Gene mutation profiles and prognostic implications in Korean patients with T-lymphoblastic leukemia

Abstract

Genetic alterations implicated in the leukemogenesis of T cell acute lymphoblastic leukemia (T-ALL) have been identified in recent years. In this study, we investigated gene mutation profiles and prognostic implications in a series of Korean T-ALL patients. The study patients were 29 Korean patients with T-ALL; 13 adults (45%) and 16 children (55%; male-to-female ratio, 25:4). Clinical, hematologic, and cytogenetic findings were reviewed. We performed mutation analyses for NOTCH1, FBXW7, PHF6, and IL7R genes and survival analyses according to the mutational status. Gene mutations were identified in 66% of the patients in our series (19/29). Eighteen patients (62%) had NOTCH1/FBXW7 mutations. Sixteen patients (55%) had NOTCH1 mutations including nine novel mutations, and eight patients (28%) had known FBXW7 mutations. Eight patients (28%; six males and two females) had PHF6 mutations including four novel mutations. Three patients (10%) had IL7R mutations, which were all novel in-frame insertion or deletion-insertions. The gene mutation profile combined with cytogenetics and FISH study for the p16 gene detected genetic aberrations in 90% of patients (26/29). There was no significant difference in the frequency of gene mutations between the pediatric and adult patients with T-ALL. Survival analyses suggested a favorable prognostic implication of NOTCH1 mutations in adult T-ALL. Gene mutation studies for NOTCH1, FBXW7, PHF6, and IL7R could detect genetic alterations in a majority of Korean T-ALL patients with novel mutations. We observed similar mutation profiles between adult and pediatric T-ALL, and a favorable prognostic implication of NOTCH1 mutations in adult T-ALL.