Clinical Characteristics

All individuals with a mutation in the SUCLA2 gene have these features (based on 29 patients; 20 males, 9 females):

  • Onset birth-6 months.
  • (Truncal) muscle hypotonia.
  • Delayed motor development.
  • Sensorineural hearing loss.
  • Dystonia / Hyperkinesia.

Recognizable dysmorphisms:

  • None.

Most individuals with a mutation in the SUCLA2 gene also have these features:

  • Absent speech (but able to communicate via specially adapted electronic device).
  • Feeding problems.
  • Failure to thrive.
  • Gastro-oesophageal reflux.
  • Progressive spasticity.
  • Progressive kyphosis/scoliosis.
  • Ophthalmoplegia/strabismus/ptosis.
  • Hyperhidrosis.
  • Hypersalivation.
  • Intestinal dysmotility with frequent vomiting / constipation.
  • Basal ganglia lesions on MRI.

Other less frequently reported clinical features are:

  • Epilepsy.
  • Ataxia.
  • Athetosis.
  • Weak or absent deep tendon reflexes.
  • Cerebral atrophy on MRI.
  • Cerebellar atrophy on MRI.

Biochemical features of the SUCLA2 defect include:

  • Elevated serum lactate.
  • Elevated urinary lactate.
  • Mildly elevated plasma methylmalonate.
  • Mildly elevated urinary methylmalonate.
  • Elevated plasma/blood C4-dicarboxylic carnitine.

A comprehensive spectrum of clinical characteristics observed in patients with SUCLA2-related syndrome is available on the Graph and Charts page.

Life span varies greatly, from few weeks to >25 years. Mean age in 16 Faroese individuals 8 years; 10 months.