X-连锁先天性肾上腺发育不良（AHC）是一种罕见的先天疾病，主要表现为失盐的肾上腺皮质功能不全、低促性腺激素型性腺功能减退（HH）以及不育。本文报道1例临床主要表现为HH的迟发AHC病例，患者为青年男性，以第二性征发育不全为主要表现，性激素检测提示HH，促性腺激素释放激素兴奋试验无反应，促肾上腺皮质激素升高，皮质醇基本正常。进一步行全外显子测序检测提示患者NR0B1（DAX-1）基因第二外显子有1个新的错义突变：c.1352（exon2）C>T。构建突变的NB0R1基因转录因子表达质粒并与包含黄体生成素β亚基（LHβ）基因启动子的质粒共转染COS7细胞株，行双荧光素酶检测，最终证实该突变能造成NR0B1功能的部分缺失。.

DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia congenital critical region on X chromosome gene 1), a key sex determinant in various species, plays a vital role in gonad differentiation and development and controls spermatogenesis. However, the identity and function of DAX1 are still unclear in bivalves. In the present study, we identified a DAX1 (designed as Tc-DAX1) gene from the boring giant clam Tridacna crocea, a tropical marine bivalve. The full length of Tc-DAX1 was 1877 bp, encoding 462 amino acids, with a Molecular weight of 51.81 kDa and a theoretical Isoelectric point of 5.87 (pI). Multiple sequence alignments and phylogenetic analysis indicated a putative ligand binding domain (LBD) conserved regions clustered with molluscans DAX1 homologs. The tissue distributions in different reproductive stages revealed a dimorphic pattern, with the highest expression trend in the male reproductive stage, indicating its role in spermatogenesis. The DAX1 expression data from embryonic stages shows its highest expression profile (P < 0.05) in the zygote stage, followed by decreasing trends in the larvae stages (P > 0.05). The localization of DAX1 transcripts has also been confirmed by whole mount in situ hybridization, showing high positive signals in the fertilized egg, 2, and 4-cell stage, and gastrula. Moreover, RNAi knockdown of the Tc-DAX1 transcripts shows a significantly lower expression profile in the ds-DAX1 group compared to the ds-EGFP group. Subsequent histological analysis of gonads revealed that spermatogenesis was affected in a ds-DAX1 group compared to the ds-EGFP group. All these results indicate that Tc-DAX1 is involved in the spermatogenesis and early embryonic development of T. crocea, providing valuable information for the breeding and aquaculture of giant clams.

Adrenal hypoplasia congenita, attributed to NR0B1 pathogenic variants, accounts for more than 50% of the incidence of primary adrenal insufficiency in children. Although more than 250 different deleterious variations have been described, no genotype-phenotype correlation has been defined to date. We report a case of an adopted boy who reported the onset of an adrenal crisis at 2 weeks of age, requiring replacement therapy with mineralocorticoids and glucocorticoids for 4 months. For 3 years, he did well without treatment. At almost 4 years of age, the disorder was restarted. A long follow-up showed the evolution of hypogonadotropic hypogonadism. Molecular studies on NR0B1 revealed a novel and deleterious deletion-insertion-inversion-deletion complex rearrangement sorted in the 5\'-3\' direction, which is described as follows: (1) deletion of the intergenic region (between TASL and NR0B1 genes) and 5\' region, (2) insertion of a sequence containing 37 bp at the junction of the intergenic region of the TASL gene and a part of exon 1 of the NR0B1 gene, (3) inversion of a part of exon 1, (4) deletion of the final portion of exon 1 and exon 2 and beginning of the 3\'UTR region, (5) maintenance of part of the intergenic sequence (between genes MAGEB1 and NR0B1, telomeric sense), (6) large posterior deletion, in the same sense. The path to molecular diagnosis was challenging and involved several molecular biology techniques. Evaluating the breakpoints in our patient, we assumed that it was a nonrecurrent rearrangement that had not yet been described. It may involve a repair mechanism known as nonhomologous end-joining (NHEJ), which joins two ends of DNA in an imprecise manner, generating an \"information scar,\" represented herein by the 37 bp insertion. In addition, the local Xp21 chromosome architecture with sequences capable of modifying the DNA structure could impact the formation of complex rearrangements.

46,XY gonadal dysgenesis (GD) is a disorder of sex development due to incomplete gonadal differentiation into testes, resulting in female to ambiguous external genitalia. Duplications at the Xp21.2 locus involving the NR0B1 (DAX1) gene have previously been associated with 46,XY GD. More recently, a complex structural variant not directly involving NR0B1 has been reported in 46,XY GD illustrating that the mechanism of how copy number variants (CNVs) at Xp21.2 may cause 46,XY gonadal dysgenesis is not yet fully understood. Here, we report on three families in which a duplication involving the NR0B1 gene was detected in the context of prenatal screening. This is the first report of duplications involving NR0B1 in three phenotypically normal males in two families. Fertility problems were present in one adult male carrier. The data reported here from an unbiased screening population broaden the phenotype associated with CNVs involving NR0B1, and this may aid clinicians in counseling and decision making in the prenatal context.

NR0B1 is frequently activated in hepatocellular carcinoma (HCC). However, the role of NR0B1 is controversial in HCC. In this study, we observed that NR0B1 was an independent poor prognostic factor, negatively correlated with the overall survival of HCC and the relapse-free survival of patients treated with sorafenib. Meanwhile, NR0B1 promoted the proliferation, migration, and invasion of HCC cells, inhibited sorafenib-induced apoptosis, and elevated the IC50 of sorafenib in HCC cells. NR0B1 was further displayed to increase sorafenib-induced autophagic vesicles and activate Beclin1/LC3-II-dependent autophagy pathway. Finally, NR0B1 was revealed to transcriptionally suppress GSK3β that restrains AMPK/mTOR-driven autophagy and increases BAX-mediated apoptosis. Collectively, our study uncovered that the ectopic expression of NR0B1 augmented sorafenib-resistance in HCC cells by activating autophagy and inhibiting apoptosis. Our findings supported that NR0B1 was a detrimental factor for HCC prognosis.

X-linked adrenal hypoplasia congenita is a rare cause of primary adrenal insufficiency. Mutations in the NR0B1 gene cause a loss of function in the DAX1 receptor, which activates genes involved in the development and function of the hypothalamic-pituitary-gonadal axis. Objective: To describe a case of adrenal hypoplasia congenita secondary to a mutation in the NR0B1 gene and identified the differential diagnoses of the pediatric patient with adrenal insufficiency and hypogonadotropic hypogonadism. Clinical Case: A 4-year-old male patient with no relevant history and from a rural area was admitted to the emergency room due to a 15-days of emesis, asthenia, adynamia, myalgia, and ataxic gait. On the physical examination, hypotension, hyponatremia, and hyperkalemia, as well as mucosal hyperpigmentation and bilateral cryptorchidism were observed, therefore, adrenal crisis was diagnosed, starting fluid resuscitation with saline solution, hydrocortisone, and fludrocortisone, which stabilized the patient. Adrenal hyperplasia congenita, innate metabolic error, and infectious or autoimmune etiology were ruled out as etiology. A clinical exome test was performed which iden tified the variant c.1275A > T; p.Arg425Ser (Transcript ENST00000378970.5) in the NR0B1 gene consistent with X-linked adrenal hypoplasia congenita. Management of the patient continued with glucocorticoids and mineralocorticoids with favorable clinical course at 7 years of follow-up. Con clusion: A novel pathogenic variant associated with X-linked adrenal hypoplasia is described. Variants in the NR0B1 gene should be a differential diagnosis in a male patient with the association of primary adrenal insufficiency and hypogonadism.

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.

Dax1 (Nr0b1; Dosage-sensitive sex reversal-adrenal hypoplasia congenital on the X-chromosome gene-1) is an important component of the transcription factor network that governs pluripotency in mouse embryonic stem cells (ESCs). Functional evaluation of alternative splice variants of pluripotent transcription factors has shed additional insight on the maintenance of ESC pluripotency and self-renewal. Dax1 splice variants have not been identified and characterized in mouse ESCs. We identified 18 new transcripts of Dax1 with putative protein-coding properties and compared their protein structures with known Dax1 protein (Dax1-472). The expression pattern analysis showed that the novel isoforms were cotranscribed with Dax1-472 in mouse ESCs, but they had transcriptional heterogeneity among single cells and the subcellular localization of the encoded proteins differed. Cell function experiments indicated that Dax1-404 repressed Gata6 transcription and functionally replaced Dax1-472, while Dax1-38 and Dax1-225 partially antagonized Dax1-472 transcriptional repression. This study provided a comprehensive characterization of the Dax1 splice variants in mouse ESCs and suggested complex effects of Dax1 variants in a self-renewal regulatory network.

Coupling the release of pituitary hormones to the developmental stage of the oocyte is essential for female fertility. It requires estrogen to restrain kisspeptin (KISS1)-neuron pulsatility in the arcuate hypothalamic nucleus, while also exerting a surge-like effect on KISS1-neuron activity in the AVPV hypothalamic nucleus. However, a mechanistic basis for this region-specific effect has remained elusive. Our genomic analysis in female mice demonstrate that some processes, such as restraint of KISS1-neuron activity in the arcuate nucleus, may be explained by region-specific estrogen receptor alpha (ERα) DNA binding at gene regulatory regions. Furthermore, we find that the Kiss1-locus is uniquely regulated in these hypothalamic nuclei, and that the nuclear receptor co-repressor NR0B1 (DAX1) restrains its transcription specifically in the arcuate nucleus. These studies provide mechanistic insight into how ERα may control the KISS1-neuron, and Kiss1 gene expression, to couple gonadotropin release to the developmental stage of the oocyte.

X-linked adrenal hypoplasia congenita (AHC) is a rare disorder, often manifesting as primary adrenal insufficiency (PAI) and hypogonadotropic hypogonadism (HH), and caused by variants of NR0B1, most of which are frame-shifting variants, and few splice-site variants.
Here, a novel splice-site variant of NR0B1 (NM_000475.4), c.1169-2A>T (patient 1), and a stop-loss variant of NR0B1 c.1411T>C (patient 2) are described in this study. We perform minigene assays for the splice-site variant (c.1169-2A>T) and determine that the variant causes exon 2 skipping. Moreover, the defect of NR0B1 protein may bring about the severe phenotype of the patient. Through 8 years of follow-up, we compare the CT images from 8 years ago with the latest image, and observe the CT image change of adrenal in patient 2 (from the increased thickness of adrenal to adrenal atrophy).
X-linked adrenal hypoplasia congenita is produced by variants of NR0B1. We report a case that presents a novel splice-site variant, which has been verified that it could lead to the exon 2 skipping in the RNA splicing progress. Moreover, we report the adrenal CT image change of patient 2, which has never been referred to before, and expand the spectrum of X-linked AHC characteristics.