BACKGROUND: Asthma is an inflammatory airway disease caused by interaction 
between susceptibility genes and diverse environmental factors. In Israel, 
asthma seems to be familial and more severe in patients of Iraqi Jewish descent. 
On the other hand, asthma is less frequent in individuals with familial 
Mediterranean fever, an autoinflammatory disease prevalent in the Iraqi Jewish 
community and linked to mutations in the familial Mediterranean fever gene, 
designated MEFV.
OBJECTIVES: To explore a possible role for mutated MEFV in the reduced 
susceptibility to asthma and to determine its expression in Israeli subjects of 
Iraqi origins.
METHODS: Using a case-control approach, we studied the presence of the 3 most 
common MEFV mutations (M694V, V726A, and E148Q) in DNA samples from 75 patients 
with asthma and 45 asymptomatic first-degree relatives, all of Iraqi Jewish 
origin. The severity of asthma was evaluated using a published severity score.
RESULTS: Eleven patients with asthma and 14 of their relatives carried 1 or 2 
mutations in the MEFV gene, a carrier rate significantly lower in patients with 
asthma than in their first-degree relatives and in ethnically matched healthy 
individuals (P < .03 and P < .003, respectively). Carriers of MEFV mutations had 
less severe disease, compared with noncarriers (P < .002).
CONCLUSION: These findings suggest that MEFV mutations may have a protective 
effect in the pathogenesis of asthma.