Acrocentric chromosome polymorphisms: beware of cryptic translocations.
Cryptic translocations may escape diagnosis, especially when they implicate chromosomal regions that are known to be polymorphic in the human karyotype. We describe a case of postnatal diagnosis of Beckwith-Wiedemann syndrome (BWS) due to an unbalanced translocation that had not been diagnosed in the fetal karyotype. This first cytogenetic analysis revealed that one chromosome 14 presented as a common acrocentric short arm polymorphism. Further analyses after birth, using C-banding, NOR staining and fluorescence in situ hybridization (FISH) with telomeric probes, revealed that it was the result of an unbalanced de novo t(11;14)(p15;p13) translocation leading to partial 11p trisomy and to BWS. Prenatal cytogenetic management of such apparently inoffensive chromosome markers is discussed.
Benzacken
B
B
Service d'Histologie, Embryologie, Cytogénétique et Biologie de la Reproduction, Hôpital Jean Verdier, 93 Bondy, France.
Monier-Gavelle
F
F
Siffroi
J P
JP
Agbo
P
P
Chalvon
A
A
Wolf
J P
JP
D000328:Adult; D001506:Beckwith-Wiedemann Syndrome / Q000175:diagnosis* / Q000235:genetics*; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002880:Chromosomes, Human, Pair 11; D002883:Chromosomes, Human, Pair 14; D004396:Coloring Agents; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009697:Nucleolus Organizer Region / Q000648:ultrastructure; D011110:Polymorphism, Genetic; D011247:Pregnancy; D014178:Translocation, Genetic; D014314:Trisomy
D004396:Coloring Agents