Association of pericentric inversion of chromosome 9 and infertility in romanian population.

Background: One of the most common structural balanced chromosome rearrangements is pericentric inversion of chromosome 9; inv(9)(p11q12), which is consider to be the variant of normal karyotype and has been found in normal population. Although it seems not to correlate with abnormal phenotypes, there have been many controversial reports indicating that it may lead to abnormal clinical conditions such as infertility and recurrent abortions. The incidence is found to be about 1% - 3% in the general population. The aim of this study was to re-evaluate the clinical impact of inv(9)(p11q12)/(p11q13) in infertility.

Materials And Methods: We investigated the karyotypes of 900 infertile couples (1800 individuals) admitted in our hospital for cytogenetic analysis. The control group consists of 1116 fetuses investigated by amniocentesis. This group was considered to be a sample of the fertile population, as the fetus being karyotyped is the result of a spontaneous pregnancy. Fetal karyotyping was made according to the standard indications for prenatal diagnosis (abnormal maternal serum screening results). Chromosomes from cultured peripheral blood lymphocytes and amniotic fluid were analyzed using Giemsa Trypsin-Giemsa (GTG) banding. The results of the two groups were compared.

Results: 1800 infertile people were submitted for cytogenetic investigation. In the control group 97.73% had normal karyotype and 2.27% showed inversion of chromosome 9, while in the studied group 96.24% had normal karyotype and 3.76% showed inversion of chromosome 9. The incidence of inversion 9 in both male and female patients is not significantly higher comparing with normal population (p = 0.343, p< 0.05).

Conclusions: Because a considerable proportion of patients with reproductive dysfunction had various cytogenetic abnormalities, the chromosomal analysis should be considered as a diagnostic tool in the evaluation of reproductive dysfunction (infertility in men due to spermatogenic disturbances and in recurrent spontaneous abortion in females).