Is a clinical geneticist a useful addition to a pediatric hearing loss clinic?.

Abstract

Until the development of massive parallel sequencing, the ability to perform genetic testing in non-syndromic, heterogeneous conditions such as deafness, was limited. Clinicians had access to testing for connexion 26/30, imaging, and their clinical acumen, which in a small percentage of cases would reveal the diagnosis. Over 80 genes have now been discovered to be the cause of nonsyndromic deafness and many other genes to cause syndromic forms of deafness. A molecular diagnosis informs management and reproductive choices. We compared the diagnosis rate prior to clinical genetics (pre-2014) to after a clinical geneticist joined the deafness clinic (post-2014). 88 patients were seen by a single clinical geneticist from 2014 to 2016 with a clinical diagnosis of deafness. Patients were all children seen at a major metropolitan hospital in Melbourne, Australia. Patients had a clinical genetics assessment, and a subset were investigated further with molecular testing. The diagnosis rate by a single pediatrician was 25%, pre-2014. Post 2014, the diagnosis rate with a clinical geneticist was 44% due to increased syndrome recognition and the use of massive parallel sequencing gene panels for diagnosis. Clinical geneticists have a different skill set to pediatricians. They are trained to detect subtle dysmorphic features and recognise rare syndromes, but also to understand and advise on complex molecular testing. These data show that a clinical geneticist embedded in a pediatric hearing loss clinic can significantly increase the diagnosis rate, and thereby improve management and help inform reproductive choices for families.