Parental Consanguinity and Risk for Childhood Hearing Loss: A Retrospective Cohort Study

Genetic causes are responsible for half of the cases of hearing loss, most of them being the result of non-syndromic genetic changes resulting from autosomal recessive inheritance. Parental consanguinity might be an indicator to consider in the diagnosis of these cases. The aim of this study was to assess its importance as a risk factor for childhood hearing loss.

A retrospective cohort study conducted in a district hospital, between 2014 and 2018. We included all live births born during this period and excluded those with risk factors for childhood hearing loss other than parental consanguinity and those without hearing screening. We formed two study groups: newborns with parental consanguinity and newborns without risk factors. All the participants underwent hearing screening with the primary outcome of this study being the result of the screening. Those with a not normal result or with parental consanguinity also underwent diagnostic audiological evaluation.

Among 8513 live births, we studied 96 newborns with first-degree parental consanguinity and 96 newborns without risk factors. We found a statistically significant difference (p = 0.007) between the groups, with a 'refer' screening result rate of 24% in the group with parental consanguinity and 9.4% in the group without risk factors. We diagnosed one case of sensorineural hearing loss and another of mixed hearing loss in the first group and none of these cases in the second.

Parental consanguinity was associated with a higher risk of a refer screening result in newborns, which suggests the need to consider this as a risk factor for childhood hearing loss.