What is the odds of passing tetroligy of fallot to a child? and what is the odds of passing tetroligy of fallot to a second child?

Tetralogy of Fallot: If you do not have one of the genetically associated mutations documented in yourself or your family which have their own predictive outcomes then the spontaneous incidence of Tetralogy of Fallot is 1 in a 1000 for male offspring and 1 in 2000 for female offspring

Genetic factors: Depends on which parent was affected. In general, a mother with congenital heart disease (CHD) will have ~5% chance of transmitting CHD to a child--not necessarily TOF though. The risk of TOF will also be significantly higher than the population baseline. If there is some other underlying genetic condition (e.g., DiGeorge syndrome), the risk may be significantly higher though.