A new skeletal disease is on the examination table
Researchers have published findings on a new skeletal disease and how it is caused. The disease, a kind of skeletal dysplasia, was first observed in a child and parent from a Swedish family, they said in the publication in the journal Nature Medicine. “They came to my clinic,” says the study’s lead author Giedre Grigelioniene, […]
A new skeletal disease is on the examination table
Researchers have published findings on a new skeletal disease and how it is caused.
The disease, a kind of skeletal dysplasia, was first observed in a child and parent from a Swedish family, they said in the publication in the journal Nature Medicine.
“They came to my clinic,” says the study’s lead author Giedre Grigelioniene, physician and associate professor at the Department of Molecular Medicine and Surgery, Karolinska Institutet.
“They’d received a different diagnosis previously, but it didn’t fit with what we were seeing in the X-rays. I was convinced that we were looking at a new diagnosis that had not been described before.”
It is congenital. Small RNA molecules (one of four macromolecules essential for all forms of life) play a role but that role has never before been observed in a congenital human disease.
Skeletal dysplasia is an umbrella term for more than 100 conditions that can affect normal growth of bones and cartilages. Some simply call it dwarfism.
The results from the study are important for affected patients but can also help scientists to understand other rare diagnoses.
The disease comes from mutation in a gene called MIR140. The gene doesn’t give rise to a protein but to a “micro-RNA (miR-140), a small RNA molecules that regulates other genes, Grigelioniene found, together with Fulya Taylan, assistant professor at the same department at Karolinska Institutet.
“This causes a change in skeletal growth, deformed joints and the delayed maturation of cartilage cells in the patients, who have short stature, small hands and feet and joint pain,” says Dr Grigelioniene.
The identified mutation knocks out a normal function of the micro-RNA, which is replaced by a different function.
The mechanism is called neomorphic and has never before been described involving small RNAs in human congenital disease.
A similar mechanism in cancer cells was described last year in a paper in Nature Genetics by researchers who were also involved in the present study.
According to Dr Grigelioniene, the results now published are important both for patients with the disease and for scientists interested in how small regulatory RNA molecules are involved in the development of human congenital disease.
“We plan to examine whether similar mechanisms with mutations in small RNA genes are involved in the development of other rare congenital disorders,” she says.
“As for patients who already have this disease, the results mean that they can choose to use prenatal foetal diagnostic, in order not to pass the disease on to their children.”