Table 5.

SUCLA2-Related Mitochondrial DNA Depletion Syndrome, Encephalomyopathic Form with Methylmalonic Aciduria: Treatment of Manifestations

Manifestation/ConcernTreatmentConsiderations/Other
Developmental delay /
Intellectual disability 		See Developmental Delay / Intellectual Disability Management Issues.
Dystonia Standardized treatment for dystonia by experienced neurologist
Hypertonia/Spasticity Orthopedics / physical medicine & rehab / PT & OT incl stretching to help avoid contractures & fallsConsider need for positioning & mobility devices, disability parking placard.
Epilepsy Standardized treatment w/ASM by experienced neurologist
  • Many ASMs may be effective; none has been demonstrated effective specifically for this disorder.
  • Education of parents/caregivers 1
Sensorineural hearing impairment Hearing aids &/or cochlear implantation may be helpful per otolaryngologist & audiologist.Community hearing services through early intervention or school district
Feeding difficulties / GERD / Growth deficiency / Failure to thrive
  • Nutritional support by dietitian
  • Feeding therapy
  • Gastrostomy tube placement may be required for persistent feeding issues.
  • Low threshold for clinical feeding eval &/or radiographic swallowing study when showing clinical signs or symptoms of dysphagia
  • Intervention for GERD/vomiting as indicated
Vision/Ophthalmologic OphthalmologistStrabismus, ptosis, ophthalmoplegia
Ophthalmic subspecialistBlepharoplasty for significant ptosis
Low vision services
  • Children: through early intervention programs &/or school district
  • Adults: low vision clinic &/or community vision services / OT / mobility services
Respiratory
  • Chest physiotherapy
  • Aggressive antibiotic treatment of chest infections
Artificial ventilation (incl assisted nasal ventilation or intubation & use of tracheostomy & ventilator) for respiratory insufficiency (See Ethics consultation in this table.)
Skeletal
  • PT to help maintain muscle function & prevent joint contractures
  • Bracing or surgery for kyphoscoliosis per orthopedist
Family/Community
  • Ensure appropriate social work involvement to connect families w/local resources, respite, & support.
  • Coordinate care to manage multiple subspecialty appointments, equipment, medications, & supplies.
  • Ongoing assessment of need for palliative care involvement &/or home nursing
  • Consider involvement in adaptive sports or Special Olympics.
Ethics consultation Clinical ethics services
  • Assess health care decisions in the context of the best interest of the child & values & preferences of the family.
  • For difficult life-prolonging decisions or for clarification of treatment options, consider further consultation w/independent clinical teams. 2

ASM = antiseizure medication; GERD = gastroesophageal reflux disease; OT = occupational therapy; PT = physical therapy

1.

Education of parents/caregivers regarding common seizure presentations is appropriate. For information on non-medical interventions and coping strategies for children diagnosed with epilepsy, see Epilepsy Foundation Toolbox.

2.

From: SUCLA2-Related Mitochondrial DNA Depletion Syndrome, Encephalomyopathic Form with Methylmalonic Aciduria

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