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©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
Early-onset refractory diarrhea due to immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome associated with a novel mutation in the FOXP3 gene: A case report
Na Su, Cheng Chen, Xia Zhou, Guo-Da Ma, Ri-Ling Chen, Chuan Tian
Na Su, Department of Pediatrics, Shunde Women and Children's Hospital, Guangdong Medical University, Foshan 528300, Guangdong Province, China
Na Su, Department of Pediatrics, Guangdong Medical University, Zhanjiang 524000, Guangdong Province, China
Cheng Chen, Ri-Ling Chen, Department of Pediatric Internal Medicine, Shunde Women and Children's Hospital, Guangdong Medical University, Foshan 528300, Guangdong Province, China
Xia Zhou, Department of Neurology, Guangdong Medical University, Zhanjiang 524000, Guangdong Province, China
Guo-Da Ma, Maternal and Child Research Institute, Shunde Women and Children's Hospital, Guangdong Medical University, Foshan 528300, Guangdong Province, China
Chuan Tian, Department of Pediatric Hematology, Affiliated Hospital of Guangdong Medical University, Zhanjiang 524000, Guangdong Province, China
Author contributions: Su N, Ma GD, and Zhou X reviewed the literature, contributed to drafting of the manuscript, and prepared the figures and table; Chen C, Chen RL, and Tian C discussed the diagnosis and treatment; all authors issued final approval for the version to be submitted.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Ri-Ling Chen, MD, Professor, Department of Pediatric Internal Medicine, Shunde Women and Children's Hospital, Guangdong Medical University, No. 3, Baojian Road, Foshan 528300, Guangdong Province, China. chenrl319@163.com
Received: January 16, 2020
Peer-review started: January 16, 2020
First decision: March 5, 2020
Revised: April 1, 2020
Accepted: April 21, 2020
Article in press: April 21, 2020
Published online: May 26, 2020
BACKGROUND
Immune dysregulation, polyendocrinopthy, enteropathy, X-linked (IPEX) syndrome is a rare X-linked recessive disease caused by mutations in the forkhead box protein 3 (FOXP3) gene, which is a master transcriptional regulator for the development and function of CD4+CD25+ regulatory T (Treg) cells. The dysfunction of these cells leads to multiple system autoimmune diseases. We present a case of IPEX due to a mutation not reported in the literature before.
CASE SUMMARY
We report a male patient with IPEX syndrome who presented with refractory diarrhea and malabsorption leading to failure to thrive, as well as with hypothyroidism and nephrotic syndrome. Laboratory investigation showed increased total IgE and Treg cells, decreased free triiodothyronine (FT3) and free thyroxine (FT4), and proteinuria. Multiple dietary and supportive treatments were introduced but did not improve the diarrhea during his hospital stay. Ultimately, whole exome sequencing revealed that the patient was hemizygous for the exon 5, c.542G>A (p.Ser181Asn) mutation of the FOXP3 gene, which has not been previously reported. The patient remains on prednisone and euthyrox while awaiting hematopoietic stem cell transplantation at the time of the compilation of this case report.
CONCLUSION
We report a novel FOXP3 gene mutation involved in IPEX. A high level of suspicion should be maintained in an early-onset refractory diarrhea patient.
Core tip: Immune dysregulation, polyendocrinopthy, enteropathy, X-linked syndrome is a rare X-linked recessive disease caused by mutations in the FOXP3 gene. Patients most commonly present symptoms with refractory diarrhea, type 1 diabetes mellitus, eczema, and rarely, symptoms of nephrotic syndrome, hypothyroidism, and thrombocytopenia. Herein, we present a patient with refractory diarrhea, failure to thrive, hypothyroidism, and nephrotic syndrome who was subsequently found to have a novel mutation in the FOXP3 gene [c.542G>A (p.Ser181Asn)]. Patients with immune dysregulation, polyendocrinopthy, enteropathy, X-linked generally require supportive treatments and replacement therapy, such as steroids, immunosuppressors, or hematopoietic stem cell transplantation.
