Sight, hearing, smell, and pain


The structure of the eyes (lens, iris) of children with PTHS is usually normal. About 10% of children may have blocked tear ducts. If it causes prolonged problems it can be treated in the usual way.

Sight issues are common, with about two thirds of children with PTHS needing glasses, often before the age of 2.

The most common sight problems are:

* short-sightedness (myopia) 50%

* cross-eyes (strabismus) 45%

* eyes moving rapidly from side to side (nystagmus) 14%.

In rare cases a child will have wide pupils that react slowly to light. As sight problems are so common in PTHS, every child should be seen by an opthamologist at a young age and regularly followed up.


Only about 10% of people with Pitt-Hopkins syndrome have hearing loss. However, as it is so important for speech development, it is wise to check the hearing in all children with PTHS. There are tests that can be carried out that do not need any type of feedback from the child (in medical terms, optoacoustic emission and auditory evoked potential), so testing can be done reliably in every child, including the ones who are not willing or able to cooperate.


There have been no studies of the sense of smell in children with PTHS. Possibly some have a decreased sense of smell and others are sensitive to some smells, but this is not yet certain.


Recognising and dealing with pain is challenging in children and adults with PTHS as the majority can’t tell us this. From what we know it seems they can react in a different way to pain. Some parents have said that their child is more bothered by and sensitive to minor pain, such as a small scrape or cut, while they seem less bothered by something others would find far more painful such as pain after surgery. Others are showing less pain generally. This is important to realise if the behaviour of a child has changed as for instance a broken bone can go unnoticed. It may be that people with Pitt-Hopkins experience pain in a different way, with a different sensation: the gene that is affected, TCF4, makes a protein that works in pain signalling in the Pitt-Hopkins mouse.

There are questionnaires that have been developed to recognise and assess pain in children with special needs (such as the FLACC pain scale). Health care professionals caring for children with PTHS should use them if there is any doubt whether or not the child is in pain.


13/ Every child with PTHS should have their eye sight checked on diagnosis and then regularly monitored.

14/ Everyone with PTHS should have their hearing tested regularly.

15/ Parents and carers should be aware of the various types of pain felt by those with PTHS; if in doubt, there are special questionnaires that can help assess pain.

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