Myelination Delay and Allan-Herndon-Dudley Syndrome Caused by a Novel Mutation in the SLC16A2 Gene.
Allan-Herndon-Dudley syndrome is an X-linked disease caused by mutations in the solute carrier family 16 member 2 (SLC16A2) gene. As SLC16A2 encodes the monocarboxylate transporter 8 (MCT8), a thyroid hormone transporter, patients with Allan-Herndon-Dudley syndrome present a specific altered thyroid hormone profile. Allan-Herndon-Dudley syndrome has been associated with myelination delay on the brain magnetic resonance imaging (MRI) of affected subjects. We report a patient with Allan-Herndon-Dudley syndrome characterized by developmental delay, hypotonia, and delayed myelination caused by a novel SLC16A2 mutation (p.L291R). The thyroid hormones profile in our patient was atypical for Allan-Herndon-Dudley syndrome. The follow-up examinations showed that the progression of the myelination was not accompanied by a clinical improvement. Our paper suggests that SLC16A2 mutations should be investigated in patients with myelination delay even when the thyroid function is not conclusively altered.
Laboratory of Neurogenetics of Movement, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada Department of Neuroradiology, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada roberta.lapiana@mail.mcgill.ca.
Roberta
R
La Piana
Department of Neuroscience, Division of Neurology, CHU-Sainte-Justine, Montreal, Canada.
Michel
M
Vanasse
Laboratory of Neurogenetics of Movement, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada Departments of Neurology, Neurosurgery and Human Genetics, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
Bernard
B
Brais
Department of Neuroscience, Division of Neurology, CHU-Sainte-Justine, Montreal, Canada Departments of Pediatrics, Neurology and Neurosurgery, division of Pediatric Neurology, Montreal Children's Hospital, Montreal, Canada.
Genevieve
G
Bernard
D001921:Brain / Q000254:growth & development / Q000473:pathology; D002170:Canada; D018450:Disease Progression; D005500:Follow-Up Studies; D005602:France / Q000208:ethnology; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D038901:X-Linked Intellectual Disability / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D027501:Monocarboxylic Acid Transporters / Q000235:genetics*; D009123:Muscle Hypotonia / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D009133:Muscular Atrophy / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D009154:Mutation; D009186:Myelin Sheath / Q000473:pathology / Q000502:physiology*; D027981:Symporters; D044465:White People / Q000235:genetics
D027501:Monocarboxylic Acid Transporters; C090735:SLC16A2 protein, human; D027981:Symporters
Allan-Herndon-Dudley syndrome; SLC16A2; myelination delay; thyroid function