Young Children Congenital Causes
The term congenital hearing loss implies that the hearing loss is present at birth. It can include hereditary hearing loss or hearing loss due to other factors present either in utero (prenatal) or at the time of birth. Genetic factors are thought to cause more than 50% of all incidents of congenital hearing loss in children.
Genetic hearing loss may be :- 1. Autosomal dominant
2. Autosomal recessive
3. X-linked (sex chromosome)
In autosomal dominant hearing loss, one parent who carries the dominant gene for hearing loss and typically has a hearing loss passes it on to the child. In this case there is at least a 50% probability that the child will also have a hearing loss. The probability is higher if both parents have the dominant gene (and typically both have a hearing loss) or if both grandparents on one side of the family have hearing loss due to genetic causes. Because at least one parent usually has a hearing loss, there is prior expectation that the child may have a hearing loss.
In autosomal recessive hearing loss, both parents who typically have normal hearing, carry a recessive gene. In this case the probability of the child having a hearing loss is 25%. Because both parents usually have normal hearing, and because no other family members have hearing loss, there is no prior expectation that the child may have a hearing loss.
If your child does not exhibit the average behavior for his/her age, get professional advice from your Audiologist, your hospital, or a local speech and hearing clinic. Now days, the facilities for testing the hearing of a newborn child are available at most of the hospitals and Audiologist clinics. As all of the hearing tests are non-invasive and there no side effect of these tests, there’s no reason, why one should delay in getting his child’s hearing tested. If no hearing loss exists, the test would not have caused any harm to your child. However, if there is a hearing problem, early detection of hearing loss and going through the appropriate remedies, whether in the form of medicine, surgery or fitting of hearing aids at an early age is going to decide your child’s future in term of education, communication and career. Remember, early diagnosis of a hearing loss in your child ensures that you can begin an immediate fitting of hearing aids and an early start in an educational program for children with hearing impairments.
In X-linked hearing loss, the mother carries the recessive trait for hearing loss on the sex chromosome and passes it on to males, but not to females. There are some genetic syndromes, in which, hearing loss is one of the known characteristics. Some examples are:-
1.Down syndrome (abnormality on a gene)
2. Usher syndrome (autosomal recessive)
3. Treacher Collins syndrome (autosomal dominant)
4. Fetal alcohol syndrome (genetic abnormality)
5. Crouzon syndrome (autosomal dominant) * Alport syndrome (X-linked).
Other causes of congenital hearing loss that are not hereditary in nature include:-
1. prenatal infections
2. illnesses, or conditions occuring at the time of birth or shortly thereafter.
These conditions typically cause sensorineural hearing loss ranging from mild to profound in degree. Examples include:-
1. Intrauterine infections including rubella (German measles),
2. cytomegalovirus, and * herpes simplex virus
Complications associated with the Rh factor in the blood:-
3.Toxemia during pregnancy
4.Lack of oxygen (anoxia) Acquired Causes
Acquired hearing loss is a hearing loss which appears after birth, at any time in one’s life, perhaps as a result of a disease, a condition, or an injury. The following are examples of conditions that can cause acquired hearing loss in children are:
1.Ear infections (otitis media) (link to specific section above)
2. Ototoxic (damaging to the auditory system) drugs
6. Chicken pox
9. Head injury
10. Noise exposure
11. APGAR scores of below 4 at one minute and below 6 at five minutes (newborn vital signs measured at birth).
12. Low birth weight below 3.5 lbs.
13. Admission to Newborn Intensive Care for more than five days.
14. Jaundice at birth requiring exchange transfusion.
15. SUSPICION THAT YOUR CHILD MAY NOT BE HEARING WELL (Doesn’t startle to loud sounds or respond to your voice, speech delay present).
16. Visible malformations of the head, neck or ears.
17. Family history of permanent or progressive hearing loss in childhood. 18. Malformations of middle and/or inner ear structures.