IMR Press / JIN / Volume 21 / Issue 1 / DOI: 10.31083/j.jin2101035
Open Access Case Report
R233H mutation in patients with tyrosine hydroxylase deficiency and corresponding phenotypes: a study of four cases and literature review
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1 Department of Pediatrics, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
2 Outpatient Department, Beijing Children’s Hospital, Capital Medical University, 100045 Beijing, China
*Correspondence: yaonvshihao1@163.com (Chun-Mei Yao)
J. Integr. Neurosci. 2022, 21(1), 35; https://doi.org/10.31083/j.jin2101035
Submitted: 15 April 2021 | Revised: 10 May 2021 | Accepted: 24 May 2021 | Published: 28 January 2022
Copyright: © 2022 The Author(s). Published by IMR Press.
This is an open access article under the CC BY 4.0 license.
Abstract

Owing to the small number of patients with tyrosine hydroxylase (TH) deficiency, no genotype-phenotype correlations have yet been identified. To investigate the genotype-phenotype correlation of R233H mutation in TH deficiency, we analyzed the clinical manifestations and treatment responses of four patients with the R233H homozygous mutation. Thirty-eight additional patients, available from the literature, known to be homozygous or heterozygous for the R233H mutation, were combined with the four cases from our hospital. Data for a total of 42 patients were retrieved. Our four patients showed clinical presentation consistent with Type A TH deficiency, and responded well to levodopa therapy, with an improvement in clinical symptoms within 1–2 weeks. In the 42 patients, 20 of 42 patients (48%) were homozygous and 22 (52%) were heterozygous for the R233H mutation. Of the 20 patients who were homozygous for the R233H mutation, a majority (80%) suffered from Type A TH deficiency. Of the 8 patients that were heterozygous for the R233H/the mutation located downstream of exon 11, 7 patients (86%) suffered from Type B TH deficiency. Of the 7 patients who were heterozygous for the R233H/nonsense mutation, 6 (86%) suffered from Type B TH deficiency. Genotype-phenotype correlation of R233H mutation was observed in TH deficiency. The homozygous R233H mutation frequently manifests as Type A TH deficiency, whereas R233H/nonsense mutation or any mutation located downstream of exon 11 manifests as Type B TH deficiency.

Keywords
Tyrosine Hydroxylase Deficiency
R233H
Mutation
Genotype-phenotype
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