Renpenning syndrome caused by the c.459_462delAGAG mutation in PQBP1: a case report and literature review

Background Renpenning syndrome (OMIM: 309500) is a rare X-linked intellectual disability caused by variations in the polyglutamine-binding protein 1 (PQBP1) gene, characterized by moderate to severe intellectual disability, microcephaly, short stature, lean body, small testes, and abnormal facial features. Methods Comprehensive clinical evaluation and whole exome sequencing were performed to identify the genetic basis of the clinical presentation in a 4-year-7-month-old male proband from a Chinese family. Detected variants underwent validation and familial segregation analysis by Sanger sequencing. Additionally, a literature review was conducted to analyze PQBP1-related genotype-phenotype correlations. Results The proband exhibited typical manifestations of Renpenning syndrome, including severe global developmental delay, microcephaly, short stature, and characteristic facial features. Additionally, he presented with rare anal atresia and co-occurring autism spectrum disorder (ASD). Whole exome sequencing identified a hemizygous PQBP1 frameshift variant, NM_001032382.2:c.459_462delAGAG (p.Arg153fs) (VCV000010980.79), in the proband. Sanger sequencing confirmed this variant was maternally inherited. Conclusion This report describes the first Chinese case of Renpenning syndrome caused by the PQBP1 c.459_462delAGAG variant, presenting with the core phenotype plus anal atresia and ASD. This case expands recognition of the clinical spectrum associated with PQBP1 variants.