1. “Why is my child deaf when we are all normal?” Recessive inheritance (similar to thalassemia). 2. “Why does a single dose of medication lead to lifelong deafness?” Carrying a drug susceptibility gene. 3. “Why does the child’s hearing drop sharply after a fall or cold?” Large vestibular aqueduct syndrome. 4. What is the use of the test? For adults: guidance on medication, guidance on fertility. For children: guidance on treatment and medication, guidance on life. 5. How likely is it that a child with a “positive” test will be deaf? Different cases are treated differently. GJB2, SLC26A4; mitochondrial gene. 6.Should the child be tested if the parents have been tested? It is recommended that children of “normal” people should also be screened for mutations.