Population studies of inv(9) chromosomes in 4,300 japanese: Incidence, sex difference and clinical significance

Abstract

SummaryPopulation incidence of a chromosome 9 with an inversion of qh, inv(9), was surveyed using C-banding in a total of 4,367 Japanese which consisted of five patient groups and a normal control group. The inv(9) incidence was 1.65~ in the normal control group (n=1,513) and 1.52~ in the Down syndrome patient group (n----1,246). The incidence of female carriers was 1.7 times higher than that of male carriers in the above two groups. The sex difference was significant (p<0.05). Moreover, the incidence in the 47,XXY male group (n~277) was slightly higher than female carrier incidences. The excess of carriers about 2 times was observed in the habitual abortion couple group (n~--694) and the spontaneous abortus group (n=181), both having normal karyotypes. The present data probably indicate the existence of a genetic effect of inv(9) on human reproductive performance, while they could not explain the sex difference found in inv(9) carriers. Our speculation for the sex difference has been presented.

Acquired pericentric inversion of chromosome 9 in essential thrombocythemia

“…Among them, there were 27 cases (1.2%) of proven constitutional inv(9)(p11q13) on karyotyping of bone marrow cells. This was in keeping with the quoted incidence of pericentric inversion of chromosome 9, namely 1.0-1.7% in the Oriental population (Ko et al 1992;Yamada 1992;Teo et al 1995) and 0.9% in the Caucasian population (Tawn and Earl 1992). As pericentric inversion of chromosome 9 is not over-represented in patients with hematological malignancies, there is no evidence from our data to suggest that the presence of constitutional inv(9qh) increases the risk of hematological malignancies.…”

Linear increase of structural and numerical chromosome 9 abnormalities in human sperm regarding age

“…Unfortunately, this excess of X-bearing sperm could result from an underestimation of X chromosome nullisomy due to the absence of the X chromosome probe in this study. Nevertheless, in an epidemiological study of 4300 individuals from Japan, 25 the incidence of inv (9) carriers was about two times higher in the female group than in the male group (Po0.05).…”

Behavioral and Developmental Characteristics of Children with Inversion of Chromosome 9 in Korea: A Preliminary Study

“…There is a possibility that chromosomal rearrangement could interrupt the function of one or more genes close to the breakpoint. Several reports [4][5][6] suggesting that there may be a susceptibility gene for schizophrenia located at the breakpoints of inv (9), and other reports suggesting the existence of an association between inv(9) and recurrent abortions or infertility 10,11,[24][25][26] can be understood in this context.…”

“…Serra et al 8 estimated the incidence to be 0.85% among newborn infants in European populations, while Hsu et al 13 reported that the incidence differed between ethnic groups, and was lowest in Asian populations (0.26%). However, Yamada, 11 Ko et al 14 and Teo 15 analyzed the data from several Asian countries, and reported the incidence of inv (9) in the Asian population to be 1.65%, 1.20% and 1.20%, respectively. The incidences were lower in several countries, such as Taiwan and Singapore, but methodological differences might have influenced the results, as some of the studies involved were based on the analysis of newborns, while others were based on antenatal cytogenetic analysis.…”

“…However, the association of inv (9) with psychiatric disorders such as schizophrenia, 4-6 bipolar disorder, 7 mental retardation 8 and personality disorder 9 has been reported, and there have been several reports of its association with congenital urological anomalies such as undescended testes or hermaphroditism, and there have been many studies which reported recurrent spontaneous abortions or infertility in obstetric patients with inv (9), for whom there was no other apparent reason for such conditions. 2,10,11 In addition, a recent report posits the existence of various phenotypes of inv(9) depending on the differential breakpoint. 12 The incidence of inv (9) in the normal population has been found to differ from country to country.…”