A study carried out in mice at the University of Manchester — in collaboration with Murdoch Children’s Research Institute, Australia, and the Institute of Genetic Medicine, Newcastle University — has led researchers to believe the drug carbamazepine, used commonly to treat epilepsy and bi-polar disorder, could also be useful in promoting bone growth for people with metaphyseal chondrodysplasia type Schmid (MCDS) (commonly referred to as ‘dwarfism’).
This disorder causes skeletal dysplasia, which impedes bone growth and leads to disproportionately short limbs. Administering mice with carbamazepine was shown to mitigate the effects of the MCDS, leading to a potential treatment for people with dwarfism.
Human trials are said to be taking place at the end of the year.
University of Manchester biochemist Professor Ray Boot-Handford who led the study, said: “The indication from this study is that carbamazepine might work in a number of other conditions, where the same process involving mutant protein accumulation takes place.
“But clearly, the next stage is to test it in humans.”
Another researcher, Professor Michael Briggs, from Newcastle University said: “It exemplifies the power of drug re-purposing for rare diseases: there has been no involvement of big pharma and this inexpensive drug has had a great safety record since the 1950s.”
MCDS is caused by a mutation in ‘collagen X’, a protein responsible for cell differentiation and bone growth. It is believed that the introduction of carbamazepine degrades the mutant form of collagen X, allowing the cells to differentiate and grow properly.
In the mice studied, three weeks of drug administration showed a marked reduction of hip dysplasia and misallignment. The results are published in The Journal of Clinical Investigation.
This is not the first time that drugs used for one disorder have been found to treat or cure other, seemingly unrelated disorders; Sildenafil (or ‘Viagra’) was originally developed as a drug to treat pulmonary hypertension, but was also accidentally found to treat erectile dysfunction.