Background: Chromosome 1p36 deletion syndrome is a contiguous genetic disorder with multiple congenital anomalies and mental retardation. It has been emerging as one of the most common terminal deletion syndromes in humans with the rapid utility of microarray analysis. However, the prenatal findings of 1p36 deletion syndrome are still limited. We report a fetus with 1p36 deletion and cardiac phenotype of dextrocardia, combined with a balanced translocation between chromosome 5 and 6. The phenotype of dextrocardia is rarely reported in prenatal 1p36 deletion cases.
Case presentation: We present a prenatal 1p36 deletion case with congenital heart diseases and single umbilical artery. Fetal echocardiography showed dextrocardia, ventricular septal defect and pericardial effusion. Fetal karyotype revealed a de novo balanced translocation of 46,XY,t(5;6)(q11.2;q23.3). Chromosomal microarray analysis detected a pathogenic deletion in 1p36.21p36.12, with the size of 6.38 Mb. Further whole genome sequencing revealed that the balanced translocation disrupted the EYA4 and ITGA1 genes.
Conclusions: Although congenital heart diseases are very common clinical manifestations among patients with 1p36 deletion, dextrocardia is a quite rare cardiac phenotype. This is the second case with 1p36 deletion and dextrocardia, and the first prenatally diagnosed 1p36 deletion case with dextrocardia. Our case indicates that genes in 1p36 are associated with not only heart structural anomalies, but also cardiac laterality development. Our results also imply that the EYA4 gene disrupted by the balanced translocation might be related with the cardiac development.
Keywords: 1p36 deletion syndrome; Chromosomal microarray analysis; Isolated dextrocardia; Prenatal diagnosis; Whole genome sequencing.