Prenatal diagnosis and molecular cytogenetic characterization of mosaic ring chromosome 13.
We present prenatal diagnosis and molecular cytogenetic characterization of de novo mosaic r(13). A 32-year-old woman underwent amniocentesis at 18 weeks of gestation because of maternal anxiety. Amniocentesis revealed a karyotype of 46,XY,r(13)[33]/45,XY,-13[19]. aCGH on uncultured amniocytes at repeated amniocentesis detected a 4.22-Mb deletion at 13q34. Interphase FISH on 100 uncultured amniocytes showed the ratio of r(13):-13:idic r(13) as 85%:13%:2%. The cord blood had a karyotype of 46,XY,r(13)[91]/46,XY,idic r(13)[6]/45,XY,-13[3]. The placenta had a karyotype of 46,XY,mar(13)[31]/45,XY,-13[3]. Metaphase FISH confirmed that the marker chromosomes in placenta were derived from chromosome 13. aCGH on cultured placental cells detected a 77.81-Mb deletion at 13q13.3-q34. The fetus postnatally manifested facial dysmorphism. Prenatal diagnosis of r(13) should alert mosaicism for deletion/duplication of r(13) and distal 13q deletion. Fetoplacental chromosomal discrepancy of r(13) may exist in case of mosaic r(13) detected by amniocentesis.
Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang-Ming University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: cpc_mmh@yahoo.com.
Chih-Ping
CP
Chen
Chin-Han
CH
Tsai
Schu-Rern
SR
Chern
Peih-Shan
PS
Wu
Jun-Wei
JW
Su
Chen-Chi
CC
Lee
Yu-Ting
YT
Chen
Wen-Lin
WL
Chen
Li-Feng
LF
Chen
Wayseen
W
Wang
D000328:Adult; D000649:Amniocentesis / Q000379:methods*; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics* / Q000378:metabolism; D055028:Comparative Genomic Hybridization / Q000379:methods; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D059785:Karyotype; D009030:Mosaicism; D011247:Pregnancy; D012303:Ring Chromosomes
AFP; Amniocentesis; CNS; FISH; Fetoplacental chromosomal discrepancy; Marker chromosome; Mosaicism; OMIM; Online Mendelian Inheritance in Man; Ring chromosome 13; aCGH; array comparative genomic hybridization; central nervous system; del; deletion; fluorescence in situ hybridization; idic; isodicentric chromosome; mar; marker chromosome; r; ring chromosome; uE3; unconjugated estriol; α-fetoprotein; β-hCG; β-human chorionic gonadotrophin