PQBP1 and microcephaly: <h4>Background</h4>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.<h4>Methods</h4>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.