We performed an in-depth clinical analysis of a phenotype not previously observed in sSRC(6) patients and discuss the potential influence of genes located within this region on the skeletal presentation observed.Ī small supernumerary marker chromosome (sSMC) is a rare chromosomal abnormality characterized by presence of cytogenetic content in addition to the normal 46 chromosome karyotype.

Patient 2 was mosaic for a sSRC that encompassed a 26.8 Mb gain from 6p21.2 to 6q12. Cytogenetic analysis further revealed a complex patient of mosaicism with some cell lines displaying either one or two copies of the marker indicative of both tetrasomy and hexasomy of this region. In patient 1, array comparative genomic hybridization (CGH) detected a tandem duplication of region 6p12.3 to 6q12 per marker chromosome. Lesion pathology in both patients demonstrated a bland cyst wall with woven dysplastic appearing bone entrapped within it. Imaging revealed decreased bone mineral density, mutiple multiloculated cysts and cortical thinning. Both patients presented with a complex bone disorder characterized by severe osteopenia, pathologic fractures and cyst-like lesions within the bone. We describe two unrelated patients with small SRCs derived from chromosome 6 with a novel bone phenotype.

The spectrum of this disorder can range from phenotypically normal to severe developmental delay and congenital anomalies. Small supernumerary ring chromosome 6 (sSRC(6)) is a rare chromosomal abnormality characterized by a broad clinical phenotype.

Chromosome 6 novel