1. Christianson syndrome across the lifespan: genetic mutations and longitudinal study in children, adolescents, and adults.
- Author
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Kavanaugh BC, Elacio J, Best CR, St Pierre DG, Pescosolido MF, Ouyang Q, Biedermann J, Bradley RS, Liu JS, Jones RN, and Morrow EM
- Subjects
- Humans, Adolescent, Adult, Longitudinal Studies, Male, Child, Female, Young Adult, Child, Preschool, Ataxia genetics, Ataxia pathology, Ataxia physiopathology, Genetic Diseases, X-Linked genetics, Genetic Diseases, X-Linked pathology, Phenotype, Ocular Motility Disorders genetics, Ocular Motility Disorders physiopathology, Hypogonadism genetics, Hypogonadism pathology, Epilepsy, Mutation, Sodium-Hydrogen Exchangers genetics, Intellectual Disability genetics, Intellectual Disability pathology, Microcephaly genetics, Microcephaly pathology
- Abstract
Objectives: Mutations in the X-linked endosomal Na+/H+ exchanger 6 (NHE6) cause Christianson syndrome (CS). Here, in the largest study to date, we examine genetic diversity and clinical progression in CS into adulthood., Method: Data were collected as part of the International Christianson Syndrome and NHE6 ( SLC9A6 ) Gene Network Study. 44 individuals with 31 unique NHE6 mutations, age 2-32 years, were followed prospectively, herein reporting baseline, 1 year follow-up and retrospective natural history., Results: We present data on the CS phenotype with regard to physical growth and adaptive and motor regression across the lifespan including information on mortality. Longitudinal data on body weight and height were examined using a linear mixed model. The rate of growth across development was slow and resulted in prominently decreased age-normed height and weight by adulthood. Adaptive functioning was longitudinally examined; a majority of adult participants (18+ years) lost gross and fine motor skills over a 1 year follow-up. Previously defined core diagnostic criteria for CS (present in>85%)-namely non-verbal status, intellectual disability, epilepsy, postnatal microcephaly, ataxia, hyperkinesia-were universally present in age 6-16; however, an additional core feature of high pain tolerance was added (present in 91%). While neurologic examinations were consistent with cerebellar dysfunction, importantly, a majority of individuals (>50% older than 10) also had corticospinal tract abnormalities. Three participants died during the period of the study., Conclusions: In this large and longitudinal study of CS, we begin to define the trajectory of symptoms and the adult phenotype thereby identifying critical targets for treatment., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2024
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