MINAR2 gene mutations trigger progressive listening to loss

Researchers on the John T. Macdonald Division of Human Genetics and the John P. Hussman Institute for Human Genomics on the College of Miami Miller Faculty of Medication have discovered that inherited mutations within the MINAR2 gene prompted deafness in 4 households. The gene variation principally impacts the inside ear hair cells, that are crucial to listening to.

MINAR2 gene mutations cause progressive hearing loss
Mustafa Tekin, M.D., professor within the Dr. John T. Macdonald Basis Division of Human Genetics and senior writer on the paper. Picture Credit score: College of Miami Miller Faculty of Medication

The authors consider the progressive nature of this listening to loss, in some affected people and in mice, may provide alternatives for therapy. The examine, titled “Mutations in MINAR2 encoding membrane integral NOTCH2-associated receptor 2 trigger deafness in people and mice,” was printed on-line June 21 within the journal PNAS (Proceedings of the Nationwide Academy of Sciences).

“MINAR2 performs a serious position in listening to, and these inherited mutations result in sensorineural deafness,” mentioned Mustafa Tekin, M.D., a professor within the Dr. John T. Macdonald Basis Division of Human Genetics and senior writer on the paper. “The findings recommend these instances could also be appropriate for intervention with genetic therapies.”

Dr. Tekin has been finding out the genetic underpinnings behind listening to loss for greater than 20 years, and has amassed a biorepository with genomic sequencing database of deafness-associated gene mutations in households all around the world.

“We first take a look at recognized gene mutations,” mentioned Dr. Tekin, who can be chief of the Division of Medical and Translational Genetics, director of the Biochemical and Molecular Genetics Diagnostic Laboratory, and a professor of otolaryngology. “If we don’t discover any, we conduct entire genome sequencing to doubtlessly establish new genes or one thing we might have missed within the preliminary take a look at.”

DNA variants discovered

On this examine, the staff sequenced a Turkish household’s genome, concentrating on recognized deafness genes, however discovered nothing. Following up with entire genome sequencing, they discovered DNA variants in MINAR2, which had solely just lately been described within the analysis literature. Scientists are nonetheless filling within the blanks on the gene’s perform.

Having recognized the variations in MINAR2 in a single household, Dr. Tekin’s staff searched their database and located a second household with a special mutation in the identical gene. Additional investigation confirmed their findings in animal research and recognized three totally different MINAR2 mutations, which prompted deafness in 13 individuals from 4 households.

We discovered this gene serves an necessary perform. The protein localizes in hair cells and different areas which might be crucial to listening to. Future analysis will deal with clarifying the gene’s position.”

Mustafa Tekin, M.D., Professor, Division of Human Genetics, Dr. John T. Macdonald Basis

Potential for intervention

Hair cells convert sound into electrical alerts, that are then despatched to the mind. Usually, when youngsters are born deaf, they’ve few, if any, dwelling hair cells. Because of this, gene therapies and different regenerative efforts would doubtless fail. Nevertheless, within the mouse knockout mannequin of MINAR2, hair cells stay alive till a later age. This gradual lack of listening to may enable for therapy.

“What’s stunning and promising for potential intervention is that, once we regarded on the hair cells in our mouse mannequin, they’re alive till a sure age,” mentioned Tekin. “That offers us a window of alternative to offer therapy. We may insert the traditional gene and doubtlessly restore listening to.”

Journal reference:

Bademci, G., et al. (2022) Mutations in MINAR2 encoding membrane integral NOTCH2-associated receptor 2 trigger deafness in people and mice. PNAS. doi.org/10.1073/pnas.2204084119.



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