Newborn genetic screening for hearing impairment: a population-based longitudinal study

Area of Science:

• Genetics
• Audiology
• Neonatal screening

Background:

• Genetic mutations are a significant cause of congenital deafness.
• Newborn hearing screening identifies some, but not all, infants with hearing loss.
• Genetic screening offers a potential method to identify infants at risk for hearing impairment.

Purpose of the Study:

• To evaluate the long-term outcomes of newborns who screened positive for deafness-causing mutations.
• To assess the cost-effectiveness of population-wide genetic screening for deafness.

Main Methods:

• Simultaneous hearing and genetic screening for four common deafness mutations in 5173 newborns.
• Analysis of serial audiometric results up to age 6 in children with confirmed genotypes.
• Targeted mutations included GJB2 (p.V37I, c.235delC), SLC26A4 (c.919-2A>G), and mitochondrial m.1555A>G.

Main Results:

• 1.6% of newborns had conclusive genotypes for deafness mutations (GJB2 p.V37I/p.V37I, GJB2 p.V37I/c.235delC, m.1555A>G).
• 56.1% of these infants passed initial newborn hearing screening.
• Progressive hearing loss, deteriorating by ~1 dBHL/year, was observed in children with GJB2 p.V37I/p.V37I and p.V37I/c.235delC genotypes.

Conclusions:

• The study delineated longitudinal auditory features of the GJB2 p.V37I mutation in a general population.
• Newborn genetic screening is valuable for identifying infants with late-onset or progressive hearing loss.
• This approach can detect hearing impairments missed by standard newborn hearing screening.