International experts study SCID variants in the Irish Family

The Irish Traveller population has a higher than average prevalence of severe combined immunodeficiency (SCID), similar to the Navajo Nation and the Amish and Mennonite communities, and international SCID experts are collaborating to identify SCID variants and improve treatment.

Dr. Jolan Walter, division chief of the University of South Florida and Johns Hopkins All Children’s Pediatric Allergy and Immunology Programs, along with Dr. Stanton Goldman, principal investigator for the Children’s Oncology Group of Medical City Dallas and chief medical officer for Medical City Children’s Hospital, presented “SCID Variants and the Irish Family” during the 2021 SCID Compass Summit.

Who are the Irish Travellers? They are a tight-knit ethnic minority of Irish descent that number about 70,000 globally, with the majority living in pockets throughout Ireland and about 25,000 living in the U.S., the United Kingdom, and Canada. The Irish Travellers, known in the U.S. as the Irish Family, generally marry within their community.

Among the Irish Traveller population in the country of Ireland, the infant mortality rate is three and half times that of the general population. There are between 650 and 850 Irish Traveller babies born each year in Ireland and 10 percent do not live past their second birthday. The main causes of mortality are accidents, congenital malformations, and inherited metabolic disorders.

Over 104 genetic disorders exist in the Irish Traveller community in Ireland, a very high number of genetic defects for such a small population, said Dr. Walter. Among the genetic diseases are variants of SCID, including recombination-activating gene (RAG), adenosine deaminase deficiency (ADA), and Omenn’s Syndrome. 

“What we were trying to determine is how much of these genetically related disorders are affecting the health of this population. In the U.S., not much is known, but we think it’s probably not as severe as in Ireland,” said Dr. Walter.

Drs. Walter and Goldman work closely with SCID experts in Ireland and the United Kingdom to share data and studies concerning the Irish Travellers. 

“Through this international collaboration, we think that these genetic defects were probably in the gene pool for decades and hundreds of years and I must mention that in talking to the families, there is still a lot of migration happening from Ireland and people going back to Ireland and marrying people in Ireland, so there is a possibility that there is a constant influx of genetic enhancement through these processes,” said Dr. Walter.

Listen to “SCID Variants and the Irish Family.”