兒子有G6PD [ 酵素缺乏証 ]，是(父)還是(母)會有此証的呢？

It will be the mother. Genetics is complicated so i will explain it step by step.

1. Males are XY and females are XX in terms of their genetic material (known as chromosome).
2. The sperm (male) carries either X or Y, and all eggs (female) carry only X.
3. So it is the male who determines whether the baby is male or female (i.e. X sperm + X egg = baby girl, X sperm + Y egg = baby boy).
4. The G6PD gene is X-linked, meaning it is attached to X. A female will need two G6PD genes to get the disease, but male will only need one - therefore G6PD occurs in males more frequently than females. Healthy carriers of the G6PD genes are always female.
5. Males can only be the sufferer but not carrier. So in your case if your husband doesnt have G6PD, then it is almost certain that the gene came from you.

The same theory applies to colour blindness, which usually appear in male.

Sorry this is the best i can do, hope it helps.

假如G6PD是由父方遺傳的，父親亦必定患有G6PD，否則一定由母方遺傳。
不過，假如是由母方遺傳的話，母親亦不一定患有G6PD。