Ring chromosome 3, r(3), is an extremely rare cytogenetic abnormality with clinical heterogeneity and only 12 cases reported in the literature. Here, we report a 1-year-old girl presenting distinctive facial features, developmental delay, and congenital heart defects with r(3) and a ∼10-Mb deletion of chromosome 3pterp25.3 (61,891-9,979,408) involving 42 known genes which was detected using G-banding karyotyping and CytoScan 750K-Array. The breakpoints in r(3) were mapped at 3p25.3 and 3q29. We also analyzed the available information on the clinical features of the reported cases with r(3) and 3p deletion syndrome in order to provide more valuable information of genotype-phenotype correlations. To our knowledge, this is the largest detected fragment described in r(3) cases and the second r(3) study using whole-genome microarray.
Disruption of Contactin 4 (CNTN4) Results in Developmental Delay and Other Features of 3p Deletion Syndrome