MAP3K1 Variant Causes Hyperactivation of Wnt4/β-Catenin/FOXL2 Signaling Contributing to 46,XY Disorders/Differences of Sex Development

A Risk of Gonadoblastoma in Familial Swyer Syndrome-A Case Report and Literature Review

A complete gonadal dysgenesis (CGD) with 46,XY karyotype is known as the Swyer syndrome and belongs to the group of 46,XY differences of sex development (DSD). The main problem in patients with Swyer syndrome is the delayed puberty and primary amenorrhea. Moreover, intrabdominal dysgenetic gonads in the patient with genetic material of a Y chromosome may conduce to the development of gonadal tumors, such as gonadoblastoma or germinoma. The management of such patients is based on preventive excision of dysgenetic gonads and long-term hormonal replacement therapy. Sporadic cases are considered more common than familial cases. This paper presents two siblings with Swyer syndrome in whom gonadoblastoma was found. A thorough review of familial CGD with 46,XY DSD in the literature from the last 15 years suggests that the risk of gonadal tumors could be increased in familial compared to sporadic cases (66.6% vs. 15-45%, respectively).

Novel pathogenic NPR2 variants in short stature patients and the therapeutic response to rhGH

OBJECTIVE

Heterozygous loss-of-function variants in the NPR2 gene cause short stature with nonspecific skeletal abnormalities and account for about 2 ~ 6% of idiopathic short stature. This study aimed to analyze and identify pathogenic variants in the NPR2 gene and explore the therapeutic response to recombinant growth hormone (rhGH).

METHODS

NPR2 was sequenced in three Chinese Han patients with short stature via exome sequencing. In vitro functional experiments, homology modeling and molecular docking analysis of variants were performed to examine putative protein changes and the pathogenicity of the variants.

RESULT

Three patients received rhGH therapy for two years, and two NPR2 heterozygous variants were identified in three unrelated cases: c.1579 C > T,p.Leu527Phe in patient 1 and c.2842dupC,p.His948Profs*5 in patient 2. Subsequently, a small gene model was constructed, and transcriptional analysis of the synonymous variant (c.2643G > A) was performed in patient 3, which revealed the deletion of exon 17 and the premature formation of a stop codon (p.His840Gln*). Functional studies showed that both NPR2 variants, His948Profs*5 and His840Gln*, failed to produce cGMP in the homozygous state. Furthermore, the Leu527Phe variant of NPR2 was almost unresponsive to the stimulatory effect of ATP on CNP-dependent guanylyl cyclase activity. This loss of response to ATP has not been previously reported. The average age of patients at the start of treatment was 6.5 ± 1.8 years old, and their height increased by 1.59 ± 0.1 standard deviation score after 2 years of treatment.

CONCLUSION

In this report, two novel variants in NPR2 gene were described. Our findings broaden the genotypic spectrum of NPR2 variants in individuals with short stature and provid insights into the efficacy of rhGH in these patients.

Genome-wide identification, evolution and expression analysis of bone morphogenetic protein (BMP) gene family in chinese soft-shell turtle (Pelodiscus sinensis)

Introduction: Bone morphogenetic proteins (BMPs) play a crucial role in bone formation and differentiation. Recent RNA-Seq results suggest that BMPs may be involved in the sex differentiation of P. sinensis, yet more relevant studies about BMPs in P. sinensis are lacking. Methods: Herein, we identified BMP gene family members, analyzed the phylogeny, collinear relationship, scaffold localization, gene structures, protein structures, transcription factors and dimorphic expression by using bioinformatic methods based on genomic and transcriptomic data of P. sinensis. Meanwhile, qRT-PCR was used to verify the RNA-Seq results and initially explore the function of the BMPs in the sex differentiation of P. sinensis. Results: A total of 11 BMP genes were identified, 10 of which were localized to their respective genomic scaffolds. Phylogenetic analysis revealed that BMP genes were divided into eight subfamilies and shared similar motifs ("WII", "FPL", "TNHA", "CCVP", and "CGC") and domain (TGF-β superfamily). The results of the sexually dimorphic expression profile and qRT-PCR showed that Bmp2, Bmp3, Bmp15l, Bmp5, Bmp6 and Bmp8a were significantly upregulated in ovaries, while Bmp2lb, Bmp7, Bmp2bl and Bmp10 were remarkable upregulated in testes, suggesting that these genes may play a role in sex differentiation of P. sinensis. Discussion: Collectively, our comprehensive results enrich the basic date for studying the evolution and functions of BMP genes in P. sinensis.

Role of p38 MAPK Signalling in Testis Development and Male Fertility

The testis is an important male reproductive organ, which ensures reproductive function via the secretion of testosterone and the generation of spermatozoa. Testis development begins in the embryonic period, continues after birth, and generally reaches functional maturation at puberty. The stress-activated kinase, p38 mitogen-activated protein kinase (MAPK), regulates multiple cell processes including proliferation, differentiation, apoptosis, and cellular stress responses. p38 MAPK signalling plays a crucial role in testis development by regulating spermatogenesis, the fate determination of pre-Sertoli, and primordial germ cells during embryogenesis, the proliferation of testicular cells in the postnatal period, and the functions of mature Sertoli and Leydig cells. In addition, p38 MAPK signalling is involved in decreased male fertility when exposed to various harmful stimuli. This review will describe in detail the biological functions of p38 MAPK signalling in testis development and male reproduction, together with its pathological role in male infertility.