PRIM1 deficiency causes a distinctive primordial dwarfism syndrome.

DNA replication is fundamental for cell proliferation in all organisms. Nonetheless, components of the replisome have been implicated in human disease, and here we report PRIM1 encoding the catalytic subunit of DNA primase as a novel disease gene. Using a variant classification agnostic approach, biallelic mutations in PRIM1 were identified in five individuals. PRIM1 protein levels were markedly reduced in patient cells, accompanied by replication fork asymmetry, increased interorigin distances, replication stress, and prolonged S-phase duration. Consequently, cell proliferation was markedly impaired, explaining the patients' extreme growth failure. Notably, phenotypic features distinct from those previously reported with DNA polymerase genes were evident, highlighting differing developmental requirements for this core replisome component that warrant future investigation.

Comparison of flexible nasogastric tube and semi-rigid catheter during less invasive surfactant administration.

BACKGROUND: Various flexible and semi-rigid catheter techniques have been reported for surfactant delivery during less invasive surfactant administration (LISA) in preterm infants. Data on the effect of catheter selection on procedural success rates and adverse events are limited. Our objective was to compare the rates of success and adverse events of LISA performed with nasogastric tube and semi-rigid catheter. METHODS: This was a post-hoc analysis of data from a quality improvement project. LISA was performed according to the standardized local protocol. Baseline characteristics, data on performance of LISA, degree of difficulty in laryngoscopy and vital parameters after the initiation of LISA were collected and outcomes were compared between groups. RESULTS: Fifty-six infants were included (21 with nasogastric tube, and 35 with semi-rigid catheter). Procedure success rate (defined as a single LISA attempt resulting in intratracheal administration of the planned dose of surfactant), incidence of adverse events, heart rate and oxygen saturation values and outcomes did not differ significantly between the two groups. When using a nasogastric tube for LISA, a significantly higher fraction of inspired oxygen was needed in the 3rd (0.62 vs. 0.48, P=0.024), 4th (0.61 vs. 0.37, P<0.001) and 5th minute (0.48 vs. 0.37, P=0.001) to maintain normal oxygen saturations. CONCLUSIONS: Use of the semi-rigid catheter was associated with better oxygenation during and shortly after the procedure. Our results may help neonatal units to develop local guidelines.