ObjectiveTo systematically review the clinical and genetic features of permanent neonatal diabetes mellitus (PNDM) case reports. MethodsThe PubMed, Embase, Scopus, SinoMed, Web of Science, CINAHL, Medrxiv, VIP, CNKI and WanFang Data databases were electronically searched to collect PNDM case reports from inception to June 2023. Two reviewers independently screened literature, extracted data and assessed the reporting quality of the included studies. Descriptive analysis was performed. ResultsA total of 105 case reports were finally included. Typical clinical manifestations of PNDM were early onset of persistent hyperglycemia, developmental delay and low birth weight. The results of genetic testing showed that mutations in the KCNJ11, INS, EIF2AK3, GCK, ABCC8, PTF1A, GATA6, IER3IP1, SLC19A2, NEUROG3, PDX1, and 6q24 genes were closely associated with the development of PNDM. In addition, there may be different clinical manifestations and prognosis of PNDM in different genotypes. ConclusionThis study reveales the clinical characteristics and genetic pattern of PNDM, and provides a direction for further research on the mechanism of PNDM.