SPAST mutations are the most common cause of hereditary spastic paraplegia (SPG4-HSP), which is characterized by progressive lower limb weakness, spasticity and hyperreflexia.
Mutations of human spastin, an AAA (ATPases associated with diverse cellular activity) family protein, cause an autosomal dominant form of hereditary spastic paraplegia, which is characterized by weakness, spasticity and loss of the vibratory sense in the lower limbs.
Hereditary spastic paraparesis (HSP) denotes a group of inherited neurological disorders with progressive lower limb spasticity as their clinical hallmark; a large proportion of autosomal dominant HSP belongs to HSP type 4, which has been linked to the SPG4 locus on chromosome 2.
Potent suppression of stretch reflex activity after systemic or spinal delivery of tizanidine in rats with spinal ischemia-induced chronic spastic paraplegia.
Xq28 duplications encompassing MECP2 have been described in male patients with a severe neurodevelopmental disorder associated with hypotonia and spasticity, severe learning disability, stereotyped movements, and recurrent pulmonary infections.
Chromosome Xq28 duplications encompassing methyl-CpG-binding protein 2 gene (MECP2) are observed most in males with a severe neurodevelopmental disorder associated with hypotonia, spasticity, severe learning disability, delayed psychomotor development, and recurrent pulmonary infections.
Specific mutations in MECP2 cause Rett syndrome (RTT) in females whereas other mutations in the same gene cause several other syndromes in males, including X-linked intellectual disability (with and without spasticity) (OMIM 300055) and X-linked intellectual disability due to increased dosage of MECP2 (OMIM 300260).
Male patients with large duplications of the methyl CpG-binding protein 2 (MECP2) gene have been identified with a characteristic phenotype consisting of infantile hypotonia replaced by spasticity, developmental delay, severe mental retardation and recurrent respiratory infections.
Duplication of MECP2 causes a recently described X-linked mental retardation syndrome, of which the typical features are infantile hypotonia, poor speech development, recurrent infections, epilepsy, and progressive spasticity.
Semi-dominant X-chromosome linked learning disability with progressive ataxia, spasticity and dystonia associated with the novel MECP2 variant p.V122A: akin to the new MECP2 duplication syndrome?
Xq28 duplications encompassing MECP2 have been described in male patients with a severe neurodevelopmental disorder associated with hypotonia and spasticity, severe learning disability and recurrent pneumonia.