Vergult et al1 present interesting and useful descriptions of three patients with deletions at 12q15. It would be helpful if they could clarify one point, however. The authors refer throughout the paper to ‘nasal’ speech. It is not clear from the description whether their patients have hypernasal speech or hyponasal speech.

Hypernasal speech occurs when there is escape of airflow and acoustic energy into the nasal cavity during speech, commonly due to dysfunction (mechanical or neuromuscular) of the velopharyngeal valving mechanism, as in velocardiofacial syndrome.2 Hyponasal speech, by contrast, is caused by reduced nasal cavity resonance during speech, usually due to anatomical obstruction of the nasal cavity. It is easy to demonstrate, by simply pinching the nose closed while speaking.

Distinguishing between these two abnormalities is important, both in diagnosis and in management of conditions in which they occur.