Sensorineural Hearing Loss in Hajdu-Cheney Syndrome

Sensorineural Hearing Loss in Hajdu-Cheney Syndrome

Hajdu-Cheney Syndrome (HCS) is a rare connective tissue disorder which was first described in 1948 [1]. Less than 50 cases have been reported in the medical literature. The majority of cases are sporadic however an autosomal dominant inheritance pattern has been recognized [2-4]. The main characteristics of HCS include acroosteolysis, shortened terminal phalanges, short stature, joint hypermobility, as well as micrognathia. Cranial findings include open cranial suture lines, basilar invagination, posterior fossa abnormalities and hydrocephalus [2,4]. Conductive hearing loss has been reported in association with HCS [2,4,5], however sensorineural hearing loss has never been described in the literature. In particular the correlation between the course of the eighth cranial nerve and its mechanical stretching as a possible cause of sensorineural hearing loss remains unclear. Recent research has confirmed that heterogenous mutation in the Notch2 gene is the cause for Hajdu-Cheney syndrome [6]. The Notch pathway plays a key role in the regulation of skeletal development and bone remodeling as well as inner ear cellular differentiation.It is possible that alterations of intracochlear cell structure may lead to inner and outer hair cell changes that could in turn account for sensorineural hearing loss (SNHL).