Growth retardation and congenital heart disease in a boy with a ring chromosome 6 of maternal origin.

Background: Rare chromosomal structural abnormalities, including ring chromosomes, often pose challenges to clinical genetic counselling.

Results: Here, we report a newborn with congenital heart disease and developmental delay who inherited ring chromosome 6 [46,XY,r(6)(p25q27)mat] from a phenotypically normal mother. Genotypes and phenotypes were analysed by molecular cytogenetic analysis, whole-exome sequencing and literature review.

Conclusions: Our study showed that the pathogenicity of the ring chromosome abnormality [r(6)(p25q27)] was mainly affected by chromosome imbalance, deletions of genes with haploinsufficiency, duplications of genes with triple sensitivity, parental inheritance of the imbalance and the imprinting status of the affected genes.