Theangiotensin-convertingenzymegeneisacandidategeneofstroke.Thepresentstudyinvolved62healthyvolunteersand148patientswithmiddlecerebralarterystenosisasconfirmedbybraincolorultrasoundfromaHanpopulationinNorthChina,anddeterminedtheperipheralbloodangiotensin-convertingenzymegenotypeusingPCR-restrictionfragmentlengthpolymorphismanalysis.TheresultsshowedthatthefrequenciesoftheDDgenotypeandDallelewereincreasedinpatientswithmiddlecerebralarterystenosis,butthedifferencewasnotstatisticallysignificantcomparedwithhealthycontrols.ThefindingsofthisstudyontherelationshipbetweenstrokegenesandmiddlecerebralarterystenosisindicatenosignificantcorrelationbetweenthefrequenciesoftheDDgenotypeandDalleleofangiotensin-convertingenzymeandmiddlecerebralarterystenosisinthisHanpopulationfromNorthChina.Inthefuture,studieswillbecarriedouttoinvestigatecorrelationsbetweenmultiplestrokecandidategenesynergyandmiddlecerebralarterystenosistoprovideafoundationforthedevelopmentofgenetherapy.