In designing insurance policies, individual companies may decide at their own discretion whether or not to cover congenital diseases, provided that such must be reflected in the premium rates. Further, a company not insuring against congenital diseases in a policy shall specifically list the names of uncovered congenital diseases in the brochures, proposals, and provisions. Otherwise, Insurance Act Article 54-1 will be exercised. In addition, in accordance with Insurance Act Article 51, paragraph 1, if the risk associated with the subject matter insured has already occurred or ceased to exist at the time an insurance contract is entered into, the contract shall be void, provided that this rule shall not apply when neither of the contracting parties is aware of the occurrence or cessation of existence. Hence, if neither of the parties is aware of the existence of the congenital disease, the insurance contract entered into is still valid. In accordance with Article 127 of the Insurance Act, if, at the time an insurance contract is entered into, the insured is already sick [including congenital diseases], the insurer is not obligated to pay the insured amount for the sickness, provided that it has proof that the insured or proposer was aware of such sickness before contract was entered into.