Identification of novel RASGRP2 mutations in patients with platelet dysfunction

Area of Science:

• Hematology
• Genetics
• Molecular Biology

Background:

• Inherited platelet function disorders (IPFDs) are rare genetic conditions affecting platelet function.
• Bleeding disorder platelet-type 18 (BDPLT18) is an autosomal recessive disorder caused by RASGRP2 mutations.
• The RASGRP2 gene encodes CalDAG-GEFI, crucial for platelet activation via αIIbβ3 integrin.

Purpose of the Study:

• To perform mutational analysis of the RASGRP2 gene in eleven unrelated patients with suspected BDPLT18.
• To identify novel and known mutations in RASGRP2 associated with BDPLT18.

Main Methods:

• Eleven unrelated patients with bleeding disorders were studied.
• Patients exhibited normal platelet receptor expression (CD41, CD61, CD42b) and impaired responses to common agonists.
• RASGRP2 gene mutations were screened using polymerase chain reaction (PCR) and Sanger sequencing.

Main Results:

• Seven mutations in the RASGRP2 gene were identified across the eleven patients.
• Four novel missense mutations (p.F497L, p.F501L, p.N505K, p.C515G) were discovered.
• Three known mutations (p.D441N, p.R494Afs*54, g.10410 G>T) were also found, predicted to alter CalDAG-GEFI protein function.

Conclusions:

• Identification of RASGRP2 mutations is key for diagnosing BDPLT18.
• Genetic findings help differentiate BDPLT18 from other platelet function disorders.
• Accurate diagnosis facilitates targeted therapeutics to prevent bleeding complications.