Hearing Loss, about 2 / 3 can be attributed to genetic mutations, is the most common congenital defects, so genetic testing has become a powerful tool for the clinical assessment.
Around 75–80% of all cases are inherited by recessive genes, 20–25% is inherited by dominant genes, 1–2% is inherited by X-linked patterns, and less than 1% is inherited by mitochondrial inheritance.
There are two different forms: “Non-Syndromic” (means hearing impairment and nothing else) and “Syndromic” (means hearing impairment with other clinical findings). By far, the more common is Non-syndromic hearing loss which includes 2/3 of all genetic hearing losses.
Hearing Loss have a significant impact on the future of the baby
Language learning and listening development are inseparable. Some children delayed language development is caused because of hearing impairment. If can grasp the gold correction period of six months, it is a great help to the baby for language learning.
‧ Since one of the ways babies learn is through hearing and studies show that children identified with hearing impairment prior to 6 months of age have a better chance of developing skills, all newborns are recommended.
Especially for those:
1. Who has a family history
2. Who was exposed to drugs known to affect hearing
3. Who has low birth weight and/or prematurity, or oxygen deprivation or breathing difficulties at birth.
4. Who has high bilirubin levels (yellow color)
5. Who has abnormal head or face structures
6. Who has infections such as cytomegalovirus, syphilis, herpes, or toxoplasmosis.
7. Who has low Apgar scores (which assess several health factors at one and again at five minutes after birth)
Through continuous research and development, we establish an accurate and stable newborn genetic testing. We use newborn bloodspot screening, a small sample of blood taken from the baby’s heel, to do DNA extraction for screening hearing impairment gene.
The newborn genetic targeted 6 deafness-associated mutations commonly found in Taiwanese population, including c.109G>A and c.235delC of the GJB2 gene, c.919-2A>G and c.2168A>G of the SLC26A4 gene, mitochondrial m.155A>G of the 12S rRNA gene and c.5098G>C of the OTOF gene.
Compare to two traditional methods, Automated Auditory Brainstem Response (AABR) measures how the hearing nerve responds to sound and Otoacoustic Emissions (OAE) measures sound waves produced in the inner ear, genetic testing is suggested to identify the causes of hearing impairment. Since the traditional hearing loss screenings CAN NOT identify mild, moderate hearing impairment and progressive type which results in the hearing getting worse with age, the early detection through “Hereditary hearing loss screening” is very important.
Step1：Discuss with your doctor and fill the consent form as well.
Step2：Take a few drops of blood from your baby’s heel after your baby is 24 hours old, but before your baby leaves the hospital.
Step3：The blood sample is sent to a newborn screening laboratory.
Step4：DNA will be extracted from the blood for screening.
Step5：The report will be given in 14 working days.
Note: National Institutes of Health, the American Academy of Otolaryngology/Head and Neck Surgery, and the American Academy of Pediatrics have recommended that hearing impairment in infants be identified.