First case of trisomy 13 plus mosaic trisomy 1q.

OBJECTIVES

In a case with severe sonographic abnormalities followed by missed abortion in week 14 + 5 days, cytogenetic analysis was performed on placental tissue. A mosaic karyotype 47,XY,+13,add(1)(q44)[3]/47,XY, +13[9]/46,XY[36] was detected. The purpose of the present study was to characterize the additional material on chromosome 1q.

METHODS

According to GTG banding, the additional material on chromosome 1 was most probably chromosome 1 material. Thus, multicolor banding analysis using a chromosome 1 specific probe set was done to precisely describe the rearranged chromosome 1.

RESULTS

Molecular cytogenetic approaches revealed that the derivative chromosome 1 was der(1)(1p36.3-->1q44::1q12-->1q44).

CONCLUSIONS

This is the first description of a case with a trisomy 13 plus a partial trisomy 1q presenting with clinical signs of both aberrations. Moreover, the multicolor banding technique is suited to resolve complex karyotypes in the prenatal diagnosis, i.e., chromosome preparations of fibroblasts.