AIMS: The aim of this study is to elucidate the genetic landscape of microspherophakia (MSP) and describe the genotype-phenotype correlation of MSP. Additionally, the study seeks to enhance the understanding of the pathogenic mechanisms of MSP through the discovery of novel loci. METHODS: Patients diagnosed with MSP at the Eye and ENT Hospital of Fudan University, Shanghai, were included in the study and all underwent panel-based next-generation sequencing and bioinformatics analysis. Comprehensive ophthalmologic evaluations were conducted for each participant. RESULTS: Our analysis encompassed 118 eyes from 59 patients with MSP, revealing 13 gene variations linked to the condition. Notably, FBN1 mutations were identified in 31 patients (52.5%), highlighting its higher prevalence. Among the genetic variations discovered, 28 represented novel mutations. Statistical analysis unveiled significant associations between specific gene mutations and ocular biometric parameters: axial length (AL, p = 0.011), Z-score axial length (Z-AL, p <
0.002), white-to-white (WTW, p = 0.009), Z-score white-to-white (p = 0.012), mean keratometry (p <
0.002), astigmatism (AST, p = 0.021), anterior chamber depth (ACD, p = 0.003), lens thickness (LT, p = 0.012) and central endothelial cell count/mm2 (p = 0.005). Patients with FBN1 mutations had the longest AL, while those with CBS mutations showed significantly wilder WTW measurements. Patients with ADAMTS17 mutations presented with increased LT and decreased WTW, ADAMTSL4 mutations were linked to the greater Km and AST. Patients with LTBP mutations exhibited the largest WTW, and ASPH mutations was associated with the shortest AL but thick LT. Additionally, there was a relationship among gene mutations, diagnostic age and ocular biometric parameters. CONCLUSION: The study demonstrates that MSP is associated with a diverse range of genetic mutations, with FBN1 being the most common. Novel mutations were identified, and significant correlations were found between specific genetic variations and ocular biometric parameters. These results provide new insights into the genetic underpinnings of MSP and its clinical characteristics, advancing our understanding of the condition's pathogenic mechanisms.