Single-cell sequencing reveals the relationship between phenotypes and genotypes of Klinefelter syndrome

One of the most common congenital disorders of male infertility is Klinefelter syndrome. Because of its extreme heterogeneity in clinical and genetic presentation, the relationship between transcriptome and the clinical phenotype and the associated co-morbidities seen in KS has not been fully clarified yet. We reported here a 47 XXY karyotype Chinese male (KS) with infertility and analyzed the differences in gene expression patterns of peripheral blood mononuclear cells (PBMCs) from a Chinese male and a female control with normal karyotype by single-cell sequencing. We analyzed a total of 24,439 cells and divided them into 5 immune cell types (including B cell, T cell, macrophage cell, dendritic cell, and natural killer cell) according to the marker genes. Using unsupervised dimensionality reduction and clustering algorithms, we identified molecularly distinct subpopulations of cells between KS and both controls. Gene ontology enrichment analyses yielded terms associated with well-known comorbidities seen in KS as well as an affected immune system, type I diabetes mellitus. Based on our data, we point towards several candidate genes, which may be implicated in the phenotype of KS. Overall, our analysis showed a comprehensive map of the cell types of the PBMCs of KS patient at the single-cell level, which will contribute to preventing comorbidity and improving the life quality of KS patients. Overall design: sequenced PBMCs from a Chinese male with Klinefelter syndrome by using single-cell sequencing technology