title: Prenatal diagnosis of partial trisomy 12 and partial trisomy 21 due to a 3:1 segregation of maternal reciprocal translocation t(12;21) (p13.3;q21).
abstract: We describe the prenatal diagnosis and fetal phenotype of partial trisomy 12 (p13.3-pter) and partial trisomy 21 (pter-q21) due to a 3:1 segregation with tertiary aneuploidy transmitted from a maternal reciprocal translocation 12;21. Genetic amniocentesis of a 39-year-old gravida 2, para 1 woman at 19 weeks' gestation due to advanced maternal age revealed an unusual karyotype of 47,XY,+der(21)t(12;21)(p13.3;q21)mat. The pregnancy was terminated at 24 gestational weeks. The proband postnatally displayed by dysmorphic features of a round flat face with prominent cheeks and high forehead, upward slanting palpebral fissures, epicanthic folds, hypertelorism, a short nose, a broad and depressed nasal bridge, anteverted nares, a deformed philtrum, an open mouth, thin upper vermilion and broad everted lower lip, low-set ears with prominent anthelix and deep concha, broad hands with simian creases, a short neck, and cryptorchidism. The association of the involved chromosomal segments with the phenotype of Down's syndrome and trisomy 12p syndrome is discussed.
authors.affiliation: Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China.
authors.forename: C P
authors.initials: CP
authors.lastname: Chen
authors.forename: C C
authors.initials: CC
authors.lastname: Lin
authors.forename: C Y
authors.initials: CY
authors.lastname: Chuang
authors.forename: C C
authors.initials: CC
authors.lastname: Lee
authors.forename: W L
authors.initials: WL
authors.lastname: Chen
authors.forename: S W
authors.initials: SW
authors.lastname: Jan
authors.forename: S P
authors.initials: SP
authors.lastname: Lin
mesh_terms: D000328:Adult; D002881:Chromosomes, Human, Pair 12; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007621:Karyotyping; D010641:Phenotype; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014178:Translocation, Genetic; D014314:Trisomy