A novel JAG1 frameshift variant causing Alagille syndrome with incomplete penetrance

We report a novel frameshift variant of JAG1 in the prenatal setting, associated with Alagille syndrome1 with incomplete penetrance in a Chinese family.A pregnant woman was referred to our center due to fetal cardiovascular abnormality. Whole exome sequencing was employed for this family. A novel heterozygous maternal-origin frameshift variant c.1794_1797del in JAG1 was identified in the fetus. The mother and the fetus had the identical variant, but they demonstrated different clinical manifestations. The fetus was diagnosed with Alagille syndrome 1.A novel frameshift variant in JAG1 was detected in a fetus diagnosed with Alagille syndrome 1, and it showed incomplete penetrance in the family.