What is Townes Brocks Syndrome?
Townes-Brocks Syndrome is a rare genetic pathological condition the main characteristic of which is an absence of an anal opening. Additionally, an individual with this condition will have abnormal ears causing hearing deficit and deformed thumbs.
In some cases there are abnormalities noted in the kidneys, heart, and the lower extremities also. Townes-Brocks Syndrome is an autosomal dominant trait meaning that one copy of the faulty gene from any parent is enough for a child to develop Townes-Brocks Syndrome. Mutation of the SALL1 gene is the main cause behind development of Townes-Brocks Syndrome.
What Are The Causes Of Townes Brocks Syndrome?
As stated, mutation in the SALL1 gene is the main cause for development of Townes-Brocks Syndrome. It follows an autosomal dominant trait meaning that only one copy of this defective gene is enough for an individual to have Townes-Brocks Syndrome.
In some cases, Townes-Brocks Syndrome may develop as a result of spontaneous mutation in the SALL1 gene. It is estimated that about half of the cases of Townes-Brocks Syndrome are due to random or sporadic mutations in the gene responsible for causing Townes-Brocks Syndrome.
It is believed that many of the genetic conditions are caused due to consanguineous marriages meaning marriage between two people who are first degree relatives and this is also one of the causes of the mutation in the gene that causes Townes-Brocks Syndrome.
What Are The Symptoms Of Townes Brocks Syndrome?
The most prominent presenting feature of Townes-Brocks Syndrome is the absence of an anal opening. Additionally, abnormally low set ears with congenital hearing loss are also one of the presenting symptoms for Townes-Brocks Syndrome. The hearing loss can be moderate to severe and are usually progressive.
In addition, children with Townes-Brocks Syndrome will also have thumb deformity with the thumb having three bones instead of the normal two bones and even duplicated thumbs. Rarely, a child with Townes-Brocks Syndrome will have abnormalities of the lower extremities, especially the feet with a short third toe and flatfeet.
Renal dysfunction is also one of the features associated with Townes-Brocks Syndrome. A child with Townes-Brocks Syndrome may have rotated kidneys, polycystic kidneys, or in some cases underdeveloped kidneys.
Also associated with Townes-Brocks Syndrome are abnormalities associated with heart, eyes, and the spinal cord. Mental impairment is also seen in rare cases of Townes-Brocks Syndrome.
How Is Townes Brocks Syndrome Diagnosed?
The presenting feature of an absence of anal opening is the giveaway sign that the child is suffering from Townes-Brocks Syndrome. Additionally, other clinical manifestations of this condition are also seen.
Once this condition is suspected, then genetic testing can be done which will clearly show mutation in SALL1 gene which will confirm the diagnosis of Townes-Brocks Syndrome.
How Is Townes Brocks Syndrome Treated?
Surgery is the mainstay of treatment for Townes-Brocks Syndrome. A surgery will be required to make an anal opening. Periodic hearing evaluations need to be done to check the status of the hearing deficit associated with Townes-Brocks Syndrome.
In cases where hearing deficits cannot be repaired then the patient may be given hearing aids to help assist in hearing so as to make the patient more independent.
Additionally, periodic kidney function tests also need to be done to check on the status of the kidney and if any abnormality is found then appropriate treatment is rendered for treatment of kidney dysfunction associated with Townes-Brocks Syndrome.