New Genetic Discovery Reveals Stable Form of Childhood Hearing Loss

Researchers in Italy have identified a new genetic variant that causes stable, non-degenerative hearing loss, according to a study published in The Journal of Applied Laboratory Medicine (Jalm). The discovery, made at the Ospedale dell’Angelo in Mestre, involves a specific combination of variants in the TRIOBP gene that prevents the progression to profound deafness.

The case began when a child with bilateral sensorineural hearing loss was treated by Prof. Rosamaria Santarelli at the Centro audiologico d’eccellenza of the Civile Hospital of Venice. After a decade of clinical observation, Santarelli suspected a genetic origin for the adolescent’s hearing impairment.

The patient’s genetic material, along with that of close family members, was analyzed at the Laboratorio di Genetica e citogenetica of the Ospedale dell’Angelo. Led by primary physician Mosè Favarato, the team sequenced 115 genes associated with auditory perception.

How does the new TRIOBP genetic variant affect hearing?

The new variant allows for the synthesis of at least one functional protein necessary for hearing, according to Prof. Mosè Favarato. Previous literature only described TRIOBP anomalies that completely destroyed these proteins, leading to severe deafness that worsened over time.

This specific combination of variants preserves residual hearing capacity. Favarato stated this explains why the patient’s condition remained stable over the last ten years and suggests the hearing loss will not progress to profound deafness.

Why is genetic testing critical for childhood hearing loss?

Many genetic forms of childhood hearing loss are transmitted via autosomal recessive patterns, Santarelli explained. This means parents are often healthy carriers with no hearing loss themselves, making the condition appear isolated in the child.

Because hearing loss does not always appear at birth, Santarelli emphasized that genetic investigation is indispensable for all cases of isolated childhood hearing loss. The Venice center has recently referred over 200 patients and their families to the Mestre laboratory for such testing.

What are the long-term implications for patients?

The discovery enables primary prevention for the patient’s future children through genetic counseling and family planning, according to Chiara Bovo, head of the health directorate of Ulss 3 Serenissima.

Bovo also stated that this case study serves as an initial step toward the development of future gene therapies. The study was co-authored by geneticists Dario Degiorgio, Elena Greco, Marianna Beggio, Edoardo Peroni, and Giulia Favretto, alongside otoneurologists Erennio Natale, Cristina Gondiu, Elona Cama, and Pietro Scimemi.

Alberto Stefani, President of the Veneto Region, stated that such research defines the prospects for therapy and clinical practices used globally.

Frequently Asked Questions

Which gene was identified as the cause of this stable hearing loss?
The study identified a new combination of variants in the TRIOBP gene.

How does this discovery differ from previous medical literature?
Previous records associated TRIOBP mutations with severe deafness that progressed to profound loss; this new variant results in stable, non-degenerative hearing loss.

Can parents be unaffected even if their child has genetic hearing loss?
Yes. According to Prof. Santarelli, most childhood genetic hearing loss is autosomal recessive, meaning parents are often healthy carriers.

Do you believe genetic screening should be standard for all children exhibiting early hearing loss?