is an autosomal dominantly inherited disease, with less than 50 patients reported to date. It is associated with gain-of-function variants of the NOTCH2 gene on chromosome 1p12. Methods: Here we present a case of NOTCH2 gene-associated Hajdu-Cheney syndrome with a progressive basilar impression and consecutive hydrocephalus. While the neuropsychologic development of the patient remained uneventful, allowing him to obtain his college exam, neurosurgical and orthopedic interventions became necessary to treat basal invagination and hydrocephalus at the age of 13 years. Results: Finally, the progressive compression of the medulla oblongata led to respiratory problems with the need for tracheotomy. The patient succumbed to his disease at the age of 18. Conclusions: To our knowledge, this is the first case in which a combination of hydrocephalus and basilar impression lead to a fatal outcome in spite of preemptive surgical interventions.