Fatal Familial Insomnia in a Canadian family (P1.317)

Objective: NA

Background: Fatal familial insomnia (FFI) is an autosomal dominant prion disease caused by a point mutations in the prion protein (PRNP) gene.¹ The age of onset is between the 3^rd and 6^th decade with a average onset of 50. FFI presents with insomnia and dysautonomia, while cognitive and motor symptoms appear later in the course of the disease. Polysomnography (PSG) can show reduction in total sleep time, deep sleep and REM reduction, sleep fragmentation as well as REM intrusion^2,3. Periodic limb movement and central apnea have also been described⁴.

Design/Methods: NA

Results: We report the case of a 48-year-old man with clinically and genetically confirmed FFI. He presented with tachycardia, progressive ataxia and poor sleep. He developed hallucinations, dysarthria, dysphagia requiring G-tube place. His cognitive and motor function declined over the course of 12 months. Polysomnography showed status dissociatus, a condition in which there is asynchronous occurrence of different stages of sleep and wakefulness³ and central apnea. The patient developed multiple aspiration pneumonias and passed away in hospital. The diagnosis was confirmed with genetic testing which showed PRNP c.532G>A (p.Asp178Asn) and PRNP c.385A>G (pMet129Val). His father had a similar presentation and died at age 48 and was suspect to also be affected. The mutation was confirmed in 2 of his bothers.

Conclusions: To our knowledge, this is the first case of genetically confirmed FFI in a Canadian family of Western European descent, as it has been described in a Canadian family of Chinese descent⁵.

Study Supported by: NA

Disclosure: Dr. Bendahan has nothing to disclose. Dr. Taylor has nothing to disclose. Dr. Boissé Lomax has nothing to disclose.