SPG 77 Info
Hereditary spastic paraplegia 77(SPG77)
MedGen UID:
1800430
•Concept ID:
•
Disease or Syndrome
Synonym:Spastic paraplegia 77, autosomal recessiveSNOMED CT:Autosomal recessive spastic paraplegia type 77 (1187506008)Modes of inheritance:
Autosomal recessive inheritance (Orphanet)
Gene (location):FARS2 (6p25.1) Monarch Initiative:MONDO:0014882OMIM®:617046Orphanet:ORPHA466722
Definition
The spectrum of FARS2 deficiency ranges from the infantile-onset phenotype, characterized by epileptic encephalopathy with lactic acidosis and poor prognosis (70% of affected individuals), to the later-onset phenotype, characterized by spastic paraplegia, less severe neurologic manifestations, and longer survival (30% of affected individuals). To date FARS2 deficiency has been reported in 37 individuals from 25 families. Infantile-onset phenotype. Seizures are difficult to control and may progress quickly at an early age to intractable seizures with frequent status epilepticus; some children have hypsarrhythmia on EEG. All have developmental delay; most are nonverbal and unable to walk. Feeding difficulties are common. More than half of affected children die in early childhood. Later-onset phenotype. All affected individuals have spastic paraplegia manifested by weakness, spasticity, and exaggerated reflexes of the lower extremities associated with walking difficulties; some have developmental delay/intellectual disability; some have brief seizures that resolve over time. [from GeneReviews]
Additional description
From OMIM
Spastic paraplegia-77 (SPG77) is an autosomal recessive neurologic disorder characterized by early-childhood onset of spasticity affecting the lower limbs and resulting in gait difficulties. The disorder is progressive and may be associated with childhood seizures, developmental delay, and mitochondrial dysfunction (Yang et al., 2016; Vernon et al., 2015; Vantroys et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive spastic paraplegia, see SPG5A (270800). http://www.omim.org/entry/617046
