What Is Hereditary Deafness?

Some of these patients do not respond to sound after birth. If they do not wear hearing aids and receive language training, they will not be able to communicate normally, but they will also hinder the normal intellectual development of deaf children and become a heavy burden on the family and society. Some patients only develop symptoms between the ages of 10 and 30 years. They show hearing loss, which increases with age, and eventually reaches severe deafness. Although these patients have learned to speak, they can't perform normal with others due to hearing impairment. I ca nt watch movies, TV, listen to radio, and music like normal people, which is a great pain for myself and my family.

Hereditary deafness

Hereditary hearing loss refers to deafness caused by genetic and chromosomal abnormalities. This disease is deafness caused by changes in parents' genetic material (including chromosomes and the genes located in them) that are passed on to offspring, and it occurs in a certain amount in grandchildren. One in every 1,000 newborns has congenital deafness, and more than 60% of it is caused by genetic factors. The incidence of hereditary deafness has exceeded 27/1000. Among all deaf patients, hereditary deafness is about 50%. Hereditary deafness is divided into two categories: syndrome hereditary deafness and non-syndrome hereditary deafness. The former means that in addition to deafness, there are also lesions in the eyes, bones, kidneys, skin and other parts. This type of deafness accounts for 30% of hereditary deafness; the latter only has symptoms of deafness, accounting for 70% of hereditary deafness.

Introduction to hereditary deafness

Some of these patients do not respond to sound after birth. If they do not wear hearing aids and receive language training, they will not be able to communicate normally, but they will also hinder the normal intellectual development of deaf children and become a heavy burden on the family and society. Some patients only develop symptoms between the ages of 10 and 30 years. They show hearing loss, which increases with age, and eventually reaches severe deafness. Although these patients have learned to speak, they can't perform normal with others due to hearing impairment. I ca nt watch movies, TV, listen to radio, and music like normal people, which is a great pain for myself and my family.

With the advancement of modern science and technology and the rapid development of molecular genetics, people's understanding of hereditary deafness continues to deepen. It is believed that in the near future, the medical problem of hereditary deafness will be overcome and benefit the deaf patients.

The reader is reminded that if there are more than two deaf people in the family, they should go to the hospital as soon as possible to conduct examinations and consultations in order to rule out hereditary deafness as early as possible and to avoid the occurrence of deafness in the next generation.

Classification of hereditary deafness

The classification of hereditary deafness has not yet been unified. Here, only the genetic method, the location of the lesion, the time of onset, and the associated disease are described.

Hereditary deafness

Autosomal recessive deafness is a hereditary gene that is located on the autosome and is controlled by a recessive gene. This type of deafness occurs only when two alleles from each parent are deaf genes. Recessive hereditary deafness has so far accounted for 80% of single gene mutations. Although most do not develop the disease, carriers will pass the same genotype to 25% of their children. If a baby with a recessive recessive gene is the first person in the family to develop the disease, deafness can occur without detection because there are no other related systemic abnormalities and no family history of deafness.

Autosomal dominant widow's deafness refers to the inheritance of genetic genes located on autosomes and controlled by dominant genes. This type of deafness accounts for 10% -20% of genetic deafness, and infants can develop disease-causing genes from one of their parents. Deaf children can be the result of gene expression in the affected parent or a new gene mutation in the parent. Gene carriers are almost always patients, but the degree of clinical manifestations varies greatly between patients.

(3) Sex-linked genetic deafness genes are located on the X chromosome and transmitted with the X chromosome. This type of deafness accounts for 1% -2% of genetic deafness, including recessive and dominant inheritance. Women who have a deaf recessive gene on one of the x chromosomes have normal hearing, and heterozygous men pass it to all children. If it is recessive sex, half of men are affected. Women must be homozygous to be affected. Unaffected women become carriers of this genetic trait. In dominant inheritance, if the mother is deaf, about 1/2 of the children will develop the disease; if the father is sick, all the daughters will be sick.

. The incidence of mitochondrial gene mutations is low, and it is maternally inherited.

Location of hereditary deafness

The lesions are located in the outer and / or middle ears and cause conductive deafness, such as narrowing or atresia of the external auditory canal, deformities of the ossicle, and otosclerosis.

The lesion is located in the inner ear, causing sensorineural hearing loss.

Lesions involving the outer and / or middle and inner ears cause mixed deafness, which is rare.

Onset of hereditary deafness

Congenital deafness: Deafness that occurs after birth and does not develop after birth is congenital deafness.

Hereditary progressive deafness: At birth, all parts of the ear develop normally and hearing is normal, but progressive hearing loss begins at a certain age after birth and eventually develops into severe deafness.

Hereditary deafness associated with disease

Simple hereditary deafness: Deafness is the only inherited disease in the affected individual, and there is no genetic damage to other organs.

Deafness syndrome with genetic diseases of other organs: In addition to genetic deafness, patients also have genetic diseases of other organs of the body, such as the eye, skeletal system, nervous system, kidney, skin, endocrine system, metabolic diseases, etc. .

Hereditary deafness symptoms

According to the anatomical characteristics of the labyrinth, congenital deafness includes hereditary deafness and other non-hereditary deafness that has been shaped of the inner ear deformity before birth, and can be divided into 4 basic types.

Michel Hereditary deafness Michel type

(Agenesis type): This is the most serious inner ear malformation, which is characterized by partial or entire labyrinth development (including the cochlea and vestibule), and occasionally visible residual membrane labyrinth structure. Cochlear and vestibular nerves may be present or absent, and are generally not auditory.

Mondini Hereditary deafness Mondini

(Various deformities of bone and membrane labyrinth): autosomal dominant inheritance, cochlear vestibular hypoplasia, cochlea may be partially developed, usually only 1 and a half or 2 weeks at the base of the base, the balloon, oval capsule and semicircular canals can develop Malformations, snail nerves and vestibular nerves usually have ganglions or part of them. Patients may have residual hearing, but rarely verbal hearing is available.

Scheibe Hereditary deafness Scheibe

(Membranous labyrinth malformation): Bone labyrinth, membranous ellipsoid, and semicircular canals are well developed, but membranous volutes and balloons are underdeveloped, and volutes atrophy. The spiral organs and vascular veins showed undeveloped cord-like connective tissue, and the balloon wall collapsed on the hypoplasia of the sensory epithelium and otolith. This type is the most common among hereditary congenital deafness. The patient may have partial hearing.

Alexander Hereditary deafness Alexander type

(Moderate membrane labyrinth malformation): Cochlear dysplasia, the basal perihelix and its adjacent ganglia are the most affected, causing high-frequency hearing loss. Because of its low-frequency hearing, hearing aids can help.

Hereditary deafness simple deafness

More common, including mono and binaural deafness. Relative to the degree of genetic heterogeneity, deafness can be classified into three types: conductive, sensorineural, and mixed deafness according to the lesion site after clinical examination. Conductive deafness, which is caused by atresia of the external auditory canal, can be divided into 3 groups according to the degree of lesions. The first group has hypoplasia of the external auditory canal, small tympanic membrane, and the middle ear cavity is normal or small. ; The third group is the characteristics of the second group plus obvious hypoplasia of the middle ear cavity, or no middle ear cavity. Sensorineural hearing loss can be unilateral or bilateral, with severity ranging from mild to severe. For those who are deaf at birth, their cochlear lesions are generally stable and therefore non-progressive. The progressive cochlea develops normally at birth, and degenerative changes begin to occur at a certain age after birth. Because speech development is usually completed at the onset, patients are generally deaf and not dumb.

Hereditary deafness with other abnormal syndromes

1 Hereditary deafness 1) Accompanying skin system disorders

During embryonic development, skin, hair, fingernails, some pigments, inner ear and central nervous system all originate from the ectoderm. Therefore, deafness can be accompanied by abnormalities in the above organs. Wamdenburg syndrome (congenital deafness and white frontal syndrome): it is a more common form of congenital deafness, accounting for 2% -5% of all congenital deafness, mainly autosomal dominant inheritance, almost 100% Obvious, but the degree of expression varies. The clinical features are white hair on the forehead, widening of the nasal roots, internal and external movements, heterochromia and deafness, and hearing impairment can occur in 20% -30% of patients, unilaterally or bilaterally, to varying degrees. There are two types according to whether the internal condyle moves outward, and the internal ectoderm is type I, otherwise it is type . Other skin lesions accompanied by cochlear deafness: such as albinism, abnormal pigment, congenital non-allergic eczema, keratoderma, white nail disease, finger (toe) nail malnutrition, and tapered teeth.

2 Hereditary deafness 2) Accompanying eye diseases

Usher syndrome (deaf-mute, omental pigment degeneration syndrome): It is an autosomal recessive inherited disease, which is characterized by deaf-mute and retinal pigment degeneration. It is divided into three types: type I is manifested as severe deafness and lack of vestibular reaction Night blindness occurs in infancy or adolescence, and legal blindness occurs in early adulthood. Type manifests as congenital sensorineural deafness, the hearing curve is oblique, the vestibular function is normal, night blindness occurs in adolescence, and legal blindness occurs in early adulthood or middle age. Type is characterized by normal or moderate hearing impairment at birth, but it can develop later, the hearing curve shows a downward slope, vestibular dysfunction can develop, and the degree and progress of night blindness can vary. Hallgren syndrome: deafness with abnormal vestibular dysfunction; atypical progressive retinal pigment degeneration, resulting in reduced visual field and night blindness; multiple neuroinflammatory diseases such as cerebellar ataxia, ocular nystagmus, and muscular atrophy. Refsum syndrome (hereditary ataxia-polyneuritis syndrome): It is characterized by deafness, retinal pigment degeneration, polyneuritis, and psoriasis. Cockayne syndrome (retinal atrophy dwarf deafness syndrome): rare, characterized by deafness, retinal atrophy, mental retardation and dwarfism. Laurence-Moon-Bandet-Biedl syndrome (obese retinal pigment degeneration-multi-finger (toe) deformity): rare, characterized by deafness, mental retardation, obesity, multi-finger (toe) deformity and sexual dysfunction.

3 Hereditary deafness 3) accompanied by central nervous system disease

More rare. Hürler Syndrome (Strange Deafness Syndrome, Glycosaminoglycan Deposition IH Type): Sensorineural Deafness with Bone Deformation, Shortness, Blindness, and Splenomegaly. Deafness begins in infancy and gradually increases. Mild to moderate deafness can sometimes be accompanied by progressive mental decline and corneal opacity. Richards-Rundle syndrome: deafness with trunk ataxia, mental decline, hypogonadism. The child's hearing is completely lost by the age of 5-6.

4 Hereditary deafness 4) Accompanying maxillofacial and / or skeletal system disorders

This type of deafness is mostly transmissive, but if the lesion involves the inner ear, cochlear hearing loss can also occur.

Treacher Collins syndrome (maxillofacial dysplasia and deafness syndrome): autosomal dominant inheritance, showing different degrees of manifestation. Nearly 60% of cases can be caused by newly mutated genes, so they can be clinically sporadic. Its characteristics are: a. The condition of the skull is poor development of the upper orbital margin, poor development of the sacrum, even lacking but bilateral symmetry, poor gasification of the mastoid or obvious sclerosis, small or no development of the sinuses, excessively wide two orbital distances, and severe ankle process of the mandible. hypoplasia. b. Eyes show short palpebral fissures, external oblique obliques, and the outer 1/3 of the lower eyelid is usually absent. About half of the patients have less or absent eyelashes, and the lower punctum and meibomian glands may be absent. c. Ear deformities can be expressed as cup-shaped, oblique, or low to the angle of the mandible; most patients have a narrow and twisted external auditory canal, and about one-third of the patients can lack the external auditory canal; in most cases, the ear cavity is small and even filled with connective tissue Malformation of auditory ossicle, malformation or partial absence of vestibular cochlea; poor development of mastoid and even absence of air chamber. d. The nose is prominent due to dysplasia of the zygomatic arch and orbital bone. The nostrils are narrow and the nasal cartilage is poorly developed. Posterior nostril atresia has also been reported. e. The mouth showed different degrees of cleft palate and pharyngeal deformities. The giant mouth (transverse buccal cleft) can be unilateral or bilateral. f. Mental development is usually normal, but stunting has also been reported.

Goldenhar Syndrome: Also known as ocular vertebrae dysplasia, Goldenhar-Gorlin syndrome, first branchial arch syndrome, first and second branchial arch syndrome, bovine facial dysplasia, etc. Clinical features are various degrees of facial asymmetry; ipsilateral palpebral fissures can be present on the affected side; various degrees of auricle deformities, narrowing or occlusion of the external auditory canal, facial nerve pathology abnormalities, and skull base deformities; 5% -15% of cases have Mental retardation; lack of one side of the kidney, double ureter, renal ectopic, abnormal renal blood vessels, hydronephrosis of the kidney; smaller anterior and posterior diameter of the affected side and vertebral volume, anterior-inferior displacement of the temporomandibular joint, orbital shrinkage, and cervical fusion Unilateral transverse cheek fissure or pseudo transverse cheek fissure can be seen; heart, lung and gastrointestinal malformations have also been reported.

Klippel-Feil syndrome (neck-heel-auditory syndrome): It is characterized by abnormal bone development, including congenital short neck, cervical spine fusion, head deflection, scoliosis, and spina bifida, etc., about 1 / 4-1 / 2 Children with sensorineural and / or conductive deafness. Deafness can occur at birth and can delay onset. In patients with delayed onset, the degree of deafness and the development of hearing loss can vary widely.

Willebrand syndrome (neck-eye-ear syndrome): characterized by short and rigid neck (due to cervical fusion), low hairline, bilateral abductor nerve paralysis, and congenital sensorineural hearing loss. Madelung syndrome: characterized by short stature, short forearms, short legs, and multiple deformities of the wrist, tibia, and fibula. The patients were mostly women, and the ratio of male to female incidence was 1: 4. Most of them are conductive deafness caused by abnormal ossicular chain, but also sensorineural deafness.

5 Hereditary deafness 5) with other deformities

Pendred Syndrome (Congenital Goiter Deafness Syndrome): It is autosomal recessive, and the child is deaf at birth. In severe cases, it becomes deaf and dumb. It can also be delayed congenital progressive deafness. Goiter occurs mostly in adolescence, and it is also noticeable after adolescence, which is caused by abnormal iodine metabolism. Normal and hypothyroidism accounted for 50% each. DiGeorge syndrome (thymic dysplasia, III and IV pharyngeal sac syndrome): It is characterized by malformations of the third and fourth pharyngeal sacs, middle ear and inner ear, congenital thymus and parathyroid gland defects. Jervell-Lange-Nielsen syndrome (deafness, abnormal electrocardiogram syndrome): autosomal recessive, characterized by severe bilateral deafness, prolonged Q-T interval of ECG, recurrent syncope, and even sudden death.

(3) Chromosomal abnormalities: Down syndrome (trisomy 21, congenital fool type) is the most common chromosomal abnormality, and patients often have conductive deafness; E18-trisomy syndrome refers to the extra chromosome located in the first group of group E. 18 alignments. The clinical manifestations are low ears, ear deformities, small jaw, and index finger (forefinger) bent above the middle finger, the occipital bone protrudes, and patients usually die shortly after birth; D13-15trisomy syndrome, which means that extra chromosomes The 13th or 14th or 15th center of the group. Presented as low ears. Deformed outer ear, middle ear, inner ear, cleft lip, palate, small eyes, cryptorchidism, and heart disease. Children often die shortly after birth.

Hereditary deafness

Hereditary deafness

1) Familial sexual sensorineural hearing loss: Caused by degeneration of a well-developed cochlea. Deafness is often bilateral and usually begins in childhood (8-11 years) or early adulthood and gradually increases. Temporal bone slices can show degeneration or disappearance of the cochlear peribasal spiral and spiral ganglia, as well as irregular degeneration of blood vessel patterns. The hearing curve often shows high-frequency hearing loss, or it is flat or pelvic.

2 Hereditary deafness 2) otosclerosis

See the relevant chapters for details.

accompanied by other abnormal syndromes

1) Branchio-oto-renal syndrome (parotid, ear, kidney syndrome, BOR syndrome): autosomal dominant inheritance

Disease, manifestation to varying degrees. The clinical manifestations are gill cleft fistula or cyst, auricle malformation, hearing impairment and different degrees of renal malformation.

3Alport Hereditary deafness 3) Alport syndrome

(Familial hereditary hemorrhagic nephritis deafness syndrome): autosomal dominant or sexually linked dominant

Genetic disease, clinically characterized by glomerulonephritis and sensorineural hearing loss. Patients who have 3 of the following 4 criteria can be judged as having this syndrome. Family history of hematuria, or accompanied by renal failure. Electron microscopy of renal biopsy revealed glomerulonephritis. Eye signs, such as anterior cone lens, particles around the macula, cataracts, and ocular tremor. High-frequency hearing loss occurs during childhood and develops progressively.

4Pyle Hereditary deafness 4) Pyle disease

Cranial and metaphyseal dysplasia, hearing impairment is mostly conductive deaf, occasionally cochlear deafness, with open femur, skull changes similar to osteosclerosis, can occasionally cause cerebral nerve paralysis due to cranial foramen narrowing.

5 Hereditary deafness 5) other

Such as Hurler, Klippel-Feil, Refsum, Richards-Rundle and other syndromes can have delayed deafness.

Hereditary type of deafness

The chromosomes of human sperm and egg cells are carriers of genetic material. There are 23 pairs of 46 chromosomes in sperm and egg cells. Twenty-two of them are called autosomes, and the other one is symmetrical. Sex chromosomes determine sex, XY for men and XX for women. The characteristic of human genetic material is to be able to replicate itself accurately. In the transmission of inheritance, the concept of "gene" is cited. Genes are smaller units than chromosomes and cannot be observed under a microscope. The existence of genes can only be determined by genealogical analysis. There are three genetic types of congenital deafness:

Recessive inheritance of autosomal hereditary deafness

It means that the pathological gene carried by the parent is recessive, and the disease can be manifested only when the genes are paired (homozygous). This method is called autosomal recessive inheritance, and it is the main genetic method of congenital deafness.

Dominant inheritance of autosomal hereditary deafness

It means that the pathological gene carried by the parent is dominant. As long as one gene is passed to the offspring, the offspring will replicate the parent disease, that is, the individual will have the disease as long as there is a dominant pathogenic gene. If one of the parents has congenital genetic deafness, the child's risk of developing deafness is 50%.

Hereditary deafness with hereditary deafness

Refers to deafness genes not on autosomes but on sex chromosomes, which are also divided into dominant inheritance and recessive inheritance. If the genetic genes are combined on the X chromosome, children with recessive recessive deafness have 1/2 of their children deaf and the other 1/2 are carriers of the deafness gene; with sexual dominant deafness, all of their male children are deaf Patients, 1/2 women were deaf.

As mentioned above, no matter what kind of genetic deafness, the reappearance rate of more than 20% is highly dangerous; 10-20% is moderately dangerous;

Pelvic audiograms are more common in hereditary hearing loss

Below 10% is a low risk rate.

Treatment of hereditary deafness

Auditory nerve regeneration reduction therapy

^[1] 1. It has the effects of opening qi, tongluo, nourishing kidney, tongqiao, detoxification, activating blood, and ears. It uses targeted Chinese medicine prescriptions to tongluo detoxification, nourishing blood and removing stasis, nourishing yin and nourishing qi, and Chunxiang Kaiqiao Differential treatment of deafness and tinnitus.

2. It has the ability to clear the qi, improve the blood supply to the inner ear, enhance the metabolism in the ear, increase the excitability of hair cells, etc., open up blood circulation disorders, nutritionally regenerate ear cells, activate cochlear nerves, and repair and regenerate ear cells.

3. With promoting blood circulation, removing free radicals, repairing diseased cells, relieving earache pain, it can promote degeneration, atrophy, and necrosis of auditory nerve cells in a short period of time. After comprehensive and standardized treatment, tinnitus can be eliminated in a short time and normal hearing can be restored.

4. The method of local light wave treatment can regulate blood vessel function, accelerate blood flow and improve blood lymphatic circulation in the inner ear; strengthen tissue metabolism, correct hypoxia in the inner ear and timely discharge harmful substances, and promote the improvement and recovery of cochlea function and hearing function .

5. Electroacupuncture for deafness and tinnitus is a pulsed electromagnetic field that directly intervenes in the middle and inner ears of patients. Radio waves can improve local blood circulation, improve tissue permeability, improve cochlear blood supply, and help restore the normal physiological functions of the cochlea.