Appeal by the employer and its insurance carrier from a decision of the Workmen’s Compensation Board which sustained an award for a permanent partial disability. While driving an automobile in the course of his employment on January 30, 1969, the claimant was involved in an accident and suffered a cerebral concussion, multiple contusions and abrasions and a severely sprained dorsal spine. The board, affirming the referee, found “that claimant has a continuing 33%% causally related disability ”. The appellants contend that the board’s finding is not supported by substantial evidence and that, even if claimant does have a partial permanent disability, his current physical problems are due solely to Huntington’s chorea, a hereditary and progressive neurological disease. Perusal of the record, in reference to both of these contentions, does reveal an abundance of divergent medical testimony, but it is well established that when the board is presented with conflicting medical opinions it must necessarily choose between those opinions, and its choice must be affirmed, if supported by substantial evidence (Matter of Grisanti v. Rugby Knitting Mills, 40 A D 2d 1047). Here, the board found multiple disabling causes: permanent injury from the accident and the hereditary Huntington’s chorea. In such a situation, “the apportionment of' causality is particularly within the board’s fact-finding province” (Matter of Benz v. Ralph Racking Go., 42 A D 2d 1006, mot. for lv. to app. den. 33 N Y 2d 520). Since the board’s findings are supported by substantial evidence, they must be affirmed. Decision affirmed, with costs to the Workmen’s Compensation Board. Greenblott, J. P., Cooke, Kane, Main and Reynolds, JJ., concur.