Mosaic tetrasomy 8q: Inverted duplication of 8q23.3qter in an analphoid marker

✍ Scribed by Reddy, Kavita S.; Sulcova, Vladimira; Schwartz, Stuart; Noble, Julie E.; Phillips, Jeffrey; Brasel, Jo Anne; Huff, Kenneth; Lin, Henry J.

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 61 KB
• Volume: 92
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/(sici)1096-8628(20000501)92:1<69::aid-ajmg12>3.0.co;2-o

✦ Synopsis

We observed an analphoid marker chromosome stable through cell division in a 16year-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 ␣-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.