Triple trisomy in a spontaneous abortion

Double and multiple chromosomal aneuploidies in spontaneous abortions: A single institutional experience

OBJECTIVE:

To characterize double and multiple aneuploidies in spontaneous abortions (SAB).

MATERIALS AND METHODS:

Retrospective analysis of cytogenetics data obtained by culturing/harvesting products of the conception material at our center from 2006 to 2009 was performed. The abnormal cytogenetic results, maternal age, gestational age, and previous pregnancy history were recorded and compared.

RESULTS:

Double and multiple aneuploidies are rare, however, a high percentage of double (4.6%) and multiple (0.4%) chromosomal aneuploidies were observed in our study of 1502 cases of SAB. Of 1502 cases of SAB evaluated, 70 cases (4.6%) showed double aneuploidy, whereas 6 cases (0.4%) had multiple aneuploidies. The chromosomes most frequently involved in double aneuploidy in the decreasing order were 21, 16, ± X, 22, 18, 13, and 15. The most frequent chromosome combinations observed were: Loss of X/21 (8.5%), 21/22 (4.4%), 16/21 (4.4%), and 7/16 (4.4%). The chromosome combinations in multiple aneuploidy included trisomy of chromosomes X/5/8, 8/20/22, 16/20/22, 14/21/22, and loss of X with 21/21 and 7/21. These abnormalities were significantly observed in women between the age group 40-44 years (59.2%). A high success rate (94%) of obtaining metaphase cells was observed in this study mainly due to the use of direct and long-term cultures.

CONCLUSIONS:

We observed a high percentage of double (4.6%) and multiple (0.4%) aneuploidies, frequently involving the acrocentic chromosomes 13, 15, 21, and 22 and nonacrocentric chromosomes X, 16, and 18.

Rapid prenatal diagnosis of 14 cases of triploidy using fish with multiple probes

Fluorescence in situ hybridization (FISH) of chromosome-specific probes to interphase nuclei can rapidly identify aneuploidies in uncultured amniotic fluid cells. Using DNA probe sets specific for chromosomes 13, 18, 21, X, and Y, we have identified 14 fetuses where the hybridization pattern was consistent with a triploid chromosome constitution. In each case, the identification of fetal abnormalities by ultrasound examination initiated a request for rapid determination of ploidy status via prenatal FISH analysis of uncultured amniocytes. FISH produced a three-signal pattern for the three autosomes in combination with signals indicating an XXX or XXY sex chromosome complement. This hybridization pattern was interpreted to be consistent with triploidy. Results were reported to the physician within 2 days of amniocentesis and subsequently confirmed by cytogenetics. These cases demonstrate the utility of FISH for rapid prenatal identification of triploidy, particularly when fetal abnormalities are seen with ultrasonographic examination.