Father and son are carriers of two different types of human inborn errors of immunity: a case report

Chronic granulomatous disease (CGD) is an inborn error of immunity (IEI) characterized by recurrent bacterial and fungal infections of skin, airways, liver, brain and bones with the estimated prevalence of 1 in 250,000 live births. CGD can inherited either in an X-linked (allelic variants in the CYBB gene) or autosomal recessive mode (allelic variants in the CYBA, NCF1, NCF2, NCF4, and CYBC1 genes). Wiskott-Aldrich syndrome is an X-linked disorder with an estimated incidence of 1 in 100 000 live male births caused by variants in the WAS gene, characterized by microthrombocytopenia, eczema, recurrent infections, increased risk for autoimmune disease and malignancy. In this case report, we present our experience about two cases of blood relatives diagnosed with different types of human inborn errors of immunity. Genetic analysis of CYBB gene in 2007 was performed by Sanger sequencing and of WAS gene in 2022 by next generation amplicon sequencing. All subjects consented to the study. The first case was a 15-year-old male (1992 y.o.b., proband) who was diagnosed as X-linked CGD patient in 2007 due to his clinical history and hemizygote allelic variant in the CYBB gene (NM_000397.4: c.484–1G>T, COSV101059810). The second case was a 2-month-old boy (biological son of proband) who was hospitalized in 2022 due to microthrombocytopenia, low platelet volume, cytomegalovirus infection, mild anemia. Genetic analysis revealed in the DNA sample of the second case the hemizygote allelic variant in the WAS gene (NM_000377.3: c.777 +3_777+6del GAGT). Genetic testing didn’t reveal such variant in the DNA sample of the proband's wife, that's why this variant was classified as “de novo”. Inborn errors of immunity (IEI) present clinically as increased susceptibility to infections, autoimmunity, autoinflammatory diseases, allergy, bone marrow failure, and/or malignancy. There are now a total of 485 IEI, which are segregating to 10 groups of disorders into overlapping phenotypes. Despite the fact that IEI are rare diseases, we have shown that even in one family two different types of disorders can occur. In our case the second IEI was occur due to spontaneously alterations during the process of DNA replication during cell division.