1. Identification of a novel nonsense SLC16A2 gene mutation in an infant with severe neurologic phenotype: A case report.
- Author
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Peng W, Shi S, Yang L, and Liu D
- Subjects
- Humans, Male, Infant, Phenotype, Mental Retardation, X-Linked genetics, Mental Retardation, X-Linked diagnosis, Thyroxine therapeutic use, Muscle Hypertonia genetics, Muscle Hypertonia diagnosis, Exome Sequencing methods, Monocarboxylic Acid Transporters genetics, Codon, Nonsense, Muscle Hypotonia genetics, Muscle Hypotonia diagnosis, Symporters genetics, Muscular Atrophy genetics, Muscular Atrophy diagnosis
- Abstract
Rationale: Allan-Herndon-Dudley syndrome (AHDS) results from a pathogenic variant in the hemizygous subunit of the SLC16A2 gene, which encodes monocarboxylate transporter 8 and follows an X-linked recessive pattern. AHDS manifests as neuropsychomotor developmental delay, intellectual disability, movement disorders, and thyroid hormone abnormalities. It is frequently misdiagnosed as cerebral palsy or hypothyroidism., Patient Concerns: A 9-month-old male infant exhibited poor head control, hypodynamia, motor retardation, hypertonic limbs, and thyroid abnormalities. Despite levothyroxine supplementation and rehabilitation therapy, no improvements were observed. Whole-exome sequencing identified a novel nonsense mutation in SLC16A2 (c.124G > T, p.E42X), which unequivocally established the diagnosis., Diagnoses: AHDS was confirmed., Interventions: Levothyroxine treatment commenced early in infancy, followed by 3 months of rehabilitation therapy, starting at 5 months of age. The combined administration of levothyroxine and methimazole was initiated at 1 year and 10 months of age, respectively., Outcomes: While improvements were noted in thyroid hormone levels, neurological developmental delays persisted., Lessons: AHDS should be considered in patients presenting with atypical neurological features and thyroid hormone abnormalities such as elevated triiodothyronine and decreased thyroxine levels. The early utilization of exome sequencing aids in prompt diagnosis. The identified SLC16A2 nonsense mutation correlates with severe neurological phenotypes and adds to the spectrum of genetic variations associated with AHDS., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)
- Published
- 2024
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