Possibly associated with SPG4
A new mutation in SPG4 is found to be associated with slowly progressive cognitive decline, but the development of narcolepsy* prior to the onset of SPG4 symptoms is the first report of such occurrence. There may be an association between narcolepsy and HSP or it may be coincidence.
*Narcolepsy is a chronic neurological disorder that affects the brain’s ability to control sleep-wake cycles. People with narcolepsy may feel rested after waking, but then experience excessive uncontrollable daytime sleepiness.
Abstract
Spastic paraplegia type 4 (SPG4) is the most common type of hereditary spastic paraplegia (HSP) caused by the mutations in the SPAST gene, which encodes a microtubule-severing protein named spastin. Spastin regulates the number and mobility of microtubules and is essential for axonal outgrowth and neuronal morphogenesis.
Herein, we report a patient with SPG4 harboring a novel donor splice site mutation in the SPAST gene (c.1616+1dupG). Although SPG4 usually manifests itself as a pure form of HSP, this patient exhibited a slow progressive cognitive decline and also developed narcolepsy type 2 (narcolepsy without cataplexy) prior to the onset of SPG4. Recently, cognitive decline has attracted attention as a main non-motor symptom of SPG4. However, this is the first reported case of a patient developing both SPG4 and narcolepsy, although it remains unclear whether the manifestation of the two diseases is a coincidence or an association. In this report, we describe the clinical symptoms and genetic background of the patient.
SOURCE: Case Rep Neurol. 2021 Feb 15;13(1):84-91. doi: 10.1159/000512404. eCollection Jan-Apr 2021. PMID: 33708099
Coexistence of Hereditary Spastic Paraplegia Type 4 and Narcolepsy: A Case Report
Takahiro Nagai 1 2 , Yoko Sunami 3 , Risa Kato 4 , Megumi Sugai 4 , Makoto Takahara 5 , Kentaro Ohta 1 , Hidehiko Fujinaka 6 7 , Kiyoe Goto 8 , Osamu Okanura 4 , Takashi Nakajima 1 , Tetsuo Ozawa 5
1 Department of Neurology, National Hospital Organization Niigata National Hospital, Kashiwazaki, Japan.
2. Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
3. Department of Neurology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
4. Department of Clinical Laboratory, National Hospital Organization Niigata National Hospital, Kashiwazaki, Japan.
5. Department of Internal Medicine, National Hospital Organization Niigata National Hospital, Kashiwazaki, Japan.
6. Department of Pediatrics, National Hospital Organization Niigata National Hospital, Kashiwazaki, Japan.
7. Department of Clinical Research, National Hospital Organization Niigata National Hospital, Kashiwazaki, Japan.
8. Department of Genetic Counseling, National Hospital Organization Niigata National Hospital, Kashiwazaki, Japan.