12 out of every 100 people carry the deafness gene, and eugenics are screened and monitored

图/IC photo

According to the World Health Organization, more than 1.5 billion people worldwide currently suffer from hearing loss, of which 430 million suffer from disabling hearing loss. It is estimated that by 2050, more than 700 million people may have disabling hearing loss. Globally, 34 million children suffer from deafness or hearing loss, and 60% of these cases are caused by preventable causes. How can I effectively prevent deafness or hearing loss?

Both spouses undergo genetic screening before trying to conceive

According to epidemiological surveys, one in every 1,000 newborns has congenital deafness. Congenital deafness is concomitant deafness at birth, 60% of congenital deafness is genetically recessive, and 40% of congenital deafness is due to factors during pregnancy and childbirth. "Gene recessive inheritance is that both parents are not deaf, but the child has congenital deafness, because both parents carry a deafness gene, and the individual gene does not occur on its own, but it will occur when combined." Gao Zhiqiang, director of the Department of Otorhinolaryngology of Peking Union Medical College Hospital, said that the carrying rate of deaf genes is very high, and 12 out of every 100 people carry genetic defects that can cause hereditary deafness.

Current deafness gene screening can already screen out most deafness genes. Gao Zhiqiang suggested that genetic screening of both husband and wife before trying to conceive, or screening of amniotic fluid during pregnancy, can help achieve eugenics. To prevent congenital deafness caused by factors during pregnancy and childbirth, the nursing care of the mother during pregnancy and childbirth should be strengthened, and the mother and newborn virus infections should be prevented.

Li Chengshan, a health care doctor in the children's group of Beijing Children's Hospital Shunyi Women's and Children's Hospital, introduced that during the fetal period, expectant mothers will be asked whether they need to check the deaf gene when doing Down's screening, this test is to detect whether the expectant mother is a carrier of the deaf gene, when the mother is a carrier, it is necessary to further test the father's gene, and if necessary, it is necessary to perform amniocentesis to know the condition of the fetus.

Prevent hearing loss and pay attention to newborn hearing screening

Genetic examination during pregnancy cannot fully determine the hearing problem of the fetus, and it is still necessary to pay close attention to the baby's hearing after childbirth, especially if the expectant mother has a viral infection during pregnancy. Newborn hearing screening is one of the most important ways to effectively prevent hearing loss, and screening can also prevent the use of harmful drugs in high-risk cases. Studies have shown that infants with mild to moderate hearing loss who can be diagnosed and treated before the age of 6 months are very beneficial to the development of language and social skills in infants and young children. The Beijing Municipal Health Commission stipulates that babies should undergo the first hearing screening 48 hours after birth, and collect the baby's deafness gene (heel blood) at 72 hours. Li Chengshan said that if the newborn's initial hearing screening does not pass, the hearing re-screening should be completed together at the 42-day re-examination, and if it is still not passed, a complete audiological assessment should be carried out at the corresponding diagnostic institution at the baby's age of about 3 months.

"The deafness gene is heel blood collected together with the newborn disease screening, but the results are not sent at the same time, and the deafness gene results are later than the newborn disease screening results, so many parents will ignore the results of the deafness gene." Li Chengshan reminded that when there is a problem with the deaf gene, it is necessary to consult and examine the corresponding hearing diagnosis institution. Up to now, the deafness gene examination is 9 sites of 4 genes with high incidence in China, and the problems that each gene and locus need to pay attention to in later life are not the same, such as some babies need to pay attention to the medication in the process of growth, and some babies need to avoid bumping. If the child is a carrier of the deaf gene, clinical counseling for the deaf gene can circumvent triggers that may cause hearing loss during growth, and these services can be provided by hospitals with hearing diagnosis qualifications.

Genetic testing may be done before the use of ototoxic drugs

The World Health Organization states that almost 60% of hearing loss in children can be prevented by immunization of rubella and meningitis. Hearing loss and deafness may occur as complications of other diseases such as measles, meningitis, rubella, and mumps. Efforts to prevent these diseases through vaccination and health programs can have a beneficial impact on the incidence of hearing loss and deafness. Rubella immunization of adolescent girls and women of childbearing age before pregnancy and prevention of CYTOV infection in pregnant women can reduce the risk of congenital hearing loss or deafness at birth.

Early management of otitis media (inflammatory disease of otitis media) is also effective in preventing deafness or hearing loss. Gao Zhiqiang said that generally mild otitis media does not cause deafness, but if measures are not taken in time, inflammation of the middle ear causes abnormal function and morphology of the ossicle chain, or violation of the inner ear may cause different degrees of deafness. Prevention of otitis media should pay attention to avoid mechanical damage caused by improper digging of the ear, prevent colds, prevent and actively deal with nasal and pharyngeal diseases, such as tonsillitis, sinusitis, proliferative adenitis, etc.

Noise control, safe hearing and ototoxic drug monitoring, and good ear hygiene can also help maintain good hearing and reduce the likelihood of hearing loss. The ototoxic side effects of drugs are very common, and there are nearly 100 known ototoxic drugs, of which most are deafness caused by aminoglycoside antibiotics. Common are streptomycin, gentamicin, kanamycin, amikacin, cisomicin, netimicin, tobramycin, noromycin, macroscopicin and so on. Gao Zhiqiang stressed that the improper use of these drugs should be avoided as much as possible in the clinic. "Not every patient who uses these drugs develops deafness. Drug-induced deafness is controlled by a gene called mitochondrial 12srRNA, and if this gene is abnormal, it is intolerant to ototoxic drugs and the risk of drug-induced deafness is very high. Therefore, if these ototoxic drugs must be used because of the disease, it is recommended to do drug-induced deafness gene testing to prevent the occurrence of the disease. ”

In addition, hearing examination is also one of the important ways to prevent hearing loss, do hearing examination frequently, find problems, intervene as soon as possible, and avoid causing more serious hearing loss.

Beijing News reporter Liu Xu proofread Lu Qian