Mosaic tetrasomy 8q: inverted duplication of 8q23.3qter in an analphoid marker.
We observed an analphoid marker chromosome stable through cell division in a 16-year-old girl with developmental delay, short stature, limb contractures, and ovaries containing multiple cysts. She also developed myasthenia gravis at 15 years. The marker chromosome, present in 75% of metaphases (and in 90% of transformed lymphoblastoid cells), was C-band negative, and had no pan alpha-satellite sequences detectable by fluorescence in situ hybridization (FISH). The 8q origin of the marker was determined by use of subtelomeric probes and was confirmed by chromosome 8 painting probes. The marker was shown to be an inversion duplication of 8q when subtelomeric, telomeric, and c-myc FISH probes hybridized to both ends of the marker. The karyotype was 47,XX,+inv dup(8)(qter--> q23.3::q23.3-->[neocen]-->qter), resulting in tetrasomy for 8q23.3qter. The parents had normal karyotypes. Centromeric proteins CENP-C and CENP-E were present, but alpha associated centromere protein CENP-B was absent at a position defining a neocentromere.
Reddy
K S
KS
Cytogenetics Laboratory, Quest Diagnostics Inc., San Juan Capistrano, California, USA. reddyk@questdiagnostics.com
Sulcova
V
V
Schwartz
S
S
Noble
J E
JE
Phillips
J
J
Brasel
J A
JA
Huff
K
K
Lin
H J
HJ
D000015:Abnormalities, Multiple / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000782:Aneuploidy; D001324:Autoantigens; D002503:Centromere / Q000235:genetics; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics; D002871:Chromosome Banding; D007446:Chromosome Inversion; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D003286:Contracture; D004276:DNA, Satellite; D004268:DNA-Binding Proteins; D005121:Extremities; D005260:Female; D020440:Gene Duplication; D005819:Genetic Markers; D006130:Growth Disorders; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009030:Mosaicism; D010053:Ovary / Q000473:pathology
D001324:Autoantigens; C497926:CENPB protein, human; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone; D004276:DNA, Satellite; D004268:DNA-Binding Proteins; D005819:Genetic Markers; C060905:centromere protein C; C068688:centromere protein E