Prenatal ultrasound findings and NIPS may facilitate identification of 15q duplication syndromeNew prenatal screening may help identify 15q duplication syndrome earlier

Background15q duplication (Dup15q) syndrome is a rare neurodevelopmental disorder characterized by early-onset hypotonia, developmental delay, intellectual disability, symptoms related to autism spectrum disorder and epilepsy. In the absence of specific treatment, prenatal diagnosis is of important clinical significance. However, most reported cases are postnatal cases, whereas prenatal cases are limited and often lack detailed clinical information, making prenatal recognition of this disorder challenging. In this study, we integrated prenatal and postnatal clinical information from the present case with a pooled analysis of published prenatal Dup15q syndrome cases, providing additional insights into the prenatal-to-postnatal phenotypic spectrum of Dup15q syndrome.Case presentationWe report a case of Dup15q syndrome with both prenatal and postnatal clinical data. Although prenatal ultrasound showed polyhydramnios, an abdominal circumference below the 10th percentile, and mild tricuspid regurgitation, no further prenatal genetic testing was performed. After birth, the patient presented with early hypotonia and developmental delay, and the diagnosis was established by genetic testing after a poor response to rehabilitation. We collected 34 prenatal Dup15q syndrome cases through literature review. The results showed that non-invasive prenatal screening (NIPS) may facilitate the prenatal identification of Dup15q syndrome. Prenatal ultrasound findings included polyhydramnios, fetal growth restriction (FGR), cardiac abnormalities, dysmorphic features, and abnormal ultrasound soft markers. The pooled analysis further provided an overview of the prenatal phenotypic spectrum of Dup15q syndrome and suggested that FGR and polyhydramnios, particularly in the presence of additional ultrasound abnormalities, positive NIPS results, or a positive family history, may warrant further etiological evaluation.ConclusionsDup15q syndrome exhibits prominent clinical heterogeneity with nonspecific prenatal manifestations, predisposing patients to missed or delayed diagnosis. By integrating prenatal and postnatal clinical information with pooled prenatal cases, this study provides a broader understanding of the phenotypic spectrum of Dup15q syndrome and may facilitate prenatal counseling and early clinical recognition.