Spectrum of PHEX Mutations and FGF23 Profiles in a Taiwanese Cohort With X-Linked Hypophosphatemia Including 102 Patients.

BACKGROUND/AIM: X-linked hypophosphatemia (XLH), the most common form of hereditary rickets, results from loss-of-function mutations in the phosphate-regulating PHEX gene. Elevated fibroblast growth factor 23 (FGF23) contributes to hypophosphatemia in XLH. This study aimed to characterize PHEX variants and serum FGF23 profiles in Taiwanese patients with XLH. PATIENTS AND METHODS: We retrospectively reviewed the records of 102 patients clinically suspected of having hypophosphatemic rickets from 2006 to 2022. Serum intact Fibroblast growth factor-23 (iFGF23) levels were measured on clinic visit days. PHEX mutations were identified using Sanger sequencing, and negative cases were analyzed using whole-exome sequencing. RESULTS: The majority (92.1%) of patients exhibited elevated FGF23 compared with normal individuals. Among 102 patients, 44 distinct PHEX mutations were identified. Several mutations recurred in multiple unrelated Taiwanese families. We discovered a high frequency of novel PHEX mutations and identified variants associated with extreme FGF23 elevation and tumorigenesis. CONCLUSION: Our findings revealed the PHEX genotypic variants and FGF23 levels in Taiwanese patients with XLH. These results are crucial given the recent approval of burosumab, a monoclonal FGF23 antibody, for XLH therapy. This study provides key insights into the clinical management of XLH in Taiwan.

Elucidating the Cancer Phenotype in Turner Syndrome: A 20-Year Observational Cohort Study.

BACKGROUND/AIM: Turner syndrome confers increased cancer susceptibility; however, large-scale epidemiological evidence is lacking. This study aimed to analyze the incidence and prevalence of various malignancies in patients with Turner syndrome over 20 years of age to inform screening strategies. PATIENTS AND METHODS: We performed a retrospective cohort analysis of 11,502 patients with Turner syndrome from 2000 to 2020 utilizing the TriNetX research network database. The outcomes encompassed the incidence and prevalence of 20 cancers. Stratified analyses were used to evaluate variations in age, sex, and race. RESULTS: Key findings demonstrated markedly elevated risks of breast (1.7%), colon (1.0%), renal (0.4%), gonadoblastoma (0.4%), and other cancers. Significant demographic variations were observed in the incidence of cancers, such as gonadoblastoma, renal, and colon cancer. CONCLUSION: This large real-world study offers novel insights into the spectrum of cancer risk across adulthood in Turner syndrome. Our findings elucidate Turner syndrome's complex cancer phenotype to inform clinical decision-making, prognostication, and tailored screening strategies to ultimately advance patient care.

Molecular Cloning and Characterization of a New Family VI Esterase from an Activated Sludge Metagenome.

A new esterase gene, est6, was discovered in an activated sludge metagenomic library. The 729-bp gene encodes a 242-amino acid protein (designated Est6) with a molecular mass of 26.1 kDa. Est6 shared only a moderate identity to a putative hydrolase with the highest BLASTP analysis score. Most of the closely related proteins are uncharacterized and are predicted from genome sequencing data of microorganisms or metagenomic DNA sequences. The phylogenetic analysis of Est6 showed that the protein was assigned to family VI esterases/lipases. The catalytic triad of Est6 was predicted to be Ser135, Asp188, and His219, with Ser135 in a typically conserved pentapeptide (GFSQG) of family VI members, which was further confirmed by site-directed mutagenesis. The est6 gene was overexpressed successfully in its soluble form in Escherichia coli and then purified to its tag-free form and homogeneity by affinity chromatography. The purified Est6 in pH 8.0 buffer was active as a monomer. The optimal conditions for Est6 activity were at a temperature of 45 °C and pH of 8.0 when using p-nitrophenyl acetate as a substrate. The enzyme was stable over wide temperature and pH ranges, and it exhibited activity in the presence of organic solvents, metal cations, or detergents. Furthermore, the enzyme showed significant regioselectivity in the spectrophotometric analysis. In conclusion, Est6 might have the potential for applications in biotechnological processes.