Is classic pericentric inversion of chromosome 2 inv(2)(p11q13) associated with an increased risk of unbalanced chromosomes?

Objective

To study pericentric inversion segregation and interchromosomal effect on sperm for men heterozygous for inv(2)(p11q13), to assess the risk of miscarriage.

Design

Case report.

Setting

Department of reproductive biology, cytogenetics, gynecology, and obstetrics.

Patient(s)

Seven patients heterozygous for inv(2)(p11q13) and five patients with normal karyotype with experience of recurrent spontaneous miscarriage.

Intervention(s)

Fluorescence in situ hybridization on sperm with 2 p and 2q subtelomeric probes to screen for inversion segregation, and X, Y, and 18 centromeric probes to study interchromosomal effects. One thousand sperm were analyzed per experiment and per patient.

Main Outcome Measure(s)

Rate of unbalanced chromosomes and aneuploid sperm.

Result(s)

The inv(2)(p11q13) patients showed a 0.3% rate of sperm with unbalanced chromosomes. For interchromosomal effects, a 0.6% aneuploid sperm rate was observed for patients heterozygous for inv(2)(p11q13). This is similar to the 0.5% rate observed for control patients.

Conclusion(s)

Inv(2)(p11q13) seems not to increase miscarriage for couples with men heterozygous for this inversion.

Key Words: Sperm FISH, inv(2)(p11q13), meiotic segregation, interchromosomal effect (ICE), miscarriage