What causes congenital deafness?
Possible but not commonly seen.
I had gone through your question and understand your concerns that your parents-in-law are having deafness.
Congenital deafness could be genetic, non genetic (syndrome) or due to infections. Some syndromes can show in future generations.
It can be diagnosed by detailed history, detailed ent examination, genetic tests and special tests (audiometry).
Sense of hearing is very important in developing speech and vocabulary. In syndromes, where inner ear mechanisms are absent, restoring hearing is a difficult task.
I suggest you to consult ENT surgeon, get detailed examination of your parents-in-law to know the cause.
Hope this answers your question, if you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions.
Wishing you good health.
Molecular genetic testing.
Thanks for considering my answer and for your follow up.
It is determined that you and your partner carry the silent (recessive) gene which causes a hearing loss, then each of the children resulting with that partner have a 2 in 3 (66%) chance of also carrying that same gene.
There are many genes that are involved in hearing. Sometimes, a gene does not form in the expected manner. This is called a mutation. Some mutations run in families- more than one person (familial, runs in families), If only one person in the family has hearing loss-(sporadic). That is, it does not run in the family.
About 70% of all mutations causing hearing loss are non-syndromic. This means that the person does not have any other symptoms. About 30% are syndromic- person has other symptoms besides hearing loss. For example, some people with hearing loss are also blind.
Kindly discuss with gynecologist/ent surgeon about screening audiometry, blood tests and genetic testing.
Molecular genetic testing - Testing that involves the analysis of DNA, either through linkage analysis, sequencing, or one of several methods of mutation detection.
Hope, I have answered your query.