title: An unusual case of a spasticity-lacking phenotype with a novel SACS mutation.
abstract: The authors describe an unusual case of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) without leg spasticity, which is a core clinical feature of ARSACS. This is the second family with a spasticity-lacking phenotype in ARSACS. A peripheral nerve conduction study disclosed decreases in motor and sensory nerve conduction velocities with the disease progression. Although the leg spasticity is reported to become progressively worse during the disease and is prevalent in older patients, we first observed that the symptom had disappeared, probably due to the progressive peripheral nerve degeneration in the disease course. Thus, we should analyze the SACS gene even in cases of early-onset cerebellar ataxia without spasticity. The patient had a novel homozygous 2-base pair deletion mutation (c.5988-9 del CT) of the SACS gene, but the genotype was different from that in our first family of this phenotype. A further genotype-phenotype correlation study is required to clarify the molecular mechanism underlying 'sacsinopathies'.
authors.affiliation: Division of Neurology, Department of Internal Medicine, Jichi Medical University, Yakushiji 3311-1, Shimotsuke, Tochigi 329-0498, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Shimazaki
authors.forename: Kumi
authors.initials: K
authors.lastname: Sakoe
authors.forename: Kenji
authors.initials: K
authors.lastname: Niijima
authors.forename: Imaharu
authors.initials: I
authors.lastname: Nakano
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Takiyama
mesh_terms: D001259:Ataxia / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D004252:DNA Mutational Analysis; D018450:Disease Progression; D005260:Female; D020233:Gait Disorders, Neurologic / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D005808:Genes, Recessive / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006360:Heat-Shock Proteins / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007564:Japan; D008875:Middle Aged; D009128:Muscle Spasticity / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D009154:Mutation / Q000235:genetics*; D010525:Peripheral Nerves / Q000473:pathology / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D010641:Phenotype; D017384:Sequence Deletion; D013577:Syndrome; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D005819:Genetic Markers; D006360:Heat-Shock Proteins; C404403:SACS protein, human