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.
Service d'Histologie, Embryologie, Cytogénétique et Biologie de la Reproduction, Hôpital Jean Verdier, 93 Bondy, France.
B
B
Benzacken
F
F
Monier-Gavelle
J P
JP
Siffroi
P
P
Agbo
A
A
Chalvon
J P
JP
Wolf
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