Causes of Congenital Hearing Loss

I have been curious for a long time as to what the common causes of hearing loss are. There are lots of places that state the known causes, but nowhere (until now!) was it possible to see how common the causes were. Without further ado, here is our estimate (see below for disclaimers!) of how common common causes of congenital (at birth) hearing loss are:

GeneticUnknown non-syndromatic with recessive behavior16.4%
GeneticConnexin 26 (GJB2)16.4%
Birth RelatedOther birth/pregnancy related causes16.3%
Birth RelatedCMV (cytomegalovirus)12.5%
GeneticUnknown non-syndromatic with dominant behavior8.4%
GeneticDown Syndrome5.5%
Birth RelatedHypoxia/Anoxia (lack of oxygen)4.3%
GeneticPendred Syndrome2.8%
Birth RelatedHyperbilirubinemia (jaundice)2.5%
GeneticWaardenburg Syndrome2.5%
GeneticCHARGE Syndrome2.5%
Birth RelatedMaternal Alcohol/Drug Usage2.0%
GeneticUsher Syndrome1.3%
Birth RelatedBacterial Meningitis1.25%
GeneticTreacher Collins Syndrome1.0%
GeneticNon-Syndromatic - X-Linked/Mitochondrial0.8%
GeneticBranchio-Oto-Renal Syndrome0.6%
GeneticStickler Syndrome0.6%
GeneticGoldenhar Syndrome0.5%
GeneticOther Syndromes0.5%
Birth RelatedToxoplasmosis0.5%
Birth RelatedHerpes Simplex0.5%
Birth RelatedSyphilis0.15%
GeneticCrouzon Syndrome0.1%
GeneticJervell & Lange Syndrome0.1%
Birth RelatedRubella0.0%
Birth RelatedToxemia (pre-eclampsia)0.0%
Birth RelatedMaternal Diabetes0.0%

Now, the disclaimers I'm sure you've been waiting for! The goal of this chart is to show known causes of hearing loss at or shortly after birth (within about a month), in the United States, as of the end of the year 2007. Geography is important; for example, rubella is almost non-existant in newborns in the United States, but common in other countries, and genetic mutations are sometimes more common in certain geogrpahical areas. The year is important, too, as factors change over (for example, as the percentage of hearing loss caused by rubella goes down, the percentage for all other factors combined has to go up).

Determining the percentages is much more of an art than a science. This is because lots of information isn't known. Information is updated frequently; some data is 10-20 years old. Some data is based on very small samples of people. Some refer to "hearing loss", while others refer to "deafness". For most syndromes, there isn't much information about what percentage of affected people have hearing loss, and what percentage of them had hearing loss since birth. For more issues like this, and the rationale behind the numbers, see our boring Etiology Rationale page.

The information comes from many, many sources. The original data was all in different forms, the few that did state the percentage of congenital hearing loss did so with imprecise numbers. By far the biggest source of data was the Regional and National Summary Report of Data from the 2004-2005 Annual Survey of Deaf and Hard of Hearing Children and Youth by the Gallaudet Research Institute (December, 2005). Please note that that data was not used as a starting point (see our Etiology Rationale for more details).

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