Incidence and Karyotypes According to Each Chromosome in 13 Cases with Inversion

Chung, Sung Ro

Abstract

PURPOSE
This study was aimed to evaluate the incidence and karyotypes according to chromosome in 13 cases with inversion detected by cytogenetic analysis.
METHODS
The incidence of inversion was calculated and karyotypes of inversion were classified according to each chromosome in cases with inversion detected from 390 individuals who had undergone cytogenetic analysis in Hanyang University Hospital from January 2005 to February 2009.
RESULTS
The overall incidence of inversions was 3.3% (13/390). All of 13 cases were heterozygotes for inversions. Among these 13 inversions, 12 cases (92.3%) were having pericentric inversions showing karyotypes of 46,XX,inv(9)(p11q13) in 7 cases, 46,XX,inv(9)(p11q12) in 2 cases, and one cases of 46,X, inv(Y)(p11.3q11.23), t(8;9)(q24.3;q34.1), 46,X, del(Y)(q12), inv(Y)(p10q11. 23) and 46,XY, inv(8)(p21q24.1) respectively. Last one case (7.7%) was having paracentric inversion showing a karyotype of 46,XX,inv(9)(q22.1q34.3). Classification according to each chromosome in 13 cases with inversion was that 10 of 13 cases (76.9%) were located in chromosome 9 (9 cases of pericentric inversions and a case of paracentric inversions), 2 of 13 cases (15.4%) in chromosome Y and 1 of 13 cases (7.7%) in chromosome 8.
CONCLUSION
Although patients are phenotypically normal, they might be inversion carriers. In high risk patients, inversions are more frequent than normal population. Various types of inversion could be in different chromosomes. Classification of types of inversion are needed for further genetic counseling according to the types.