XLA Screening

X-linked agammaglobulinemia (XLA) is a genetic disorder where patients are not able to produce enough functional B-cells. Newborns with XLA suffer from a reduced immune response to infections, and the condition may be life-threatening. XLA is an X-linked recessive disease which almost exclusively affects young boys.

KRECs are produced during the process of recombination of B-cells. Lack of KRECs can indicate low or no production of functional B-cells. Newborns identified with low or no KRECs may suffer from XLA and should be referred for confirmatory testing.

Newborn screening for XLA can detect the lack of KRECs within a few days after birth, facilitating an earlier diagnosis for patients with XLA and earlier initiation of treatment.

1. Borte, S., von Döbeln, U., Fasth, A., Wang, N., Janzi, M., Winiarski, J., Sack, U., Pan-Hammarström, Q., Borte, M., & Hammarström, L. (2012). Neonatal screening for severe primary immunodeficiency diseases using high-throughput triplex real-time PCR. Blood, 119(11), 2552–2555. https://doi.org/10.1182/blood-2011-08-371021