Lindsey Williams was happy and excited to be a mother. Her first pregnancy was normal, and she gave birth to a baby girl in 2015. At birth, newborns are given a variety of tests and screenings to check for any health issues. Lindsey’s daughter did not pass the newborn hearing screenings.

Through follow-up testing, it was determined that Lindsey’s daughter had bilateral sensorineural hearing loss. This type of newborn hearing impairment is not uncommon. At the time, they did not seek additional testing. As Lindsey’s daughter grew, the family found doctors and resources to help them navigate her hearing impairment journey.

When Lindsey’s daughter was 3-years-old, Lindsey was told that her daughter was a candidate for cochlear implants. A cochlear implant is a small electronic device that electrically stimulates the cochlear nerve (nerve for hearing). A cochlear implant may help someone with hearing impairment restore or improve the ability to hear and understand speech.

Lindsey’s daughter had mild sloping hearing loss, or the loss is mild for lower frequencies but profound for higher frequencies. After this diagnosis, Lindsey was hopeful that they could preserve her daughter’s low-frequency hearing. A physician also told Lindsey that her daughter had probably contracted cytomegalovirus (CMV) infection at birth which likely caused her to be hard of hearing.

“I was at a loss trying to retrace my steps and understand if her hearing loss was connected to the pregnancy in any way,” shared Lindsey. “I blamed myself and thought that maybe something I did before or during pregnancy had caused her hearing loss.” 

Lindsey’s years of worry and uncertainty about the cause of her daughter’s hearing impairment were about to come to an end.

Growing family

In 2017, Lindsey learned that she was pregnant again. During the pregnancy, Lindsey worried about her baby’s health. Lindsey’s son was born in January 2018. He also did not pass the newborn hearing screening, but his Auditory Brainstem Response (ABR) evaluation was normal. The ABR evaluation is a follow-up test for newborns to determine if the ear and brain pathways are functioning. 

As Lindsey’s son grew, his speech and language development were normal. Everyone around him believed that his development was exceeding expectations. 

“Everyone who interacted with my son thought that his development was in a normal range,” said Lindsey. “Often we felt like his speech and language was above average for his age.”

Identifying clues

Since Lindsey’s daughter was hard of hearing, she began receiving services through Alabama Children’s Rehabilitative Services (CRS). Through the program, both of the children were monitored regularly for any changes in development and in particular hearing changes.

Due to the coronavirus pandemic, Lindsey’s son was not tested for a year and a half. They did not notice any changes in his behavior or hearing, so they did not have concerns about his development. When they finally had an opportunity to get tested in January 2021, it took three tries to get a good audiogram.

The audiogram showed that he had significant sloped hearing loss as well. Neither Lindsey nor her husband had any idea. They felt that they had been trained to know what to look for, but they didn’t see it. Since their daughter’s deafness was possibly attributed to a virus rather than a genetic cause, they had no reason to expect it would happen again. The doctors and nurses said that the hearing loss was probably a recent development which explained why his speech and language had developed so well to this point. Since Lindsey’s son had grown up in a listening and spoken language household, it was likely that his deafness was hidden.

Both of the children’s audiograms were similar around the age of three. With two similar cases, Lindsey’s worry of a CMV infection was put to rest. When their daughter was first diagnosed, the Williams didn’t consider genetic testing for many reasons, including lack of understanding and information, cost, and no doctor recommendation to get the testing. But now they suspected that the cause was not due to a virus. 

Smith Family Clinic visit

Through the family’s participation with CRS, the Williams learned about a partnership with the Smith Family Clinic for Genomic Medicine on the HudsonAlpha Institute for Biotechnology campus. Through this partnership, CRS hosts a genetics clinic once a month for patients to access consultations and genetic testing. With two children now diagnosed with hearing impairment, the Williams family was a good candidate.

The Williams family visited the Smith Family Clinic in Huntsville and met with a genetics physician and a genetic counselor who explained the tests they planned to run to get an answer. 

“Everyone at the clinic was so nice and welcoming,” said Lindsey. “The treatment was very personalized and the small clinic made us feel at ease. The doctor spent a lot of time interacting with the children to make them feel comfortable.”

The clinicians were able to take a cheek swab or saliva sample from both of the children for the genetic testing. 

Diagnosis day

After waiting for the test results, the family was asked to visit the clinic again to hear the results. The Williams family was taken to the Jan Smith Training and Conference Room and met with a medical geneticist and genetic counselor. They learned that both children had variants in the CLDN14 gene. 

“We all hit the lottery with genes,” laughed Lindsey. “They told us that it was likely that both parents had recessive genes for the CLDN14 variation. There was a one in four chance that each kid would have it. So, for both children to have it, is really rare.”

The Smith Family Clinic team was able to share further information and articles about the gene variation with the family.

“We were very concerned about preserving our daughter’s low-frequency hearing during cochlear implantation, but we had been advised not to worry about that because she would likely lose all of her hearing due to CMV anyway,” said Lindsey. “The studies the genetic counselors shared with us when going over our test results showed that it’s typical for people with the CLDN14 variants to have progressive hearing loss more in the high frequencies and for the low-frequency hearing to be relatively stable. Many of the audiograms in the studies were eerily similar to those of our children. So, that low-frequency hearing was worth preserving, and thankfully, our surgeon was able to preserve it. We will be sharing this genetic information when it’s time to talk about cochlear implants for our son, and we will hope for the same outcome.”

With this newfound genetic diagnosis, the Williams family is equipped with information to help their children. Now that they know that their children’s deafness is genetic, they are able to stay vigilant on their medical journey, especially with their son as they continue to monitor his progression. In addition, when they are ready, they will be able to share this information with their children and impact future family planning.

To learn more about genetic testing at the Smith Family Clinic, visit smithfamilyclinic.org.