Table 5.

POLG-Related Disorders: Recommended Evaluations Following Initial Diagnosis

SystemEvaluationComment
Neurologic Neurologic eval
  • To incl brain MRI 1
  • Consider EEG & video EEG if seizures are a concern.
Ataxia Orthopedics / physical medicine & rehab / PT & OT evalTo incl assessment of:
  • Gross motor & fine motor skills
  • Mobility, ADL, & need for adaptive devices
  • Need for PT (to improve gross motor skills) &/or OT (to improve fine motor skills)
Development Developmental assessment
  • To incl motor, adaptive, cognitive, & speech-language eval
  • Eval for early intervention / special education, need for speech therapy
Neurobehavioral/
Psychiatric 		Neuropsychiatric evalFor persons age >12 mos: screening for concerns incl sleep disturbances, ADHD, anxiety, &/or findings suggestive of ASD. Formal neuropsychological eval can be considered for those w/any concerns identified on screening.
Depression screenAssess for mood disturbances.
Musculoskeletal Orthopedics / physical medicine & rehab / PT & OT evalTo incl assessment of:
  • Gross motor & fine motor skills
  • Contractures, clubfoot, & kyphoscoliosis
  • Mobility, ADL, & need for adaptive devices
  • Need for PT (to improve gross motor skills) &/or OT (to improve fine motor skills)
  • Consideration of exercise program
Gastrointestinal/
Feeding 		Gastroenterology / nutrition / feeding team eval
  • To incl liver function tests incl ALT & AST; serum concentrations of ammonia, glutamine & tyrosine, bilirubin, albumin, & cholesterol; fasting blood glucose levels; & coagulation factors (prothrombin time or INR) 2
  • Consideration of liver ultrasound to evaluate for liver fibrosis
  • To incl eval of aspiration risk incl swallow study for bulbar symptoms & nutritional status
  • Consider eval for gastrostomy tube placement in persons w/dysphagia &/or aspiration risk.
Eyes Ophthalmologic evalTo assess for reduced vision, abnormal ocular movement, best corrected visual acuity, refractive errors, strabismus, & more complex findings (e.g., cataract, retinal dystrophy) that may require referral for subspecialty care &/or low vision services
Hearing Audiologic evalAssess for hearing loss.
ENT/Mouth ENT evalA sleep study is recommended to evaluate for central or obstructive apnea or hypopnea that results in either pCO2 elevation or O2 desaturation.
Cardiovascular Cardiac evalTo incl echocardiogram & electrocardiogram
Respiratory Pulmonary evalTo incl baseline pulmonary function testing
Endocrine Screen for pancreatic, thyroid, & adrenal function.Consider if clinically indicated & in critical illness. 3
Pregnancy High-risk obstetrical careTo incl discussion between managing physicians
Genetic counseling By genetics professionals 4To inform affected persons & their families re nature, MOI, & implications of POLG-related disorders to facilitate medical & personal decision making
Family support
& resources 		By clinicians, wider care team, & family support organizationsAssessment of family & social structure to determine need for:

ADHD = attention-deficit/hyperactivity disorder; ADL = activities of daily living; ALT = alanine transaminase; ASD = autism spectrum disorder; AST = aspartate aminotransferase; INR = international normalized ratio; MOI = mode of inheritance; OT = occupational therapy; pCO2: partial pressure of carbon dioxide; PT = physical therapy

1.

In some instances, the first neuroimaging study may be normal, but with certain phenotypes, such as Alpers-Huttenlocher syndrome, changes may be seen in a relatively short amount of time.

2.

AST elevation, and to a lesser extent ALT elevation, may be due to muscle disease. Therefore, simultaneously obtaining a serum CK level helps differentiate between liver & muscle involvement, which can both be seen in individuals with POLG-related disorders.

3.
4.

Medical geneticist, certified genetic counselor, certified advanced genetic nurse

From: POLG-Related Disorders

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