title: Case report: 5 year follow-up of adult late-onset mitochondrial encephalomyopathy with lactic acid and stroke-like episodes (MELAS).
abstract: Mitochondrial encephalomyopathy with lactic acid and stroke-like episodes (MELAS) is a multisystem mitochondrial disorder that typically presents in childhood. We describe the follow-up of a patient who was diagnosed with late-onset MELAS at the age of 49. Her clinical course includes sensorineural hearing loss, seizures, and multiple episodes of stroke-like metabolic crises. Molecular genetic testing on whole blood revealed 31% heteroplasmy of a m.3243A > G variant in the mtDNA, the causative variant in approximately 80% of MELAS cases. The original diagnostic criteria for MELAS required the onset of stroke-like episodes prior to 40 years of age but this case and others demonstrate that onset may be delayed in certain individuals. Therefore, MELAS should be included in the differential diagnosis of stroke-like episodes in patients of any age.
authors.affiliation: Mayo Medical School, Mayo Clinic, Rochester, MN, United States.
authors.forename: Kiri
authors.initials: K
authors.lastname: Sunde
authors.affiliation: Department of Clinical Genomics, Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, United States.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Blackburn
authors.affiliation: Department of Clinical Genomics, Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, United States.
authors.forename: Anvir
authors.initials: A
authors.lastname: Cheema
authors.affiliation: Department of Clinical Genomics, Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, United States.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Gass
authors.affiliation: Department of Clinical Genomics, Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, United States.
authors.forename: Jessica
authors.initials: J
authors.lastname: Jackson
authors.affiliation: Department of Clinical Genomics, Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, United States.
authors.forename: Sarah
authors.initials: S
authors.lastname: Macklin
authors.affiliation: Department of Clinical Genomics, Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, United States.
authors.forename: Paldeep S
authors.initials: PS
authors.lastname: Atwal
keywords: MELAS, Mitochondrial encephalomyopathy with lactic acid and stroke-like episodes; mtDNA, Mitochondrial DNA