Clinical characteristics and genetic counseling for a three-generation Chinese pedigree with recurrent fetal Kabuki syndrome due to variant of KDM6A gene

Abstract

To explore the genetic basis for a pregnant woman with a history of adverse pregnancy outcomes. A woman with an adverse history of pregnancies including one fetal demise and two induced abortions due to fetal diaphragmatic hernia and complex cardiac anomalies was selected as the study subject. Muscle tissue from the induced abortus was subjected to whole exome sequencing, and candidate variant was verified by Sanger sequencing of the couple and other family members. Genetic sequencing revealed that the fetus has harbored a frameshift variant of the KDM6A gene (NM_001291415.2), namely c.1228_1229del (p.Gln410GlufsTer2), which was inherited from the woman and her mother. The variant was unreported previously, and the woman was found to have short stature, sparse eyebrows in the outer third, peculiar facial features, but normal intelligence in addition with female congenital genital malformation, like incomplete vaginal septum, double cervix, double uterus, and unilateral ovary absence. mostly similar phenotypes observed in her mother. The hemizygous c.1228_1229del variant of the KDM6A gene probably underlay the abnormalities in the fetus. All findings have enabled genetic counseling for this family featuring X-linked inheritance, and the woman had given birth to a healthy girl with appropriate prevention and intervention.