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Jeong IH, Yoo JH, Kim N. A pathogenic PHEX variant (c.1483-1G>C) in a Korean patient with X-linked hypophosphatemic rickets. Ann Pediatr Endocrinol Metab 2021; 26:130-133. [PMID: 34218635 PMCID: PMC8255857 DOI: 10.6065/apem.2040186.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/21/2020] [Indexed: 11/28/2022] Open
Abstract
X-linked hypophosphatemic rickets is an X-linked dominantly inherited disorder characterized by defects in renal phosphate transport leading to phosphate wasting and hypophosphatemia. In this report, we describe a case of X-linked hypophosphatemic rickets in a patient with a rare pathogenic PHEX variant. The 25-year-old female patient came to our clinic for genetic counseling regarding presumed genetic disease and pregnancy. When she was 9 years old, she had been diagnosed with vitamin D-resistant rickets based on laboratory results and symptoms. She had undergone orthopedic surgery due to bowing leg deformities. Since then, she was intermittently self-prescribing oral phosphate and calcium supplements. At 25 years old, she was diagnosed with X-linked hypophosphatemic rickets with a rare pathogenic PHEX variant (c.1483-1G>C) by next-generation sequencing. This is the second report of the c.1483-1G>C variant to date, and her pathogenicity was confirmed based on the most recent guideline. Traditionally, the disease had been diagnosed mostly based on clinical findings. However, with advancements in genetic testing, genetic confirmation has become an imperative part of diagnostic workup. Herein, we report a 25-year-old female Korean patient diagnosed with X-linked hypophosphatemic rickets harboring a rare pathogenic PHEX variant.
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Affiliation(s)
- In Hwa Jeong
- Department of Laboratory Medicine, Dong-A University Hospital, Busan, Korea
| | - Jae-Ho Yoo
- Department of Pediatrics, Dong-A University Hospital, Busan, Korea
| | - Namhee Kim
- Department of Laboratory Medicine, Dong-A University Hospital, Busan, Korea,Address for correspondence: Namhee Kim Department of Laboratory Medicine, Dong-A University Hospital, 26 Daesingongwon-ro, Seo-gu, Busan 49201, Korea
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Jo HY, Shin JH, Kim HY, Kim YM, Lee H, Bae MH, Park KH, Jang JH, Kwak MJ. Identification of a novel variant in the PHEX gene using targeted gene panel sequencing in a 24-month-old boy with hypophosphatemic rickets. Ann Pediatr Endocrinol Metab 2020; 25:63-67. [PMID: 32252220 PMCID: PMC7136512 DOI: 10.6065/apem.2020.25.1.63] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/31/2019] [Indexed: 12/15/2022] Open
Abstract
Familial hypophosphatemic rickets (FHR) is a disorder characterized by phosphate wasting and hypophosphatemia due to defects in renal phosphate transport regulation. There are 4 known inherited forms of FHR that differ in their molecular causes. Very few studies have been conducted that focused on the molecular analysis of FHR in Koreans. Eighteen mutations of the PHEX gene have been identified to this date in Korea. Herein, we report the clinical case of a 24-month-old boy presenting with bowed legs and short stature. The biochemical profile showed hypophosphatemia with decreased tubular reabsorption of phosphate. Several family members were identified with short stature and genu varum. Therefore, he was diagnosed with FHR. To identify the molecular causes of FHR, we performed targeted gene panel sequencing and found a novel hemizygous missense variant, c.1949T>C (p.Leu650Pro), in the PHEX gene. This variant was also detected in the boy's mother who exhibited genu varum and short stature.
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Affiliation(s)
- Ha Young Jo
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Jung Hyun Shin
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Hye Young Kim
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Young Mi Kim
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Heirim Lee
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Mi Hye Bae
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Kyung Hee Park
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | | | - Min Jung Kwak
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea,Address for correspondence: Min Jung Kwak, MD, PhD Department of Pediatrics, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan 49241, Korea Tel: +82-51-240-7298 Fax: +82-51-248-6205 E-mail:
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Yang M, Kim J, Yang A, Jang J, Jeon TY, Cho SY, Jin DK. A novel de novo mosaic mutation in PHEX in a Korean patient with hypophosphatemic rickets. Ann Pediatr Endocrinol Metab 2018; 23:229-234. [PMID: 30599486 PMCID: PMC6312911 DOI: 10.6065/apem.2018.23.4.229] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/17/2018] [Accepted: 06/17/2018] [Indexed: 11/24/2022] Open
Abstract
X-linked hypophosphatemic rickets is caused by loss-of-function mutations in PHEX, which encodes a phosphate-regulating endopeptidase homolog. We report a 26-year-old man with X-linked hypophosphatemic rickets who showed decreased serum phosphate accompanied by bilateral genu valgum and short stature. He had received medical treatment with vitamin D (alfacalcidol) and phosphate from the age of 3 to 20 years. He underwent surgery due to valgus deformity at the age of 14 and 15. Targeted gene panel sequencing for Mendelian genes identified a nonsense mutation in PHEX (c.589C>T; p.Gln197Ter) and a mosaic pattern where only 38% of sequence reads showed the variant allele. This mutation was not found in his mother, who had a normal phenotype. This is a case of a sporadic nonsense mutation in PHEX and up to date, this is the first case of a mosaic mutation in PHEX in Korea.
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Affiliation(s)
- Misun Yang
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jinsup Kim
- Department of Pediatrics, Hanyang University Guri Hopistal, Hanyang University College of Medicine, Guri, Korea
| | - Aram Yang
- Department of Pediatrics, Inha University School of Medicine, Incheon, Korea
| | | | - Tae Yeon Jeon
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sung Yoon Cho
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Dong-Kyu Jin
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Lee WY. Articles in 'endocrinology and metabolism' in 2014. Endocrinol Metab (Seoul) 2015; 30:47-52. [PMID: 25827457 PMCID: PMC4384668 DOI: 10.3803/enm.2015.30.1.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Won Young Lee
- Department of Endocrinology and Metabolism, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
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