Genetic Investigation and Transcriptome Profiling in a Nuclear Family With Peutz–Jeghers Syndrome

Peutz–Jeghers syndrome (PJS) is a rare autosomal dominant disorder hallmarked by mucocutaneous melanocytic macules and gastrointestinal hamartomatous polyposis associated with germline/somatic pathogenic variants in the tumor suppressor STK11. PJS is clinically heterogeneous; however, the relationship between clinical phenotype and genotype remains elusive. Here, we report a family with PJS that harbors a heterozygous STK11 whole gene deletion combined with a heterozygous variant in TP53AIP1 that segregates with mucocutaneous pigmentation in the family. RNA-seq analysis followed by qRT-PCR confirmed that the expression of STK11, TP53, and TP53AIP1 and a large fraction of p53 signaling pathway components are significantly reduced, while Wnt signaling pathway effectors are upregulated in cells from an affected individual. Our findings shed light on transcriptome-level pathway dysregulation in PJS with germline deletion of STK11. Further evaluation of mutational burden across relevant signaling pathways can likely inform disease prognosis.