Clinical and molecular description of a fetus in prenatal diagnosis with a rare de novo ring 10 and deletions of 12.59 Mb in 10p15.3–p14 and 4.22 Mb in 10q26.3

Abstract

Ring chromosomes are rare cytogenetic findings and are mostly associated with an abnormal phenotype. We report on the prenatal diagnosis of a ring chromosome 10 in a fetus in which talipes equinovarus was incidentally found during routine obstetric ultrasound at 22 weeks of gestation. Amniocentesis was undertaken and cytogenetic analysis revealed a de novo non-mosaic apparently stable ring chromosome 10 replacing one of the two homologs. Multiplex Ligation-dependent Probe Amplification (MLPA) revealed subtelomeric deletions in both the short and long arm of chromosome 10. Analysis with high resolution micro-array based comparative genomic hybridization (array-CGH), defined the ring chromosome as del 10p15.3–p14 (12.59Mb in size) and del 10q26.3 (4.22Mb in size) and revealed the genes that are deleted. After elected termination of the pregnancy at 27th week of gestation a detailed autopsy of the fetus allowed for genotype–phenotype correlations. To our knowledge, this is the first case of a de novo ring chromosome 10 which is reported during prenatal diagnosis and is thoroughly investigated with array CGH and autopsy study.