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©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
Clinical and genetic features of Kenny-Caffey syndrome type 2 with multiple electrolyte disturbances: A case report
Ning Yuan, Lin Lu, Xiao-Ping Xing, Ou Wang, Yue Jiang, Ji Wu, Ming-Hai He, Xiao-Juan Wang, Le-Wei Cao
Ning Yuan, Ming-Hai He, Xiao-Juan Wang, Le-Wei Cao, Department of Endocrinology, Nanchong Central Hospital, The Second Clinical College, North Sichuan Medical College, Nanchong 637000, Sichuan Province, China
Lin Lu, Xiao-Ping Xing, Ou Wang, Yue Jiang, Department of Endocrinology, Key Laboratory of National health commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing 100730, China
Ji Wu, Department of Urology, Nanchong Central Hospital, The Second Clinical College, North Sichuan Medical College, Nanchong 637000, Sichuan Province, China
Author contributions: Yuan N and Lu L designed the study; Yuan N wrote the manuscript; Xing XP, Wang O, Jiang Y, Wu J, He MH, Wang XJ and Cao LW collected, analyzed and interpreted the data; Lu L critically reviewed, edited and approved the manuscript; All authors read and approved the final manuscript.
Supported by National Natural Science Foundation of China, No. 82070817.
Informed consent statement: Written informed consent has been obtained from all patients.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
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:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Lin Lu, MD, Professor, Department of Endocrinology, Key Laboratory of National health commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, No. 1 Shuaifuyuan, Wangfujing, Dongcheng District, Beijing 100730, China. lulin88@sina.com
Received: December 2, 2022
Peer-review started: December 2, 2022
First decision: January 17, 2023
Revised: January 30, 2023
Accepted: March 15, 2023
Article in press: March 15, 2023
Published online: April 6, 2023
Processing time: 118 Days and 2.3 Hours
BACKGROUND
Hypoparathyroidism, which can be sporadic or a component of an inherited syndrome, is the most common cause of hypocalcemia. If hypocalcemia is accompanied by other electrolyte disturbances, such as hypokalemia and hypomagnesemia, then the cause, such as renal tubular disease, should be carefully identified.
CASE SUMMARY
An 18-year-old female visited our clinic because of short stature and facial deformities, including typical phenotypes, such as low ear position, depression of the nasal bridge, small hands and feet, and loss of dentition. The lab results suggested normal parathyroid hormone but hypocalcemia. In addition, multiple electrolyte disturbances were found, including hypokalemia, hypocalcemia and hypomagnesemia. The physical signs showed a short fourth metatarsal bone of both feet. The X-ray images showed cortical thickening of long bones and narrowing of the medulla of the lumen. Cranial computed tomography indicated calcification in the bilateral basal ganglia. Finally, the genetic investigation showed a de novo heterogenous mutation of “FAM111A” (c. G1706A:p.R569H). Through a review of previously reported cases, the mutation was found to be the most common mutation site in Kenny-Caffey syndrome type 2 (KCS2) cases reported thus far (16/23, 69.6%). The mutation was slightly more prevalent in females than in males (11/16, 68.8%). Except for hypocalcemia, other clinical manifestations are heterogeneous.
CONCLUSION
As a rare autosomal dominant genetic disease of hypoparathyroidism, the clinical manifestations of KCS2 are atypical and diverse. This girl presented with short stature, facial deformities and skeletal deformities. The laboratory results revealed hypocalcemia as the main electrolyte disturbance. Even though her family members showed normal phenotypes, gene detection was performed to find the mutation of the FAM111A gene and confirmed the diagnosis of KCS2.
Core Tip: The FAM111A mutation was more likely to be a de novo mutation. Since the patient was an adult at the time of consultation, long-term follow-up treatment and observation of electrolyte status is necessary. Moreover, the fertility of the patient and the genetics of her offspring should be determined.
