Protein-losing enteropathy as a new phenotype in atypical hemolytic uremic syndrome caused by CD46 gene mutation.

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a life-threatening thrombotic microangiopathy. Genetic defects in the alternative complement (AP) pathway have been identified in 60-70% of individuals. Eculizumab is recommended as a first-line therapy. METHODS: We collected the clinical data of a pediatric patient with aHUS accompanied by protein-losing enteropathy (PLE). Genetic testing was performed. Related literature on aHUS combined with PLE was reviewed. RESULTS: A 15-year-old Chinese girl was diagnosed with aHUS at 3.7 years of age and experienced five episodes; her symptoms completely resolved with plasma treatment. Severe gastrointestinal symptoms and hypoalbuminemia presented after the first episode, and PLE was diagnosed. A novel homozygous CD46 variant was identified, and FACS revealed significantly decreased CD46 expression. She presented at a recent relapse with persistent GI symptoms and headache and progressed to chronic kidney failure; peritoneal dialysis was initiated. Eculizumab was given 8 months after the last recurrence. Surprisingly, PLE was cured. Afterward, dialysis was discontinued, and eGFR recovered to 44.8 ml/min/1.73 m2. A review of the literature indicated that PLE with thrombosis was caused by CD55 variants via hyperactivation of the AP system. We report an aHUS patient with PLE caused by CD46 variants. Symptoms of both PLE and aHUS were significantly alleviated in our patient and patients with CD55 variants treated with eculizumab, indicating that PLE was a new symptom of aHUS in our patient with a CD46 variant. CONCLUSIONS: Our case expands the phenotype of aHUS caused by a CD46 mutation and provides evidence of the efficacy of eculizumab after a long phase of chronic kidney failure.

Ginsenoside compound K induces ferroptosis via the FOXO pathway in liver cancer cells.

Liver cancer is a common malignant tumor worldwide, traditional Chinese medicine is one of the treatment measures for liver cancer because of its good anti-tumor effects and fewer toxic side effects. Ginsenoside CK (CK) is an active component of ginseng. This study explored the mechanism by which CK induced ferroptosis in liver cancer cells. We found that CK inhibited the proliferation of HepG2 and SK-Hep-1 cells, induced ferroptosis of cells. Ferrostatin-1, an ferroptosis inhibitor, was used to verify the role of CK in inducing ferroptosis of liver cancer cells. Network pharmacological analysis identified the FOXO pathway as a potential mechanism of CK, and western blot showed that CK inhibited p-FOXO1. In cells treated with the FOXO1 inhibitor AS1842856, further verify the involvement of the FOXO pathway in regulating CK-induced ferroptosis in HepG2 and SK-Hep-1 cells. A HepG2 cell-transplanted tumor model was established in nude mice, and CK inhibited the growth of transplanted tumors in nude mice, p-FOXO1 was decreased in tumor tissues, and SLC7A11 and GPX4 expressions were also down-regulated after CK treatment. These findings suggested that CK induces ferroptosis in liver cancer cells by inhibiting FOXO1 phosphorylation and activating the FOXO signaling pathway, thus playing an antitumor role.

Clinical, genetic profile and therapy evaluation of 11 Chinese pediatric patients with Fanconi-Bickel syndrome.

BACKGROUND: Fanconi-Bickel syndrome (FBS) is a rare autosomal recessive disorder characterized by impaired glucose and galactose utilization as well as proximal renal tubular dysfunction. METHODS: Clinical, biochemical, genetic, treatment, and follow-up data for 11 pediatric patients with FBS were retrospectively analysed. RESULTS: Hepatomegaly (10/11), short stature (10/11) and hypophosphataemic rickets (7/11) were the most common initial symptoms. At diagnosis, all patients had decreased fasting blood glucose (FBG), plasma bicarbonate (HCO3-) and serum phosphorus, as well as elevated liver transaminases, alkaline phosphatase (AKP) and proximal renal tubular dysfunction. Two infant patients were misdiagnosed with transient neonatal diabetes mellitus. After therapy with uncooked cornstarch and conventional rickets treatment, remission of hepatomegaly was observed in all patients, with significant improvements in pre-prandial blood glucose, liver transaminases, triglyceride, plasma HCO3- and AKP (p < 0.05). At the last follow-up, 5/7 patients with elevated AKP had nephrocalcinosis. The mean height standard deviation score (Ht SDS) of eight patients with regular treatment increased from - 4.1 to -3.5 (p = 0.02). Recombinant human growth hormone (rhGH) was administered to 4/9 patients, but their Ht SDS did not improve significantly (p = 0.13). Fourteen variants of the SLC2A2 gene were identified, with six being novel, among which one was recurrent: c.1217T > G (p.L406R) (allele frequency: 4/22, 18%). Patients with biallelic missense variants showed milder metabolic acidosis than those with null variants. Two of five patients from nonconsanguineous families with rare homozygous variations showed 5.3 Mb and 36.6 Mb of homozygosity surrounding the variants, respectively; a region of homozygosity (ROH) involving the entire chromosome 3 covering the SLC2A2 gene, suggesting uniparental disomy 3, was detected in one patient. CONCLUSIONS: Early diagnosis of FBS is difficult due to the heterogeneity of initial symptoms. Although short stature is a major issue of treatment for FBS, rhGH is not recommended in FBS patients who have normal GH stimulation tests. Patients with biallelic null variants may require alkali supplementation since urine bicarbonate loss is genetically related. ROH is a mechanism for rare homozygous variants of FBS in nonconsanguineous families.

Long-read sequencing solves complex structure of CYP21A2 in a large 21-hydroxylase deficiency cohort.

CONTEXT: Genetic testing for 21-hydroxylase deficiency (21-OHD) is always challenging. Current approaches, short-read sequencing and multiplex ligation-dependent probe amplification (MLPA), are insufficient for the detection of chimeric genes or complicated variants from multiple copies. Recently developed long-read sequencing (LRS) can solve this problem. OBJECTIVE: To investigate the clinical utility of LRS in precision diagnosis of 21-hydroxylase deficiency. METHODS: In the cohort of 832 patients with 21-OHD, the current approaches provided the precise molecular diagnosis for 81.7% (680/832) of cases. LRS was performed to solve the remaining 144 cases with complex chimeric variants and eight cases with variants from multiple copies. Clinical manifestations in patients with continuous deletions of CYP21A2 extending to TNXB (namely CAH-X) were further evaluated. RESULTS: Using LRS in combination with previous genetic test results, a total of 16.9% (281/1664) CYP21A1P/CYP21A2 or TNXA/TNXB chimeric alleles were identified in 832 patients, with CYP21A1P/CYP21A2 accounting for 10.4% and TNXA/TNXB for 6.5%. The top three common chimeras were CYP21 CH-1, TNX CH-1 and TNX CH-2, accounting for 77.2% (217/281) of all chimeric alleles. The eight patients with variants on multiple copies of CYP21A2 were accurately identified with LRS. The prevalence of CAH-X in our cohort was 12.1%, and a high frequency of connective tissue-related symptoms was observed in CAH-X patients. CONCLUSION: LRS can detect all types of CYP21A2 variants, including complex chimeras and pathogenic variants on multiple copies in patients with 21-OHD, which could be utilized as a first-tier routine test for the precision diagnosis and categorization of congenital adrenal hyperplasia.