Genes associated with the genesis of leiomyoma of the uterus in a commonly deleted chromosomal region at 7q22.

Uterine leiomyoma occurs in about 20-30% of women over the age of 30, and is the most frequent benign tumor in gynecology. Despite its benign status, leiomyoma of the uterus has been reported to involve chromosomal abnormalities on chromosome 7. To search for genes associated with the genesis and development of this disease, we examined microsatellite alterations on chromosome 7 in 41 uterine leiomyomas, and identified a commonly-deleted region. Allelic imbalance on chromosome 7 was detected with an incidence of 7% (3/41), with the D7S501 locus being the most frequently affected (13%). The commonly deleted region was between D7S2545 and D7S2420. We examined alterations in the expression of genes located within this region by RT-PCR. Only the LAMB1 (Laminin beta1) gene showed a variable expression. Of the 21 cases, 12 showed an increase, and 5 (24%) a decrease in the expression of LAMB1 in the leiomyomatous region. These results suggested that alteration of LAMB1 expression is associated with the genesis and development of uterine leiomyoma.