Clinical presentation and genotype-phenotype correlation of a novel pure duplication of 6p25.2-p22.3: a case report and literature review.

Abstract

Duplication of 6p is a rare genetic syndrome of which about 25% have one or more congenital cardiac defects including cardiac septal defects, pulmonary artery hypoplasia and patent ductus arteriosus. We present the first case of a fetus with functional single ventricle and persistent truncus arteriosus during prenatal diagnosis whose genomic analysis revealed a novel pure duplication of 6p25.2-p22.3. The duplication fragment was confirmed to be associated with intrachromosomal insertion from mother via chromosome karyotype. The presentation of this case aims to expand the existing knowledge regarding this rare condition and facilitate its diagnosis in the future. Based on the comparison of cases with 6p duplication syndrome, we notice that the 6p terminal region, especially at 6p25.1 to 6p25.2, could be the critical region associated with heart complications or anomalies of the pulmonary arteries. The duplication of the potential modifier genes, RIPK1 and FARS2, were proposed to be attributed to heart defects in our study and should be further researched.