What are the other Names for this Condition? (Also known as/Synonyms)

• Hearing Loss Insensitivity to Aldosterone
• Tunglang Savage Bellman Syndrome

What is Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome? (Definition/Background Information)

• Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome is characterized by bilateral moderate-to-severe sensorineural hearing loss and salivary gland insensitivity to aldosterone resulting in hyponatremia
• The disorder has been described in two brothers
• The transmission of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome appeared to be autosomal recessive

(Source: Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Who gets Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome? (Age and Sex Distribution)

• Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome is a rare congenital disorder. The presentation of symptoms typically occur in infancy
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome? (Predisposing Factors)

• A positive family history may be an important risk factor, since Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome can be inherited
• Currently, no other risk factors have been clearly identified for the syndrome

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome? (Etiology)

• The cause of development of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome is not clearly known
• The disorder is believed to be inherited in an autosomal recessive manner

Autosomal recessive inheritance: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome?

The signs and symptoms of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome may include the following:

• Low levels of sodium in blood, which can cause:
  • Headaches
  • Nausea
  • Dizziness, confusion
  • Weakness, fatigue
• Elevated plasma aldosterone levels
• Increased activity of renin in plasma
• Increased sodium concentration in saliva
• Elevated sodium levels (upper normal range) in sweat
• Presence of fluid in the middle ear
• Hearing loss in both ears, which may vary in severity among affected individuals

How is Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome Diagnosed?

Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Blood tests to check for the following:
  • Sodium levels
  • Renin activity in plasma
  • Plasma aldosterone levels
• Laboratory tests to check for elevated sodium in saliva and sweat
• Tests to ascertain/confirm hearing loss:
  • Otoscopy: Examination using an instrument that allows the physician to look inside the ear
  • Weber test: A test in which a vibrating tuning fork is placed on the midline of the head
  • Rinne test: A test in which a vibrating tuning fork is held next to the ear and then in front of the ear, until the individual no longer hears the sound
  • Audiometric test: Hearing tests that involve listening to different tones
  • Tympanometry: A test that puts air pressure in the ear canal in order to move the eardrum, and then measures the eardrum mobility (movement)
  • Acoustic reflex: A test that stimulates the stapedius (a tiny ear muscle) to move, in response to a loud sound
  • Static acoustic measures: A test that measures the amount of air in the ear canal
  • CT scan or MRI scan of the head
  • Auditory brainstem response: A test that places electrodes on the scalp and measures the electrical response of the brain to sounds
  • Otoacoustic emissions: A test in which a tiny microphone is placed in the ear, plays sounds, and measures the signals produced by the inner ear
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome?

The complications of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome may include:

• Severe loss of hearing
• Depression
• Withdrawal from society, due to hearing problems
• Coma, resulting from untreated hyponatremia

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome Treated?

• There is no cure for Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complication that develops
• Sodium supplementation to balance sodium levels in the body 
• Use of a hearing aid or cochlear implant to improve hearing

How can Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome be Prevented?

Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome may not be preventable, since it is a genetic disorder.

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome? (Outcomes/Resolutions)

• The prognosis of Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Hearing Loss-Familial Salivary Gland Insensitivity to Aldosterone Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/