Incidence of Organic Acid Disorders in 13 Million Chinese Newborns: A Systematic Review and Meta-Analysis.

Organic acid disorders (OADs) are inherited metabolic defects in the enzymes and cofactors involved in metabolic pathways. This systematic review and meta-analysis investigated the incidence and regional differences in OADs between the northern and southern regions of China. Searches of the PubMed, Embase, Web of Science, and Chinese databases (CNKI, Veipu, and Wanfang) revealed 1784 studies indexed between January 2002 and December 2024. After quality assessment and data extraction, the meta-analysis was conducted on OAD screening data from 57 studies involving 13,314,056 newborns and 1501 OAD cases in China. The seven most prevalent OADs were methylmalonic acidemia (MMA), 3-methylcrotonyl-CoA carboxylase deficiency, glutaric acidemia type I, isobutyryl-CoA dehydrogenase deficiency, isovaleric acidemia, 2-methylbutyryl-CoA dehydrogenase deficiency (2-MBD), and propionic acidemia. The meta-analysis revealed an OAD prevalence of 112.38 (95% confidence interval 106.70-118.07) per 1,000,000 newborns. The incidence of OADs and MMA was significantly higher in northern China than in southern China, whereas the incidence of 2-MBD was significantly lower in northern China than in southern China (p < 0.0001). Additionally, the ratio of MMA combined with homocystinuria to MMA was higher in northern China than in southern China (p < 0.05). These results provide valuable epidemiological insights and guidance for newborn screening for OADs in China.