—In an action to recover damages for medical malpractice, the defendants Elizabeth C. Salter, as executrix of the estate of Hiram P. Salter, Jr., and Sylvia N. Gregory, as executrix of the estate of John R. Gregory, appeal, and the defendant Jerome Strachman separately appeals, from an order of the Supreme Court, Westchester County (Donovan, J.), entered November 2, 1994, which denied their motions for summary judgment dismissing the complaint insofar as asserted against them.

Ordered that the order is reversed, on the law, with one bill of costs, the appellants’ motions are granted, and the complaint is dismissed insofar as asserted against the appellants.

The Supreme Court erred in failing to grant the appellants’ motions. The affidavit of the plaintiffs’ expert which contained conclusory assertions that the injured plaintiff’s injuries were the result of improper nourishment, hydration, and inadequate oxygen therapy, failed to meet the plaintiffs’ burden of supplying proof sufficient to rebut the affidavits submitted by the defendants in support of their motions for summary judgment. Those affidavits by a neonatalist and a geneticist stating their opinions and the factual bases therefor established that the nature and extent of the injured plaintiff’s disability could not have resulted from the post-birth care by the appellants, but was characteristic of a genetic defect (see, Alvarez v Prospect Hosp., 68 NY2d 320, 324; Fileccia v Massapequa Gen. Hosp., 63[*596] NY2d 639; Vogel v Palmieri, 221 AD2d 522; Muscatello v City of New York, 215 AD2d 463; Jederlinic v Arya, 209 AD2d 586; Toledo v Ordway, 208 AD2d 518; Dachille v Good Samaritan Hosp., 207 AD2d 373). Accordingly the complaint is dismissed insofar as asserted against the appellants. Rosenblatt, J. P., Miller, Thompson and Joy, JJ., concur.