Progress Update: SLC34A2 as a Biomarker for FSHD

Progress update by Dr. Robert Bloch
See grant SLC34A2 as a Biomarker for FSHD

We previously showed that one of the proteins that appear as a result of the DUX4 program in FSHD is the sodium, phosphate cotransporter protein, SLC34A2, can be detected in human FSHD muscle biopsies but not in control muscle. We found a similar difference between human muscles that we grow in mice from muscle cells obtained from healthy individuals or from FSHD patients. In this grant, we proposed to learn how unique the SLC34A2 protein is in these respects and to determine if SLC34A2 could be found at significantly higher levels in the serum of FSHD patients than in control human serum.

Although we lost a considerable amount of time and money due to the pandemic, we’ve recently made good progress. In particular, we have confirmed that SLC34A2 is one of only 1 or 2 proteins, of 20 or so that we have examined so far, that we find to be present at higher levels in FSHD biopsy samples than in healthy samples. We also find that it is present at significantly higher levels in the serum of FSHD patients than in control human serum.

Our results suggest that SLC34A2 may be a useful serum protein biomarker for FSHD – the first identified to date. We are now testing the possibility that changes in the levels of SLC34A2 in the sera of mice treated with experimental therapies for FSHD will decrease as the DUX4 program is suppressed.