Relationship Between Deletion Size and Cellular Immunodeficiency in Chromosome 22q112 Deletion Di George Syndrome
Project no. 23140 · Status: Kapanmış (Yayın bekleniyor) · 2022
Summary
<p>22q11.2 deletion syndrome (22q11.2DS, Di George syndrome, velocardiofacial syndrome) is a syndrome that can present with highly variable physical, immunological and neuropsychiatric findings, resulting from hemizygous microdeletions in the chromosome 22q11.2 region. Its incidence is 1 in 4000 live births. De novo deletions are seen in approximately 90% of cases, while autosomal dominant inheritance is seen in 10%. The deletion mechanism is non-allelic homologous recombination of low copy repeats (LCR). Low copy repeats (LCR) are also defined as segmental duplications. Molecular diagnosis of deletions in the chromosome 22q11.2 region can be made by Fluorescence In Situ Hybridization (FISH) and multiplex ligation probe amplification (MLPA) methods.</p><p><br></p><p>In 22q11.2DS, T cell lymphopenia due to thymic hypoplasia is the major immunological finding. While T cell lymphopenia observed due to thymic hypoplasia shows dynamic changes in most affected patients and improves with age, in a rare group of patients, there is no or very little improvement in T lymphocyte count and cellular immune response. In cases where cellular immune deficiency improves with age, the frequency of infection, antibiotic use and hospitalizations decrease, while their quality of life increases significantly. In the group where CD3 lymphopenia does not improve, problems such as the need for frequent infection, the need to use many antibiotics or hospitalization, the necessity of regular intravenous immunoglobulin replacement therapy, and absenteeism from school continue, and mortality and morbidity rates are significantly higher than in the group where CD3 lymphopenia improves.</p><p><br></p><p>This study aimed to investigate the relationship between deletion size and type and T cell lymphopenia in cases followed up with the diagnosis of 22q11.2 DS with and without improvement in CD3 lymphopenia.</p>