Clinical characteristics and outcomes of acute liver failure in neonates: a retrospective cohort in China.

Neonatal acute liver failure (NALF), as a rare disease with high mortality, has limited relevant literature reports in China. We attempted to analyze a NALF cohort to improve the prognosis of this disease. We included all patients diagnosed with NALF at our institution between 2016 and 2021 and retrospectively reviewed their electronic records. NALF was defined as an INR ≥ 2.0 due to liver disease 28 days after birth. Comparisons were made according to etiology and outcome. The Kaplan-Meier method was used to estimate survival. Fifty-eight patients were included in this study. Etiologies included hypoxic/ischemic injury (29.3%), infection (27.6%), gestational alloimmune liver disease with neonatal hemochromatosis (GALD-NH) (10.3%), inherited metabolic diseases (5.2%), hemophagocytic lymphohistiocytosis (1.7%), other etiologies (12.1%), and unidentified causes (13.8%). Enteroviruses constituted 87.5% of the viral infections, whereas herpes simplex virus accounted for no infections. The median INR was significantly lower in the infection group than in the GALD-NH group (P < 0.05 for multiple comparisons). At the last follow-up, none of the patients had undergone liver transplantation, and the overall mortality rate was 50%. Liver function completely recovered in 31% of the patients, all of whom survived. The overall median survival time was 48 days; 26 days for hypoxic/ischemic injury and 43 days for GALD-NH. The incidence of cholestasis was significantly greater among surviving patients (P = 0.018).   Conclusion: Hypoxic/ischemic injury and infection are the predominant etiologies of NALF in China. The overall prognosis of NALF is poor, but its short-term prognosis is determined by the etiology. What is Known: • Neonatal acute liver failure (NALF) is a rare disorder with limited cohort studies, especially in China. • Gestational alloimmune liver disease, viral infections (especially herpes simplex virus), metabolic diseases and ischemic insults are common etiologies of NALF, which are significantly different from other populations. • There are no reliable biochemical markers to predict the outcome of NALF. What is New: • In this first report on a Chinese NALF cohort, we demonstrate that hypoxic/ischemic injury and infection (excluding herpes simplex virus) are the predominant etiologies of NALF. • The overall prognosis of NALF is poor, and its etiology determines the short-term outcome.

Primary carnitine deficiency: Estimation of prevalence in Chinese population and insights into newborn screening.

Primary carnitine deficiency (PCD) caused by pathogenic variants in the solute carrier family 22 member 5 (SLC22A5) gene is a rare autosomal recessive disease that results in defective fatty acid oxidation. PCD can be detected through tandem mass spectrometry (MS/MS), but transplacental transport of free carnitine from mothers may cause false negatives or positives during newborn screening (NBS). This study aimed to analyze the genetic characteristics of SLC22A5 and estimate the prevalence of PCD in the Chinese population, providing useful information for NBS and genetic counseling. We manually curated SLC22A5 pathogenic or likely pathogenic (P/LP) variants according to the American College of Medical Genetics and Genomics (ACMG) guidelines and identified 128 P/LP variants. Based on the China Neonatal Genomes Project (CNGP), the estimated PCD prevalence was 1:17,456, which was higher than that in other populations. The genotype-phenotype association analysis showed that patients carrying homozygous c.760C>T and c.844C>T were more likely to present cardiomyopathy, whereas those carrying homozygous c.1400C>G were more likely to be asymptomatic (all p-values < 0.05). We found that there was no significant difference in initial C0 concentrations between patients and carriers, but there was a significant difference in the second-tier screening of C0 concentration between them (p-value < 0.05). We established a cost-effective variant panel containing 10 high-frequency sites and developed a screening algorithm incorporating gene panels with MS/MS, which could rescue one more patient who was undetected from MS/MS. In conclusion, the prevalence of PCD in the Chinese population is relatively high. The combination of conventional NBS with genetic sequencing is suggested for early diagnosis of PCD.