advertisement

Hearing management

Updated 07 December 2017

Gene breakthrough in rare disorder causing deafness

COMMAD, a syndrome that causes a number of birth defects, occurs when children inherit two genetic mutations, one from each parent.

0

Researchers say they have found the genetic cause of a rare disorder that causes children to be born with deafness, blindness, albinism and fragile bones.

The syndrome is called COMMAD. It occurs when children inherit two mutations – one from each parent – of a gene called MITF. Each parent is also deaf due to another rare genetic disorder called Waardenburg syndrome 2A.

Role of MITF

Further research is needed to learn more about the role of MITF during early development and how mutations in this gene result in the development of Waardenburg 2A and COMMAD, said researchers from the US National Eye Institute (NEI).

The study was published in the American Journal of Human Genetics.

COMMAD stands for the names of a number of conditions that affect people with this disorder. It includes:

  • Missing tissue around the eye
  • Abnormally dense bones prone to fracture
  • Small or abnormally formed eyes
  • An abnormally large head
  • Albinism (lack of melanin in the skin, eyes and hair)
  • Deafness

How to identify the cause

Identifying the genetic cause of COMMAD is important because deaf people commonly choose to marry other deaf persons. People who are deaf may not know that their deafness is associated with Waardenburg 2A, the researchers explained.

Deaf couples may want to consider genetic counselling prior to conceiving a child. If both potential parents have Waardenburg 2A, they risk passing mutated versions of MITF to their children, who would then have COMMAD, study lead author Dr Brian Brooks said in a NEI news release.

Brooks is chief of the NEI's Paediatric, Developmental, and Genetic Ophthalmology section.

The study describes two unrelated cases of children born with COMMAD who inherited the two mutations of MITF from their parents.

Most people who are born deaf don't have Waardenburg 2A. Along with hearing loss, people with the syndrome have premature greying of the hair, blue eyes, fair skin and sometimes vision problems, the researchers said.

Read More:

6 hearing stories you should read

Pop goes that balloon – and maybe also your hearing

Diabetes impairs hearing

 

Ask the Expert

Hearing Expert

Dr Kara Hoffman graduated from UCT in 2004, thereafter she completed her year of community service in Durban. In 2010 she completed her Masters Degree in Paediatric Aural Rehabilitation from UKZN. In 2016, she became a Doctor of Audiology through the University of Arizona (ATSU). Dr Hoffman and her partner Lauren Thompson opened a fully diagnostic audiology practice called Thompson & Hoffman Audiology Inc. In 2011 with world-class technology and equipment to be able to offer the broad public all hearing-related services including hearing testing for adults and babies, vestibular (balance) assessments and rehabilitation, industrial audiology, hearing devices, central auditory processing assessments for school-aged children, school screening, neonatal hearing screening programmes at Alberlito and Parklands Hospital, cochlear implants and other implantable devices, medicolegal assessments and advanced electroacoustic assessments of hearing. Thompson and Hoffman Audiology Inc. are based at Alberlito Hospital in Ballito, St Augustines Hospital in Durban and at 345 Essenwood Road, Musgrave. The practices are all wheelchair friendly. There are three audiologists that practice from Thompson & Hoffman – including Dr Kara Hoffman, Lauren Thompson & Minette Lister. The practice boasts professional, highly qualified, and extensive diagnostic services where all your hearing healthcare needs can be met. The additional licensing in vestibular assessment and rehabilitation, paediatric rehabilitation and cochlear implantation places this practice in one of the top specialist audiological positions in South Africa, with a wealth of experience in all clinical areas of audiology and is a very well respected and sought-after practice.

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules