Objective: Genetic studies show that consanguineous marriage can increase the probability of incidence of genetic impairments such as hearing impairments. The target of this study is to identify the prevalence of consanguinity among the parents of hearing impaired students in primary schools.

Materials and Methods: We selected all of deaf students of Tehran (614 students). Their mothers answered to questionnaires. The questions were about Risk Factors of deafness in mother pregnancy or in neonatal period.
Results: from 614 students, 389 parents of them (64%) had consanguineous marriage and 223 person (36%) didn&apost have this factor. 2 person did not answer to this question. In this study we observed that there is 32.3% family history of hearing loss, 29.2%deaf sister and brother, 17% ear infection history. Other risk factors were studied too. Also there is significant correlation between consanguinity and more than one deaf children in the family (p<0.005).
Conclusion: According to high incidence of consanguinity (64%)that was observed in this study it may be one of most important causes of sensory neural hearing loss in children, so we should give enough information about this problem to the people.

Background and Aim: Deafness is a heterogeneous disorder induced by genetic and environmental factors. It is the most common hereditary sensory-neural disorder that affects 1/1000 to 1/2000 of the newborns. More than 70% of hearing loss cases are caused by genetic disorders, 85% of which result from nonsyndromic autosomal recessive sensory-neural hearing loss. Up to now, more than 100 genes contributing in hearing loss have been determined. Alteration of these genes may result in hearing loss.
This study was performed to identify the inheritance patterns of deafness and its relation with ethnicity, gender and consanguineous marriages.
Methods: In this survey, data from 356 families affected by hearing loss and referred to welfare organization of Ahvaz during the time were collected based on sex, ethnic groups and relativeness.
Results: The results state a high frequency of autosomal recessive deafness caused by consanguineous marriages within Arab and non-Arab ethnic groups (p<0.05). But no significant difference in gender.
Conclusion: In conclusion, the high frequency of autosomal recessive deafness among the population with a high frequency of consanguineous marriages is considerable. The dominant pattern of deafness observed in this population was autosomal recessive.

Background and Aim: Having healthy non-handicapped children plays a major role in mental health of the family and decreases family and society&aposs costs. While consanguineous marriage could lead to expression of recessive genes and a variety of handicaps including deafness, the aim of present study was to scrutinize the prevalence of consanguineous marriage among parents of deaf and normal children as well as its relationship with deafness.
Methods: In this study, 467 couples parenting normal children were selected by cluster sampling from elementary, guidance and high schools of Ardabil city and 423 couples parenting disabled children were selected non-randomly among which 130 had deaf children. Descriptive statistics was used to determine the prevalence of consanguineous marriage and chi-square test to compare prevalence of consanguineous marriage among parents of normal and deaf children.
Results: Descriptive analyses showed that 80 out of 130 (61.54%) parents who had deaf children have had consanguineous marriage. Furthermore data analysis demonstrated that prevalence of consanguineous marriage was significantly higher among parents of deaf children (p<0.001).
Conclusion: Consanguineous marriage plays a major role in expression of recessive genes and could lead to development of various handicaps including deafness. Increasing couples&apos awareness about consequences of consanguineous marriage and conducting genetic counseling are indispensable.