The Supreme Court has agreed to hear an appeal by the State over whether the word “child” in the International Protection Act can, for family reunification purposes, means more than simply biological and adopted children.

It arises from a High Court decision in the case of a man – Mr X – who was granted family reunification with a 14-year-old boy and 13-year-old girl even though he did not establish genetic parentage of them.

In a judgment last May, Mr Justice Max Barrett said the term “child” is not defined in section 56.9 of the 2015 Act. Assuming these two children are the biological children of another man, although Mr X regards them as his, each of them can still properly be described as a child of Mr X, he said.

He added that there is a “wide diversity” of familial structures and the relationship of father/child is not confined by the 2015 Act to a biological father. It is “not unknown” for a child to grow up addressing and thinking of a man who is not their biological father as “Dad”.

A “cookie cutter” definition of children, as embracing only biological children, “would doubtless be easier for the State to police”, not least given the availability of DNA testing, “but it is not what the Act provides”, perhaps because of an understanding that, in a diverse society, defining who is a child of someone “is not always straightforward”.

The Supreme Court will now hear an appeal of that decision by the State.