Monochorionic twins with the same blood karyotype of 46,XY/47,XYY but different phenotypes.
We report the case of a 13-year-old woman who was pregnant with phenotypically discordant monochorionic twins: one with cystic hygroma and hydrops, the other one normal. Fetal blood sampling was performed by intrahepatic blood collection for karyotyping of both fetuses, revealing the same genotype of 46,XY/47,XYY in 2:1 proportion. Phenotypic discordance in monozygotic twins can have various causes, such as placental vascular anatomy, differences in allocation of the number of blastomeres or genetic postzygotic events.
Wuttikonsammakit
Piyawadee
P
Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Tanawattanacharoen
Somchai
S
Uerpairojkit
Boonchai
B
D000015:Abnormalities, Multiple / Q000000981:diagnostic imaging* / Q000235:genetics; D000293:Adolescent; D004200:Diseases in Twins / Q000097:blood / Q000000981:diagnostic imaging / Q000235:genetics*; D005260:Female; D005312:Fetal Blood; D005313:Fetal Death; D006061:Gonadal Dysgenesis, 46,XY / Q000097:blood; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007621:Karyotyping; D050498:Live Birth; D008297:Male; D010641:Phenotype; D011247:Pregnancy; D014430:Twins, Monozygotic / Q000097:blood / Q000235:genetics*; D016216:Ultrasonography, Prenatal; D014997:XYY Karyotype / Q000097:blood