Wednesday, September 16, 2009

Tuesday, September 15, 2009

More Pictures of Kiliana

About Connexin 26

  • The most common cause of hearing loss in American and European populations is a mutation in the connexin 26 (Cx26) gene.

  • Cx26 has a carrier rate of 3%, similar to that for cystic fibrosis, and it causes about 20% of childhood deafness.

  • Everyone has two copies of this gene, but if each birth parent has a flawed copy of the GJB2/Connexin 26 gene, the baby may be born with a hearing loss. The hearing loss occurs because the mutation is suspected of disrupting potassium flow in the inner ear.
  • Connexin 26 mutations occur primarily in Caucasians, Ashkenazi Jews, and some Asian people.
  • Carriers who only have one copy of the gene (i.e. one normal gene and one mutated gene) do not manifest any of the signs of the condition, but have a 1 in 2 chance of passing on the defective gene to their children (who would then also be carriers only), and a 1 in 4 chance of having an affected child if the other parent is also a carrier.
  • Recent medical evidence has shown that there is an additional complexity to Connexin 26 mutations. Currently, only about 75% of the mutations predicted to be Cx26 actually show up in genetic testing. In some cases this may be due to mutations in another gene immediately adjacent to Cx26 called Connexin 30 (Cx30) at gene (GJB6). Connexin 26 and Connexin 30 are expressed in the same hair cells of the cochlea. Cx26 and Cx30 are similar, sharing over three-quarters of the same amino acid sequences. These considerations have led researchers to believe that mutations in Cx30 are probably also responsible for hearing loss.
  • The GJB2 gene contains the instructions for manufacturing a number of proteins, including Connexin 26. Connexin proteins in general are called “gap-junction proteins” which are necessary for cells to communicate with each other. Without sufficient levels of Connexin 26, the potassium flow from hair cells in the cochlea is disrupted, resulting in extremely high levels of potassium in the Corti s organ, leading to the profound sensorineural hearing loss.

Monday, September 14, 2009

Pictures of Kiliana Elyse

About Sweet Kiliana Elyse

My daughter, Kiliana Elyse, was born on August 17th, 2008. Everything seemed normal - she was developing wonderfully in every area, even saying "ma", "da", and "un-gee" (for hungry) by the age of 5 months. Then around 6 months of age, she stopped. Stopped talking, stopped responding to sounds.

We took her to get her hearing checked and her pediatrician sent us to Nationwide Children's Hospital to get her an ABR test. She failed and was diagnoses with profound bilateral sensorineural deafness. Genetic testing was done and the results were that she is a carrier of a recessive gene called Connexin 26, which causes deafness.

Kiliana was fitted with hearing aids on August 24th, 2009. They seem to do no good with aiding her to hear. On September 11th, her hearing aids were maxed out. She seemed to be able to hear a little, but not enough to acquire normal speech. Her doctor started the Cochlear Implant candidacy process, and, hopefully, she will be implanted late-November, early-December.