A mother who is a full-time carer for her disabled son has won High Court orders directing the Minister for Justice to reconsider a refusal of visas for her other two children to join her here from an African country.

There were "grave deficiencies" in the Minister's decision refusing appeals by the woman over the rejection of applications for two 'join family' visas for the two children, Mr Justice Max Barrett ruled.

The mother, a native of an African country, is an Irish citizen and her disabled son has Irish residency.

Another son, aged 20, and the woman's teenage daughter, live with their father in an African country but it is claimed the father is of such an age he finds caring for them difficult, the judge noted.

The mother sought judicial review after the Minister rejected her appeals against decisions of the Irish Embassy in the relevant African country in May 2017 refusing the visas.

In his judgment, Mr Justice Barrett said the grave deficiencies in the Minister's decision include a statement when addressing the alleged ailing health of the applicants' father, that "no medical documents have been provided".

That was wrong because a medical certificate had been provided, the judge said.

Another finding there were no "special" circumstances in this case, made in the context of the State's Non-EEA family reunification policy, was based on inadequate reasoning, the judge considered.

The test set out in the policy is "exceptional" circumstances and it was unclear just what form of test was applied in this case, the judge said.

The son who is resident here is so disabled and unwell his mother cannot work outside the home so as to bring herself above the financial threshold identified in the family reunification policy, he noted.

A medical doctor/registrar at a "renowned health service provider" had provided a letter on headed paper stating the disabled son would "benefit hugely" from reunification with his siblings but the decision maker had said there was "no clear link" between that doctor and the son, the judge said.

The court did not know what the decision maker meant by that, he said.

If a decision maker considered a letter was "phoney" or that a particular doctor is behaving unprofessionally, there are ways of addressing that but no such circumstances was alleged to be present here, he said.

The disregard of that medical evidence for the reasons stated involved acting wrongly and unreasonably, he held.

Those and other administrative law deficiencies justified the Minister's decision being quashed and the matter is being remitted for reconsideration, the judge ruled.