Although there was no evidence that disruption of 8q24 in OS led to an elevated expression of RECQL4, there was a marked association between increased overall levels of S-CIN, determined by copy number transition frequency and higher levels of RECQL4.
The sensitivity of RTS cells to genotoxic agents exploiting cells with a known RECQL4 status is being elucidated and is aimed at optimizing the chemotherapeutic regimen for osteosarcoma.
It has been previously shown that RTS patients with RECQL4 mutations are at increased risk of osteosarcoma, but the precise incidence of cancer in RAPADILINO and BGS has not been determined.
Mutations in RECQL4 have been linked to three diseases including Rothmund-Thomson syndrome, which is characterized by osteoskeletal deformities, photosensitivity, and increased osteosarcoma susceptibility.
The skeletal malformations in RAPADILINO and RTS patients as well as the high osteosarcoma risk in RTS propose a special role for RECQL4 in bone development.
Analysis of the signalling relationships of these genes, as well as other expression markers of osteosarcoma, indicated that gene networks linked to RB1, TP53, PI3K, PTEN/Akt, myc and RECQL4 are associated with osteosarcoma.
Kaplan-Meier survival analysis was used to estimate the incidence of osteosarcoma among patients with and without mutations predicted to produce a truncated RECQL4 protein.
RECQL4 mutations cause several genetic disorders including Rothmund-Thomson syndrome (RTS), characterized by developmental defects and predisposition to osteosarcoma.
Mutations predicted to result in the loss of RECQL4 protein have been associated with osteosarcoma risk, but mutation(s)-phenotype correlations are better addressed by combined DNA and RNA analyses.