**A Case of X-Linked Adrenal Hypoplasia Congenital (AHC) Due to Large Deletion ofNR0B1(DAX1) and Contiguous Gene**

Shin, Chungwoo
Kim, Sung Eun
Moon, Cheong Jun
Yoo, Il Han
Yim, Jisook
Cho, Won-Kyong
Kim, Myungshin
Lee, Jung Hyun

¹Department of Pediatrics, College of Medicine, St. Vincent’s Hospital, The Catholic University of Korea, ²Department of Pediatrics, College of Medicine, Incheon St. Mary’s Hospital, The Catholic University of Korea, ³Department of Laboratory Medicine, Korea University Anam Hospital, ⁴Catholic Genetic Laboratory Center, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, and ⁵Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea

Address correspondence to Won Kyoung Cho, MD, PhD; Department of Pediatrics, College of Medicine, St. Vincent's Hospital, 93, Jungbudaero (Ji-dong), Paldal-gu, Suwon, Gyeonggi-do, Seoul, 442-723 Korea; phone: +82 32 249 8312; e mail: [email protected]

Annals of Clinical & Laboratory Science 53(4):p 667-670, July-August 2023.

Abstract

X-linked adrenal hypoplasia congenita (AHC) is caused predominantly by mutations in the NR0B1 (DAX1) gene. Among these, X-linked AHC due to a large deletion of NR0B1 is extremely rare. In Korea, the first case was reported in 2005, and there have been no further documented cases since then. Herein, we report a unique case of X-linked AHC caused by an entire gene deletion that includes the NR0B1 gene and seven other genes. A seven-day-old boy presented to a pediatric endocrine clinic with prolonged postnatal jaundice, skin hyperpigmentation, hyponatremia, and hyperkalemia, suggestive of an adrenal crisis. In genetic analysis, next-generation sequencing panel for congenital adrenal hyperplasia (CAH) showed no variants. However, chromosomal microarray results revealed large deletion of Xp21.2 (29,655,007_30,765,126) including eight protein-coding genes (NR0B1, IL1RAPL1, GK, MAGEB1-4, TASL). In cases of atypical adrenal insufficiency and genetically undiagnosed CAH, NR0B1-related AHC should be suspected, as Xp21 deletion is very rare and not detected in NGS, making microarray the best option for genetic diagnosis.