Newborn Screening for SCID. Experience in Spain (Catalonia)

Area of Science:

• Immunology
• Genetics
• Public Health

Background:

• Severe combined immunodeficiency (SCID) is a rare genetic disorder affecting T-cell development.
• Early detection and treatment of SCID are crucial for survival.
• Catalonia, Spain, initiated universal newborn screening for SCID in January 2017.

Purpose of the Study:

• To present the results of the first three and a half years of SCID newborn screening in Catalonia.
• To determine the incidence of SCID and significant T-cell lymphopenia in the screened population.
• To provide evidence supporting the inclusion of SCID in national newborn screening programs.

Main Methods:

• Screening of all newborns in Catalonia between January 2017 and June 2020.
• TREC (T-cell receptor excision circle) quantification in dried blood spots (DBS) using the Enlite Neonatal TREC-kit.
• Analysis of screening data for SCID diagnosis and identification of T-cell lymphopenia.

Main Results:

• A total of 222,857 newborns were screened.
• Three cases of SCID were diagnosed, yielding an incidence of 1 in 74,187 newborns.
• 17 patients with clinically significant T-cell lymphopenia (non-SCID) were identified (incidence of 1 in 13,109).

Conclusions:

• Newborn screening for SCID in Catalonia has successfully identified affected infants.
• The program also identified infants with other forms of T-cell lymphopenia, enabling timely intervention.
• These findings support the implementation of a national SCID newborn screening program in Spain to establish precise incidence rates and ensure early diagnosis.