20p chromosome inverted duplication syndrome with phenotypes of congenital heart disease, anorectal malformation and megacolon.

20p chromosome inverted duplication deletion syndrome is a rare chromosomal disorder in which the short arm segment 20p11.2-p13 and the deleted subtopic region 20p13-20 replicate simultaneously. Patients with this syndrome are mainly presented with intellectual disability and motor development delay. We report here a middle childhood case of this syndrome characterised by intellectual disability, backward movement, unique facial features, congenital heart disease: ventricular septal defect, patent foramen ovale, pulmonary hypertension and congenital anorectal malformation. The patient's chromosome karyotyping analysis showed a short arm duplication on chromosome 20, described as 46, XY, 20p+?; his parents' karyotyping analysis is normal. Later genotype analysis by array-single nucleotide polymorphisms identified a total of 107 genome-wide copy number variations and we detected a new 1.3 Mb deletion (chr20:63 244-1 349 002) and 20.2 Mb duplication (chr20:1 608 108-24 174 965) from 20p13 to 20p11.2 using infinium asian screening array-24 V1.0 BeadChip (Illumina Inc., San Diego, USA).