Tetrasomy 18p in a Twin Pregnancy with Diverse Expression in Both Fetuses.
Tetrasomy 18p, characterized by the presence of four copies of the short arm of chromosome 18, is considered to occur with the nondisjunction in meiosis II after the errors in the meiotic and early postmeiotic mitotic division in the centromere. It is accompanied by various abnormalities including congenital heart defects, lower extremity abnormalities, micrognathia, high arched palate, kyphoscoliosis, microcephaly, myelomeningocele, hernia and renal anomalies. We present the first case of a dichorionic diamniotic twin pregnancy in which both fetuses were affected by tetrasomy 18p, but with discordant morphology, detected in one twin in the first but in the other in the second trimester.
a Division of Perinatology, Faculty of Medicine , Department of Obstetrics & Gynecology , Trakya University , Edirne , Turkey.
Cihan
C
Inan
a Division of Perinatology, Faculty of Medicine , Department of Obstetrics & Gynecology , Trakya University , Edirne , Turkey.
N Cenk
NC
Sayın
b Department of Medical Genetics , Faculty of Medicine, Trakya University , Edirne , Turkey.
Emine
E
Atlı
b Department of Medical Genetics , Faculty of Medicine, Trakya University , Edirne , Turkey.
Selma
S
Ulusal
a Division of Perinatology, Faculty of Medicine , Department of Obstetrics & Gynecology , Trakya University , Edirne , Turkey.
Selen
S
Erzincan
a Division of Perinatology, Faculty of Medicine , Department of Obstetrics & Gynecology , Trakya University , Edirne , Turkey.
Isil
I
Uzun
b Department of Medical Genetics , Faculty of Medicine, Trakya University , Edirne , Turkey.
Hakan
H
Gurkan
a Division of Perinatology, Faculty of Medicine , Department of Obstetrics & Gynecology , Trakya University , Edirne , Turkey.
Füsun G
FG
Varol
D059786:Abnormal Karyotype; D000015:Abnormalities, Multiple / Q000235:genetics / Q000473:pathology*; D000328:Adult; D000782:Aneuploidy; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics; D005260:Female; D006801:Humans; D011247:Pregnancy; D059285:Pregnancy, Twin; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal
monozygotic twins; prenatal diagnosis; tetrasomy 18p