Prenatal detection of a subtle unbalanced chromosome rearrangement by karyotyping, FISH and array comparative genomic...

To explore the advantages and limitations of comparative genomic hybridization to BAC arrays (array CGH) for prenatal diagnosis of a fetus with anomalies and a chromosome abnormality.

We used karyotype analysis, FISH and array CGH to investigate an unbalanced chromosome rearrangement.

We report a case of a fetus with ultrasound anomalies at 11 weeks' gestation and an unbalanced chromosome translocation [46,XX,der(13)t(2;13)(p25.1;q32)pat]. Initially, a chromosome 13 deletion was reported from G-banded chromosome analysis and 13q subtelomere FISH. The involvement of chromosome 2 was determined after a balanced translocation was identified in the father, 46,XY,t(2;13)(p25.1;q32). Array CGH confirmed the fetal abnormality as partial trisomy of the short arm chromosome 2 and partial monosomy of the long arm of chromosome 13. The abnormalities identified by ultrasound studies and autopsy appear to be most consistent with 13q deletion syndrome.

Array CGH successfully identified a subtle unbalanced chromosome complement in a fetus with multiple ultrasound anomalies. If array CGH had been performed along with the fetal karyotype, the cryptic partial trisomy 2 could have been identified in a more timely manner to assist in the prenatal counseling of this family.