Abstract
Severe Combined Immunodeficiencies (SCID) are a group of childhood diseases with a very serious prognosis. They occur with a frequency of 1 in 40-100,000 children under one year of age.
Early diagnosis is the main prognostic factor for the success of therapy. If left untreated, it is fatal.
Causal treatment is haematopoietic stem cell transplan-tation. Since January 2022, a pilot newborns screening project for SCID has been running in the Czech Republic.
This article presents case reports of two patients with SCID diagnosed in our department in 2021. The first is an 8-month-old boy hospitalized for bilateral pneumonia with respiratory insufficiency.
Pneumocystis jiroveci was iden-tified as the causative agent. The condition was preceded by a period of failure to thrive and laboratory findings of lymphopenia.
Additional immunological examination revealed severe hypogammaglobulinemia with impaired specific antibody production and T lymphopenia with low activation tests. Genetic testing revealed an X-linked form of SCID (defect in the IL2 receptor gene; c.925-13>G).
The boy was subsequently successfully transplanted. Second case report of a 2-month-old girl hospitalized for severe infection with concurrent SARS-CoV-2 positivity with fatal outcome.
Post mortem findings were generalized CMV infection, severe thymic dysplasia with absence of T lymphocytes. The cause was determined to be an autosomal recessive form of SCID with mutation of the IL7 receptor gene (biallelic defect NM_002185.5: c.132C >A, p.
Ser44Arg, a c.514delG, p. Glu172Lysfs*10).