title: Consanguinity Among Parents of Iranian Deaf Children.
abstract: BACKGROUND
  It seems that there is a relationship between consanguinity and profound hearing loss but there is little data about the association of consanguinity and hearing loss in Iran.
  
  
  OBJECTIVE
  The aim of this study is to demonstrate the causes of profound bilateral sensorineural hearing loss among Iranian samples who are candidates for cochlear implantation.
  
  
  METHODS
  This study was retrospective, analytical, and designed to collect information about profound hearing impaired cases referred to the Baqiyatallah Cochlear implantation center using enumeration. A total of 310 children with profound hearing impairments participated in this study. They were aged from 6 months to 4 years old. The study was done between January 2007 and April 2009. Chi-square tests were used to show whether there was any statistical difference between the incidence of marital consanguinity of their parents and the normal population.
  
  
  RESULTS
  Sixty-five percent of those 310 children had parents who had married with their relatives. Of the 203 (65%) parents that had consanguineous marriages, 132 were first cousins, which includes the children of two brothers (37 [11.8%] patrilateral parallel cousins), the children of two sisters (38 [12.2%] multi-lateral parallel cousins), or the children of a brother and a sister (57 [18.3%] cross cousins). Fifty-four (17.4%) of the parents were second cousins and 17 (5.2%) were beyond second cousins. Also, hearing loss etiology was obvious in 237 (76.3%) of the patients with profound hearing loss but was unknown in 73 (23.7%). Hereditary was identified as the most common cause in 33% of the cases.
  
  
  CONCLUSIONS
  Our data demonstrated a 65% occurrence of consanguineous marriage among the parents of deaf children, which is statistically different from the percentage of consanguineous marriage among Iranian population (38%). This indicates an obvious relationship between severe hearing loss and consanguineous marriage.
authors.affiliation: New Hearing Technologies Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ajallouyan
authors.affiliation: New Hearing Technologies Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Shokofeh
authors.initials: S
authors.lastname: Radfar
authors.affiliation: New Hearing Technologies Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Sima
authors.initials: S
authors.lastname: Nouhi
authors.affiliation: New Hearing Technologies Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Seid Abbas
authors.initials: SA
authors.lastname: Tavallaie
authors.affiliation: New Hearing Technologies Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Susan
authors.initials: S
authors.lastname: Amirsalari
authors.affiliation: New Hearing Technologies Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Jaleh
authors.initials: J
authors.lastname: Yousefi
authors.affiliation: New Hearing Technologies Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Hasanali Fard
keywords: Children; Cochlear Implantation; Consanguinity; Hearing Loss