Most generally speaking, failure to reach language learning and noise response milestones in infants may indicate a possible case of congenital deafness (CD) and motivate further examinations [1].

CD appears as an isolated symptom in eighty percent of all reported cases of genetic CD. So far, genetic CD has been shown to be passed on in either an autosomal dominant, autosomal recessive or in an X-linked manner. Three out of four CD cases can be rationalized with an autosomal recessive inheritance mechanism. An example of an autosomal dominant presentation of nonsyndromic genetic CD involves a mutation in type XI collagen [1] [2].

In twenty percent of diagnosed genetic CD cases, CD presents together with a plethora of other symptoms in the context of highly complex disorders. Most frequent syndromes related with genetic CD are the Alport Syndrome, the Brancio-Oto-Renal Syndrome, the X-linked dominant Charcot Marie Tooth disease, X-linked hereditary axonal neuropathies, autosomal recessive demyelinating neuropathy, autosomal dominant hereditary neuropathies type I and II [3], Goldenhar Syndrome [4], Jervell and Lange-Nielsen Syndrome, X-linked recessive Mohr-Tranebjaerg Syndrome, Norrie Disease, Pendred Syndrome, Stickler Syndrome, Treacher Collins Syndrome, Waardenburg Syndrome, Usher Syndrome and in some cases mitochondria-related syndromes [5] [6] [7].

In twenty percent of overall cases, CD presents as an acquired disorder. Cochlear malformations are usually the main culprits for this manifestation of CD. A premature halt in cochleal development in embryos is often the starting point for Mondini dysplasia [8]. In a related anomaly, the CHARGE association (short-hand for "Coloboma, Heart disease, choanal Atresia, Retarded development, Genital hypoplasia, Ear anomalies") features hypoplasia of the external ear and progressive deafness. CHARGE patients suffer from a Mondini type deformity and an absence of semicircular canals [9]. Enlarged Vestibular Aqueduct Syndrome may also present with a fluctuating sensorineural loss of hearing [10].

• Disability

  The level of awareness on the issue of disability itself in India is abysmal. [mylittlemoppet.com]

  Mutations Impairing GSK3-Mediated MAF Phosphorylation Cause Cataract, Deafness, Intellectual Disability, Seizures, and a Down Syndrome-like Facies. Am J Hum Genet. 2015 May 7;96(5):816-25. [disorders.eyes.arizona.edu]

  He developed severe intellectual disability and epilepsy. MRI showed signal abnormalities in the posterior limbs of the internal capsules, thalami, and cerebral white matter. The abnormalities were progressive over time. [ncbi.nlm.nih.gov]

  Vaughan Key facts Around 466 million people worldwide have disabling hearing loss (1), and 34 million of these are children. It is estimated that by 2050 over 900 million people will have disabling hearing loss. [who.int]

• Falling

  It is estimated that between a quarter and half of all severe to profound hearing losses are due to hereditary/genetic causes and many fall into the congenital category. [hiddenhearing.co.uk]

  Although fluid in the middle ear usually results in only temporary hearing loss, chronic ear infection can cause a child to fall behind in language skills. [en.wikipedia.org]

• Family History of Deafness

  Causes of deafness before birth (pre-natal causes) Permanent deafness in children is most commonly caused by genetics, passed down in families, even though there appears to be no family history of deafness. [ndcs.org.uk]

  Parents are strongly advised to be aware of their family history of deafness and immediately consult a medical professional, if their child does not appropriately respond to noise. [symptoma.com]

  Children with deafness should be given the opportunity to learn sign language along with their families. [who.int]

  Approximately 10-20% of all deafness is acquired postnatally, although some genetic causes of deafness result in hearing loss that begins during childhood or adolescence. Risk factors Family history of deafness. [patient.info]

• Inflammation

  ACQUIRED CAUSES OF CONDUCTIVE DEAFNESS► Inflammation  Trauma  Foreign body► Wax► Otitis externa► ASOM► CSOM► OME 7. [slideshare.net]

  Learn More About Topic Swimmer's Ear Swimmer’s ear (also called acute otitis externa) is a painful condition that affects the outer ear and ear canal that is caused by infection, inflammation, or irritation. [entnet.org]

  External Otitis (Otitis Externa) External otitis is an inflammation of the external ear and/or ear canal. [cochlear.com]

  Corticosteroids may also be used to reduce cochlea hair cell swelling and inflammation after exposure to loud noise. [hearingloss.org]

• Asymptomatic

  Approximately 1 in 5 asymptomatic children with hearing loss exhibited progressive hearing loss, and 1 in 4 asymptomatic children with hearing loss experienced fluctuations. [pediatrics.aappublications.org]

  This study suggests asymptomatic rubella infection in the first trimester as an etiologic factor in congenital deafness. [nejm.org]

  If both parents carry the mutated Connexin 26 gene, all of their children will have a 25% chance of being born deaf, and 50 % will be asymptomatic carriers of the gene (like the parents). [californiaearinstitute.com]

  There is good speech discrimination and sometimes the hearing impairment may be asymptomatic as hearing at and below 2 kHz is predominantly affected. [bmb.oxfordjournals.org]

• Delayed Speech Development

  Parental concerns about possible hearing loss or observed delays in speech development require auditory screening in any child. [ncbi.nlm.nih.gov]

  […] if parents show concern about possible hearing loss or observe delays in speech development, even if their children have passed a newborn hearing screen. [nature.com]

• Dyspnea

  They presented with progressive dyspnea on exertion. Upon physical examination, both brothers had clubbing and/or cyanotic toes, normal fingers, and without facial, skeletal, ophthalmological, or mental abnormalities. [ncbi.nlm.nih.gov]

• Failure to Thrive

  Renal tubular acidosis and deafness Autosomal recessive ATPB6B1 Ion pump Distal renal tubular acidosis, presenting with acute dehydration, vomiting and failure to thrive. [bmb.oxfordjournals.org]

• Nausea

  He had attended his general practitioner with a 3-week history of oral thrush, nausea, weight loss, nocturia and pruritus. He did not complain of visual problems, rash or arthralgia and was not taking any medications. [academic.oup.com]

• Arthritis

  Food and Drug Administration to treat adults with active psoriatic arthritis, a condition associated. [diatume.duckdns.org]

  Arthritis You’ll need to declare your specific type of arthritis, eg. osteo, rheumatoid, psoriatic. Cancer You have to disclose this, even if you had it many years ago and you are in remission. [1cover.co.nz]

  […] palate (Pierre Robin sequence), under-developed midface The eyes and some forms of Stickler may have severe and progressive near-sightedness (myopia), cataracts & retinal detachment Other findings may include bone/joint disorders, early adult-onset arthritis [babyhearing.org]

  […] including diagnostic tests, consultations with fee-approved specialists and specialist treatment – including radiotherapy and chemotherapy What you're not covered for Chronic conditions We cannot cover incurable long-term illnesses such as diabetes, arthritis [aviva.co.uk]

• Visual Impairment

  Visual impairment in severe and profound sensorineural deafness. [smw.ch]

  Usher syndrome affects more than 50% of the deaf-blind in the United States. 44 It is of significance to note that the visual impairment from retinitis pigmentosa is usually not apparent in the first decade, thus making funduscopic examination before [nature.com]

• Hearing Impairment

  RESEARCH ON HEREDITARY DEAFNESS SYNDROMIC HEARING IMPAIRMENT There are more than 200 forms of syndromic hereditary hearing impairment. [medhelp.org]

  Three of 39 hearing impaired subjects were excluded; one due to insufficient information on the probable cause of the hearing impairment and the other two due to a non-genetic origin of the hearing deficit. [nature.com]

  Newborns from across Victoria diagnosed with permanent hearing impairment in both ears of moderate or greater severity are being offered genomic sequencing in addition to their usual care. Congenital deafness is hearing loss present at birth. [melbournegenomics.org.au]

  childhood-onset hearing impairment. [bmb.oxfordjournals.org]

• Tinnitus

  The latter relates to the emergence of tinnitus in these subjects. The reviewed material is consistent with the hypothesis that tinnitus requires an established and actively used somatotopic map that leads to a corresponding somatic memory. [ncbi.nlm.nih.gov]

  Can You Prevent Tinnitus Links Between Hearing Loss And Tinnitus Tinnitus Causes Tips For Dealing With Tinnitus About What Makes Us Different Contact Us Dr Hilary Bio Free 5 Star Service Aftercare Aftercare Roadmap Free Lifetime Hearing Care Service [hiddenhearing.co.uk]

  Learn More About Topic Tinnitus Over 50 million Americans have experienced tinnitus, or ringing in ears, which is the perception of sound without an external source being present. [entnet.org]

  Tinnitus is not an illness or disease. Some of the triggers of tinnitus include middle ear infections and damage to the ear from loud noises. Tinnitus may occur on its own, or in conjunction with hearing loss. [betterhealth.vic.gov.au]

  Symptoms include hearing loss, which is usually partial and involving high-pitched sounds, and ringing in the ear or tinnitus 14. Hearing loss caused by acoustic trauma may worsen over time. [cochlear.com]

• Hearing Problem

  Hearing Loss Genetic Hearing Loss Noise Induced Hearing Loss Bilateral Hearing Loss Unilateral Hearing Loss Conductive Hearing Loss High Frequency Hearing Loss Low Frequency Hearing Loss Sensorineural Hearing Loss Hearing Problems Fungal Ear Infections [hiddenhearing.co.uk]

  While these signs don't necessarily mean that your child has a hearing problem, they could be indicators of one. [pamf.org]

  Social activities may be more challenging than it is for children with no hearing problems. The symptoms of hearing impairment depend on its cause. [medicalnewstoday.com]

  Screening tests for the GJB2 gene are available for at-risk people to help them determine their risk of having a child with hearing problems. [entnet.org]

  If there is damage or a structural problem with the eardrum or ossicles, surgery may help to repair it. If the problem is with the cochlea or hearing nerve, a hearing aid or cochlear implant may be recommended. [kidshealth.org]

• Social Isolation

  Congenital deafness can occur in infants and children at any age and is characterized by a reduced noise response that can lead to increased social isolation and lack of success at school. [symptoma.com]

  As a result, children with prelingual deafness risk becoming socially isolated, unless they attend a school that has a well-run special needs department with other children who have the same condition. [medicalnewstoday.com]

• Hematuria

  Renal disease includes nephrotic syndrome, renal dysplasia, hypoplasia or aplasia, chronic renal failure, hematuria, proteinuria and others. The frequency is unknown, but the disease is considered to be very rare. [dizziness-and-balance.com]

  Alport syndrome 7 COL4A5 COL4A3 7 COL4A4 7 SN Typically after age 10 yrs Varying severity; progressive Renal, cochlear, ocular involvement W/out treatment, renal disease progresses from microscopic hematuria to proteinuria, progressive renal insufficiency [ncbi.nlm.nih.gov]

• Vertigo

  Benign Paroxysmal Positional Vertigo (BPPV) Benign paroxysmal positional vertigo, or BPPV, is the most common inner ear problem and cause of vertigo, or false sense of spinning. [entnet.org]

  If the vertigo is not medically controlled, then various surgical procedures are used to eliminate the vertigo. [hearingloss.org]

  The hearing loss often starts as a sudden drop in hearing in one ear and sufferers may also experience tinnitus, aural fullness and/or vertigo. Anyone with symptoms should seek urgent medical care. [cochlear.com]

  There is no association of Alports and vertigo. Barakat Syndrome (text courtesy of Dr. Barakat). [dizziness-and-balance.com]

• Irritability

  Learn More About Topic Swimmer's Ear Swimmer’s ear (also called acute otitis externa) is a painful condition that affects the outer ear and ear canal that is caused by infection, inflammation, or irritation. [entnet.org]

• Screaming

  The impact on lung development of factors such as talking and screaming has not previously been investigated. [ncbi.nlm.nih.gov]

An audiometric test is the logical starting point to build a diagnosis. Patients with slowly progressing hearing loss should be checked for Alport Syndrome, Stickler Syndrome and Pendred Syndrome with a particular focus on a computed tomography (CT) investigation of the temporal bone. In infants, which are nonresponsive to noise, an auditory brainstem response (ABR) test should be considered. If hearing loss occurs as an isolated symptom, CD may be genetically caused. In this case, a thorough analysis of the patient's family history is highly recommended. In order to identify the specific mutation causing genetic CD, molecular genetic tests can screen for pathological mutations [11] [12].

If the cause of a diagnosed hearing loss remains unidentified, a clinical examination of the ear anatomy and other features linked to syndromic deafness is necessary. Checks should mainly focus on branchial cleft pits, cysts, preauricular pits, telecanthus, white forelock, pigmentary anomalies, goiter, craniofacial anomalies, heterochromia iridis and pigmentary retinopathy [13].

Fast or slowly progressing hearing loss can be caused by temporal bone anomalies, neoplasms, immunology-related deafness, trauma, infections (syphilis, Lyme disease) and other disturbances. A temporal bone CT scan will be able to detect malformations of the inner ear like Mondini deformities, Michel aplasia, a dilated vestibular aqueduct and a dilation of the internal auditory canal. If a CT scan of the temporal bones reveals an enlarged/dilated vestibular aqueduct or Mondini dysplasia, screening for pathogenic variants of SLC26A4 is advisable [13].

In families accumulating autosomal dominant CD, it may be useful to devise computer algorithms to screen for candidate mutations by selective audioprofiling [14]. High-throughput multi-gene assays may also provide a useful and time-efficient means for a reliable diagnosis [15].

A histological examination of the temporal bone may also be taken into consideration as a last resort.

Treatment of CD typically involves an expert team of specialized otolaryngologists, audiologists, clinical geneticists and pediatricians. It is also recommended to consult neurologists, pediatric ophthalmologists and sign language educators in selected cases. CD patients should be provided with hearing aids, if necessary. In severe cases of hearing loss in the pre-lingual stage, cochlear implants are highly advisable for children older than twelve months [16] [17].

In case of a diagnosed Pendred Syndrome with abnormal thyroid function, a thyroid hormone replacement therapy should be prescribed [13]. Young CD patients with moderate hearing loss and their families should take lip-reading and sign language classes as soon as possible to maintain active communication. Students suffering from CD will likely require special attention of their teachers [13].

Semiannual audiometric checks and consultations with an otolaryngologist are reasonable to track the stability and/or progression of CD.

A proper treatment of CD starting as early as possible is the best guarantee for a life without social restrictions.

Untreated CD in children may lead to difficulties in sound localization and in discerning sounds from background noise. In severe cases, children will suffer a life-long limitation of their language, reading and math skills. These children face an increased risk of school failure, language barriers, fewer opportunities for success and financial wealth and, therefore, a significantly reduced quality of life [13].

While CD can be caused by a variety of genetic mutations, there are also nongenetic factors that involve pre-, peri- and postnatal irregularities, which account for up to twenty percent of diagnosed CD cases. So far, the following pregnancy-related causes have been identified: maternal infections with rubella, cytomegalovirus, syphilis, HIV or herpes simplex, infant prematurity, low birth weight, birth injuries, severe hyperbilirubinaemia and sepsis, maternal drug (cocaine, streptomycine) and/or alcohol consumption during pregnancy, Rhesus factor complications during birth, jaundice, maternal diabetes as well as toxemia and anoxia in utero [18].

Genetic CD has been traced back to a large but still incomplete set of protein mutations. In the majority of cases, mutations of the gap junction proteins connexin-26 and connexin-30 encoded in the gene GJB2 and GJB6, respectively, are responsible for the manifestation of genetic CD [18]. A comprehensive review of currently known CD-related mutations can be retrieved from the Hereditary Hearing Loss platform [19].

CD has a prevalence of 1 in 2 000 infants. Genetic CD with autosomal recessive inheritance is the most frequent manifestation. Non-inherited abnormalities of the inner ear account for roughly 20% of all CD cases. Genetic CD affects different ethnicities with different mutations. For instance, connexin-related hearing loss in Hispanic infants has been reported to be less frequent than in other ethnic groups [20]. Male infants have a larger probability to suffer from the autosomal dominant manifestation of genetic CD [21].

In genetic CD, mutations of the connexin protein family have a detrimental effect on the temporal bone and on structural elements of the inner ear leading to a large set of abnormalities. Partial or complete loss of hair cells, and impaired functions of supporting cells, spiral ligaments, stria vascularis, the basilar membrane, spiral ganglion cells and of the auditory nerve have been reported in histological studies [19] [22]. In many cases, CD is caused by an impaired or completely absent mechanical excitability of audiosensitive hair cells [23].

CD can also progress with age or as a consequence of environmental influences such as excessive noise exposure.

A healthy maternal lifestyle during pregnancy is a major factor to prevent acquired CD. Prenatal audiometric tests may be an option. In genetic CD, parents should be aware of their family disease history and should immediately seek medical advice, if the infant does not respond to sounds and noises appropriately. Ignoring the early onset of symptoms will likely have disadvantageous long-term consequences for the child.

In case of diagnosed CD with professional support providing adequate hearing aids, patients are strongly advised to avoid noisy environments and loud music at any time in order to preserve hearing function.

Congenital deafness is either genetically caused or acquired in utero through maternal lifestyle and/or infection. The earliest symptom in infants is an impaired sound response and can start at any time in the pre-lingual phase. In the majority of cases, Congenital Deafness is caused by a genetic mutation of the connexin protein family. Diagnosis should start with an audiometric test. A detailed analysis of the family history and CT scans of the temporal bone as well as molecular genetic tests are strongly recommended. A multidisciplinary team of experts will be necessary to consult on adequate treatments (e.g. cochlear implants) and training (e.g. sign language classes) for the child and its whole family.

Congenital deafness can occur in infants and children at any age and is characterized by a reduced noise response that can lead to increased social isolation and lack of success at school. Parents are strongly advised to be aware of their family history of deafness and immediately consult a medical professional, if their child does not appropriately respond to noise. You may need to learn sign language in order to be able to communicate with your child, if the disorder is progressing fast. Avoiding loud noises is imperative to stabilize hearing functions, but not a guarantee.

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