A woman in her 50s was referred to genetic consultation owing to mitochondrial myopathy or cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) suspicion based on brain magnetic resonance imaging (Figure). She reported distal weakness for 10 years, cataracts 2 years prior, and ptosis 1 year prior. There was no history of migraine, stroke, or memory loss. No clinical or electrophysiological myotonia were found. Her father and aunt had early-onset bilateral cataracts and late-onset type 2 diabetes. Her father has neither muscular weakness nor myotonia or heart disease. Molecular analysis of DMPK revealed more than 50 CTG repeats in 1 allele, confirming myotonic dystrophy type 1 diagnosis in the index patient.
Konzen D, Moura de Souza CF, Saute JAM. A Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy Mimics on Brain Magnetic Resonance Imaging in Myotonic Dystrophy Type I. JAMA Neurol. Published online May 01, 2017. doi:10.1001/jamaneurol.2017.0399