Delineating the spectrum of impairments, disabilities, and rehabilitation needs in methylmalonic acidemia (MMA)

Am J Med Genet A. 2015 Sep;167A(9):2075-84. doi: 10.1002/ajmg.a.37127. Epub 2015 May 10.

Abstract

Methylmalonic acidemia patients have complex rehabilitation needs that can be targeted to optimize societal independence and quality of life. Thirty-seven individuals with isolated MMA (28 mut, 5 cblA, 4 cblB), aged 2-33 years, were enrolled in a natural history study, and underwent age-appropriate clinical assessments to characterize impairments and disabilities. Neurological examination and brain imaging studies were used to document movement disorders and the presence of basal ganglia injury. A range of impairments and disabilities were identified by a team of physical medicine experts. Movement disorders, such as chorea and tremor, were common (n = 31, 83%), even among patients without evidence of basal ganglia injury. Joint hypermobility (n = 24, 69%) and pes planus (n = 22, 60%) were frequent and, in many cases, under-recognized. 23 (62%) patients required gastrostomy feedings. 18/31 patients >4 years old (58%) had difficulties with bathing and dressing. 16 of 23 school-aged patients received various forms of educational support. Five of the 10 adult patients were employed or in college; three lived independently. Unmet needs were identified in access to rehabilitation services, such as physical therapy (unavailable to 14/31), and orthotics (unavailable to 15/22). We conclude that patients with MMA are challenged by a number of functional limitations in essential activities of mobility, self-care, and learning, in great part caused by movement disorders and ligamentous laxity. Early assessment, referral, and implementation of age-appropriate rehabilitation services should significantly improve independence and quality of life.

Keywords: basal ganglia; disabilities; methylmalonic acidemia; outcome; rehabilitation.

MeSH terms

  • Adolescent
  • Adult
  • Amino Acid Metabolism, Inborn Errors / rehabilitation*
  • Child
  • Child, Preschool
  • Disabled Persons / rehabilitation*
  • Female
  • Health Services Needs and Demand / statistics & numerical data*
  • Humans
  • Male
  • Neuroimaging / methods
  • Neurologic Examination / methods
  • Quality of Life
  • Self Care / methods
  • Young Adult

Supplementary concepts

  • Methylmalonic acidemia