Cardiac malformation of partial trisomy 7p/monosomy 18p and partial trisomy 18p/monosomy 7p in siblings as a result of reciprocal unbalanced malsegregation--and review of the literature.

We report two unbalanced translocations involving the short arms of chromosomes 7 and 18 due to a balanced translocation 7;18 in the mother. Karyotyping and fluorescence in situ hybridization analysis of the female fetus revealed an unbalanced subtelomeric translocation(karyotype 46,XX,der(18)t(7;18)(p22.3;p11.32)mat resulting in a partial trisomy 7p and a partial monosomy 18p.Array comparative genomic hybridization (CGH) detected a4.44-Mb heterozygous duplication at 7p22.3 to 7p22.1 and a0.178-Mb heterozygous deletion at 18p11.32. Clinical characteristics comprised a mildly stenotic bicuspid aortic valve and a small aortic arch without coarctation. The patient's older brother displayed a reciprocal version of her chromosomal aberration (46,XY,der(7)t(7;18)(p22;p11.32) resulting in a partial monosomy 7p and a partial trisomy 18p. Array CGH revealed a 4.75-Mb heterozygous deletion at 7p22.3p22.1 and a 0.579-Mb duplication at 18p11.32. He presented with tetralogy of Fallot, cleft palate, microcephalus without craniosynostosis, growth retardation, ptosis of the right eyelid, right-sided renal agenesis, unilateral cryptorchism,and mental retardation. In this report, we present the clinical phenotype in patients with aberrations of chromosomes 7p and 18p and reviewed the literature to summarize cardiovascular malformations in these patients.