Am J Perinatol 1983; 1(1): 81-88
DOI: 10.1055/s-2007-1000058
ORIGINAL ARTICLE

© 1983 by Thieme Medical Publishers, Inc.

Clinical Implications of Chromosomal Inversions

A Pericentric Inversion in No. 18 Segregating in a Family Ascertained Through an Abnormal ProbandAlice O. Martin1 , Joe Leigh Simpson1 , Ruth B. Deddish2 , Sherman Elias1
  • 1Department of Obstetrics and Gynecology, Northwestern University Medical School and Northwestern Memorial Hospital, Chicago, Illinois
  • 2Department of Pediatrics, Northwestern University Medical School and Northwestern Memorial Hospital, Chicago, Illinois
Further Information

Publication History

Publication Date:
04 March 2008 (online)

ABSTRACT

Chromosomal inversions are being detected in humans with increasing frequency due to the application of chromosomal banding techniques. Inversions have occurred in all chromosomal groups. These structural aberrations may lead to infertility, reproductive loss, or abnormal offspring. To illustrate their clinical significance, we report a family in which an inversion in chromosome No. 18 is segregating. This family was ascertained through a proband whose anomalies were consistent with the deletion 18q syndrome. The chromosomal imbalance originated by recombination within the parental inversion during meiosis. Consideration of this family and 6 others with similar breakpoints (18p11 and 18q12 or q21) suggests that the risk of unbalanced (recombinant) livebirths may be higher for female inv (18) heterozygotes than for males. The paucity of male carriers detected could be due to prenatal selection or chance. Overall, there may be preferential segregation for the aberrant chromosomes (inversions plus recombinants). Amniocentesis and cytogenetic analysis of pregnancy losses is recommended for families in which inversions are detected.

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