%0 Case Reports
%T Prenatal diagnosis of recurrent mosaic ring chromosome 13 of maternal origin.
%A Chen CP
%A Chen CY
%A Chern SR
%A Chen SW
%A Wu FT
%A Chen WL
%A Lee MS
%A Wang W
%J Taiwan J Obstet Gynecol
%V 60
%N 4
%D Jul 2021
%M 34247823
%F 1.944
%R 10.1016/j.tjog.2021.05.033
%X <B>OBJECTIVE: </B>We present prenatal diagnosis of recurrent mosaic ring chromosome 13 [r(13)] of maternal origin.<BR><B>METHODS: </B>A 27-year-old woman underwent amniocentesis at 17 weeks of gestation because of a past history of fetal abnormality caused by mosaic r(13) in the previous fetus associated with fetal intrauterine growth restriction (IUGR), a karyotype of 46,XY,r(13)[23]/45,XY,-13[10]/46,XY,idic r(13)[2] and a maternal origin of abnormal r(13). The parental karyotypes were normal. During this pregnancy, amniocentesis revealed a karyotype of 46,XX,r(13)[12]/45,XX,-13[8] and a 22.80-Mb deletion of chromosome 13q31.3-q34. The pregnancy was subsequently terminated, and a malformed fetus was delivered with craniofacial dysmorphism. Repeat amniocentesis revealed a karyotype of 46,XX,r(13)(p11.1q31)[18]/45,XX,-13[12]. The placenta had a karyotype of 46,XX,r(13)(p11.1q31)[27]/45,XY,-13[13]. Polymorphic DNA marker analysis using the DNA derived from the parental bloods and umbilical cord confirmed a maternal origin of the abnormal r(13).<BR><B>CONCLUSIONS: </B>Prenatal diagnosis of mosaic r(13) in consecutive pregnancies should raise a suspicion of parental gonadal mosaicism, and polymorphic DNA marker analysis is useful for determination of the parental origin of recurrent aneuploidy under such a circumstance.