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Tetrasomy 13q31.1qter due to an inverted duplicated neocentric marker chromosome in a fetus with multiple malformations
Author(s) -
Haddad Véronique,
Aboura Azzedine,
Tosca Lucie,
Guediche Narjes,
Mas AnneElisabeth,
L'Herminé Aurore Coulomb,
Druart Luc,
Picone Olivier,
Brisset Sophie,
Tachdjian Gérard
Publication year - 2012
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.35258
Subject(s) - tetrasomy , biology , karyotype , chromosomal inversion , fluorescence in situ hybridization , comparative genomic hybridization , marker chromosome , centromere , genetics , chromosome , gene
Small supernumerary marker chromosome (sSMC) lacking alpha satellite DNA or endogenous centromere regions are rare and contain fully functional centromeres, called neocentromeres. We report on a woman with a 14‐week gestation pregnancy with a cystic hygroma and cerebellar hypoplasia at ultrasound examination. Cytogenetic studies showed a karyotype 47,XY,+mar dn. This sSMC was observed in chorionic villi, lung, and muscle tissue. Array Comparative Genomic Hybridization showed a gain from 13q31.1 to 13qter region. Fluorescent in situ hybridization with pan alpha satellite probe and probes specific for chromosome 13 showed a marker corresponding to an inversion duplication of the 13q distal chromosomal region without alpha satellite DNA sequence, suggesting the presence of a neocentromere. Examination of the fetus showed dysmorphic features, cystic cervical hygroma, postaxial polydactyly of the right hand and left foot with short fingers, malrotation of the gut, and a micropenis with hypospadias. Genotype–phenotype correlation in tetrasomy 13q is discussed according to the four 13q chromosomal breakpoints reported (13q32, 13q31, 13q21, 13q14) for chromosome 13 supernumerary markers. © 2012 Wiley Periodicals, Inc.