Hereditary sensorineural hearing loss is a preventive disease. A rando
m sample survey of 6,421 Saudi infants and children was conducted to s
tudy the prevalence of consanguineous marriage and its effect on the p
revalence of hereditary sensorineural hearing loss. First cousin consa
nguineous marriage was found among the parents of 21.1% of the childre
n studied and second cousin consanguinity was present in 23%. The over
all prevalence of hereditary sensorineural hearing loss was 1.7%. A hi
gher prevalence of 2.8% of this type of deafness was found among child
ren of first cousin parents, compared with 1.6% among children of more
distant consanguinity and 1.4% among non-consanguineous families' chi
ldren. The study showed that consanguinity is widely practiced among t
he population surveyed and demonstrated a marked adverse effect on the
incidence of hereditary sensorineural hearing impairment.