A Family Screening of CD19 Gene Mutation by Restriction Fragment Length
Background: CD19 molecule found on B lymphocyte surface forms CD19
complex together with CD21, CD81, CD225 in mature B cells and regulates
B lymphocyte activation with antigen stimulation. Mutation(s) in the
gene encoding the CD19 molecule affect CD19 protein expression and
primary immunodeficiency (PID) occurs. Some genetic method, especially
sanger and next generation sequencing and flow cytometric methods are
widely used in the diagnosis of PID. The RFLP method, which is faster
and cheaper than other mutation detection methods, is rarely used in the
diagnosis of PID. The study aimed to genetically identify CD19
deficiency, which is a PID, using the RFLP method. Methods: The study
was performed at Necmettin Erbakan University, Meram Medicine Faculty
Hospital, Pediatric Allergy and Immunology clinic. A total of 8 patients
and two healthy controls could be included in the study. A total of 8
patients and two healthy controls were included in the study, and the
relevant region genotypes in the CD19 gene were determined by performing
RCR-RFLP analysis. Results: CD19 deficiency was first described by us.
The index case, newborn baby and mother were also included in the study.
It was determined that the index case (P6) was homozygous mutant, the
newborn baby (P7) and mother (P8) had heterozygous genotype. Based on
this situation, one child (P1) was found to be homozygous mutant, mother
(P2), father (P3) and other children (P4 and P5) had heterozygous
genotype in the family, which was determined to be related to the first
case. Conclusion: Rapid genetic diagnosis in patients suspected of
having a known case of PID insufficiency as a result of clinical and
laboratory findings carries a vital risk in terms of treatment options
to be offered to patients. Although PCR-RFLP, which is a cheap, safe and
fast method, is used to detect known mutations, the use of PID is rare.
In our study, it has been shown that it is a method that can be used in
the diagnosis of PID by determining genotypes using PCR-RFLP, and
especially in terms of rapid genetic testing of family screenings.