Benign but locally aggressive tumor.

Occurs mainly in vertebrae and flat bones. Multiple involvement is frequent.

May involve the arrest of maturation of the osteoblasts caused by USP6 overexpression and dysregulation of autocrine BMP (bone morphology protein) signaling (Lau et al., 2010).

Usually seen in patients aged 10-20 years; represents about 5% of primary bone tumours; slightly more frequent in female patients.

Forms a spongy hemorrhagic mass; symptoms are pain, swelling, pathological fractures. One case to date was found with a t(3;17)(q21;p13), a 7-year-old girl with a tumor located in the tibia (Oliveira et al., 2005).

Surgical curetage.

Recurrence occurs in one fourth of cases.

The t(3;17)(q21;p13) was the sole anomaly.

CNBP (CCHC-type zinc finger nucleic acid binding protein)

3q21.3

CNBP, also called ZNF9, is made of 7 CCHC-type Zn fingers. Nucleic acid binding protein; binds single stranded DNA and RNA; act as a regulator of transcription and translation of many genes, including MYC. CNBP may regulate gene expression by catalyzing the formation of G4s (G-quadruplexes, formed by intramolecular four-stranded DNA structures).

Myotonic dystrophy DM2 is caused by expansion of a (CCTG)(n) in CNBP. CNBP has also been implicated in sporadic inclusion body myositis (review in Calcaterra et al., 2010).

USP6 (ubiquitin specific protease 6 (Tre-2 oncogene))

17p13.2

USP6, also called TRE17/ubiquitin-specific protease 6 (USP6), is a deubiquitinase. It is the first de-ubiquitinating enzyme to activate NF-KB, and requires both catalytic subunits of IKK (IKKalpha and IKKbeta) (Pringle et al., 2011).

5 CNBP - 3 USP6

Fusion of the noncoding exon 1 of CNBP to USP exon 2 (i.e. to the entire coding sequence of USP6, resulting in upregulation of USP6).