Sichi Liu

This study was designed to assess the effectiveness of neonatal congenital adrenal hyperplasia (CAH) screening in Guangzhou, China. A total of 818,417 newborns were screened for CAH by measuring 17-hydroxyprogesterone (17-OHP) concentrations. Cut-off values were stratified based on gestational age (GA) and the timing of sample collection. Neonates with initial positive results (17-OHP ≥ cut-off value) were recalled for a second dried blood spot sample to reassess 17-OHP levels. Confirmatory testing involved biochemical analyses, Sanger sequencing, and multiplex ligation-dependent probe amplification of the CYP21A2 gene. From 2018 to 2024, a total of 40 patients with classical 21-hydroxylase deficiency were identified, including 28 cases (70%) of the salt-wasting form and 12 cases (30%) of the simple virilizing form. The overall incidence of CAH was 1 in 20,653 (95% confidence interval: 1:34,928, 1:14,661). No statistically significant differences in prevalence were observed between sexes or between preterm and full-term infants (p > 0.05). 17-OHP concentrations are influenced by GA and the timing of sample collection. The screening efficiency for CAH could be improved by adopting a multitiered cut-off value system adjusted for GA and collection time.

The aim of this study was to improve screening efficiency by establishing reasonable interpretation criteria for the use of flow injection analysis tandem mass spectrometry (FIA-MS/MS) in newborn screening (NBS) for X-linked adrenoleukodystrophy (X-ALD). FIA-MS/MS was employed to analyze very-long-chain acylcarnitines (ACs) and lysophosphatidylcholines (LPCs) and their ratios in dried blood spot (DBS) obtained from five X-ALD patients in the neonatal period (0–7 days old) and 7123 healthy neonate controls. By comparing these results and analyzing receiver operating characteristic (ROC) curves, we identified sensitive indicators for X-ALD screening in newborns. To evaluate the performance of different FIA-MS/MS screening indicators, we simultaneously analyzed 7712 neonatal DBS samples obtained for X-ALD screening using FIA-MS/MS and the established liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantitative detection of C26:0-lysophosphatidylcholine (C26:0-LPC). Furthermore, 84,268 newborn X-ALD screening results were retrospectively analyzed to further evaluate the screening performance of FIA-MS/MS. After the three-step optimization evaluation, the optimized first-tier sensitive screening indicators of FIA-MS/MS were C24:0-AC, C26:0LPC, and C24:0/C22:0-AC. Among the 7712 newborns screened, one case was confirmed to be double-positive. Within separate statistical analyses, based on LC-MS/MS screening alone (positive cutoff > 0.17 µmol/L), only seven cases (0.09%) were initially positive, with a positive predictive value (PPV) of 42.8%, and two additional ABCD1 VUS hemizygous males were detected. Through the retrospective analysis of 84,268 newborns, eight ABCD1 variants (six hemizygous males and two heterozygous females) were ultimately identified. Our study showed that the optimization of first-tier screening performance is particularly important if second-tier screening is not performed. Using LC-MS/MS for second-tier screening for X-ALD can significantly reduce the number of false positives, but the method still misses some false negatives. If it is used as a first-tier assessment, more VUS variant neonates can be detected.

Background: GM1 gangliosidosis (GM1) is an autosomal recessive disorder characterized by the deficiency of beta-galactosidase (β-gal), a ubiquitous lysosomal enzyme that catalyzes the hydrolysis of GM1 ganglioside. Objective: The study aims to explore the application of the AAV9-coGLB1 for effective treatment in a GM1 gangliosidosis mutant mouse model. Methods: We designed a novel adeno-associated virus 9 (AAV9) vector expressing β-gal (AAV9- coGLB1) to treat GM1 gangliosidosis. The vector, injected via the caudal vein at 4 weeks of age, drove the widespread and sustained expression of β-gal for up to 32 weeks in the Glb1^G455R/G455R mutant mice (GM1 mice). Results: The increased levels of β-gal reduced the pathological damage occurring in GM1 mice. Histological analyses showed that myelin deficits and neuron-specific pathology were reduced in the cerebral cortex region of AAV9-coGLB1-treated mice. Immunohistochemical staining showed that the accumulation of GM1 ganglioside was also reduced after gene therapy. The reduction of the storage in these regions was accompanied by a decrease in activated microglia. In addition, AAV9 treatment reversed the blockade of autophagic flux in GM1 mice. Conclusion: These results show that AAV9-coGLB1 reduces the pathological signs of GM1 gangliosidosis in a mouse model.