Biomaterial Database

Heterokaryotypic pregnancy: monozygotic monochorionic twins discordant for trisomy 13. 2010

Waldo Sepulveda, and Amy E Wong, and Myriam Ocaranza

Maternal-Fetal Medicine Unit, Department of Obstetrics and Gynecology, San Jose Hospital, University of Santiago de Chile, Casilla, Santiago, Chile. fetalmed@yahoo.com

BACKGROUND The occurrence of a discordant chromosomal abnormality in monozygotic twins is an extremely rare condition. METHODS We report the prenatal sonographic findings and cytogenetic studies in a monochorionic twin pregnancy discordant for severe fetal anomalies. Amniocenteses demonstrated heterokaryotypia for trisomy 13 in monozygotic twins. The pregnancy was managed conservatively, resulting in the delivery of discordant twins at 32 weeks. The structurally normal twin survived without sequelae, but the abnormal twin died shortly after delivery. CONCLUSIONS This report adds to the literature the second known case of a spontaneously conceived monochorionic twin pregnancy discordant for trisomy 13 and highlights the necessity of sampling both fetuses in cases of monochorionic twins presenting with discordant structural anomalies.

UI	MeSH Term	Description	Entries
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D002882	Chromosomes, Human, Pair 13	A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.	Chromosome 13
D004200	Diseases in Twins	Disorders affecting TWINS, one or both, at any age.	Diseases in Twin,Twin, Diseases in,Twins, Diseases in,in Twin, Diseases,in Twins, Diseases
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000073839	Trisomy 13 Syndrome	A chromosome disorder associated with TRISOMY of all or part of CHROMOSOME 13. Clinical manifestations include CONGENITAL HEART DEFECTS (e.g., PATENT DUCTUS ARTERIOSUS), facial malformations (e.g., CLEFT LIP; CLEFT PALATE; COLOBOMA; MICROPHTHALMIA); HYPOTONIA, digit malformations (e.g., POLYDACTYLY or SYNDACTYLY), and SEIZURES and severe INTELLECTUAL DISABILITY associated with NERVOUS SYSTEM MALFORMATIONS.	Bartholin-Patau Syndrome,Chromosome 13 Duplication,Chromosome 13 Trisomy Syndrome,Complete Trisomy 13 Syndrome,Mosaic Trisomy 13 Syndrome,Patau Syndrome,Patau's Syndrome,Trisomy 13,Trisomy 13 Syndromes,Bartholin Patau Syndrome,Chromosome 13 Duplications,Duplication, Chromosome 13,Pataus Syndrome
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000649	Amniocentesis	Percutaneous transabdominal puncture of the uterus during pregnancy to obtain amniotic fluid. It is commonly used for fetal karyotype determination in order to diagnose abnormal fetal conditions.	Amniocenteses
D014314	Trisomy	The possession of a third chromosome of any one type in an otherwise diploid cell.	Partial Trisomy,Chromosomal Triplication,Chromosomal Triplications,Partial Trisomies,Trisomies,Trisomies, Partial,Trisomy, Partial
D014430	Twins, Monozygotic	Two off-spring from the same PREGNANCY. They are from a single fertilized OVUM that split into two EMBRYOS. Such twins are usually genetically identical and of the same sex.	Twins, Identical,Identical Twin,Identical Twins,Monozygotic Twin,Monozygotic Twins,Twin, Identical,Twin, Monozygotic