Prenatal sonographic features of Alagille syndrome: a single-center experience

Introduction Alagille syndrome (ALGS) is a rare autosomal dominant multisystem condition. This study focuses on the prenatal sonographic findings observed in cases confirmed to have ALGS through the molecular detection of JAG1 variants, either prenatally or postnatally. Methods This retrospective study enrolled thirteen cases of ALGS, diagnosed either prenatally or postnatally. Comprehensive medical records were systematically reviewed, with emphasis on pregnancy-related data, including serial fetal ultrasound examinations throughout gestation, molecular genetic test results, and pregnancy outcomes. Results Among the thirteen cases, ten demonstrated abnormal sonographic findings during the second trimester: unilateral multicystic dysplastic kidney (MCDK) in two (2/13), left MCDK with concomitant right renal agenesis in one (1/13), left MCDK associated with butterfly vertebrae in one (1/13), isolated butterfly vertebrae in three (3/13), non-visualized gallbladder in two (2/13), and supravalvular aortic stenosis with persistent left superior vena cava in one (1/13). The remaining three cases exhibited normal second-trimester ultrasound examinations but developed abnormal sonographic features in the third trimester: intrauterine growth restriction (IUGR) was identified in two cases (2/13), and one case showed co-occurring pulmonary artery stenosis and butterfly vertebrae (1/13).Conclusion This study demonstrates that individuals with ALGS lack definitive prenatal ultrasound markers. When abnormalities are present, they are often subtle and nonspecific, which may not prompt clinicians to pursue genetic testing.