That's not true.
If there is a god, those are His most special of all children.
And if there's not a god, well, given to the right right parents, those special kids can light a fire of goodness in the souls of their parents that touches the lives of... and inspire's... everyone they meet.
Quit being so f'ing negative.... and tune in to whatever makes this world spin.
Case closed.
What faith closes, knowledge opens.
If there was a Good, there wouldn't be any birth defects.
What "good" may come of it does not justify the experience, if you have that much control over the genesis of all things. Because experiences are born of their own kind...violence begets violence, ignorance begets ignorance...etc.
You observe that something good might come of it for the parents? But why are the parents lacking good in the first place? What is the genesis of the bad?
The god of this world, what concieves of children and causes them to be born, is more like an algorithm. It is tasked with the design of duality .
Duality is the alternating and simultaneous experience of opposites, symbolized by the "tree of the knowledge of good and evil".
In duality there appear polar extremes for every concept conceivable in imagination. Between the extremes there is every shade of grey imaginable.
In duality, for example, children are not all bad, but not all good either. Some will be very good, some very bad. Not all healthy, not all unhealthy. Some very healthy, some very sick...ad nauseum.
The motive/objective/purpose of duality is to manufacture special status for every "individual". Duality begets diversity. Diversity begets special status. This is the genesis of "special" children.
But at what cost? At the cost of perfection, or what ill call Only-The-Good.
Duality technically offers MORE than Only-The-Good. So it is TEMPTING. You need to become weary of duality to be ready to overcome it, and return to Only-The-Good.
Only the weary will call the designer of duality 'the devil". Those still tempted by duality will call the designer 'God", and worship it.
In Only-The-Good, every genesis is perfect, free from opposing alternatives. Every genesis is Only-The-Good, nothing more, nothing less. How can you add or subtract from perfection?
This is called Oneness, symbolized by the 'tree of Life". Note well, it is Only-Life, not tree of life and death (duality). It is Life and Only Life, Truth and nothing but the Truth, Good and only the Good.
One must choose which 'tree' to abide by (be loyal to). To be loyal to one is to be disloyal to the other. To be for one is to be against the other. These are mutually exclusive, incompatible, irreconcilable differences that are worlds apart.