The Polymorphisms In LNK Gene Correlated To The Clinical Type Of Myeloproliferative Disorders

LNK (lymphocyte adaptor protein) is an adapter protein negatively regulating JAK/STAT cell signaling pathway. In this study, we observed the effects of variations in LNK gene on the clinical type of myeloproliferative disorders (MPD).

A total of 285 MPD cases were recruited, including essential thrombocythemia (ET) 154 cases, polycythemia vera (PV) 76 cases, idiopathic myelofibrosis (IMF) 19 cases, and chronic myeloid leukemia (CML) 36 cases. Ninety-three healthy individuals were used as normal controls. V617F mutation in JAK2 was searched by allele-specific primers method, RT-PCR was used for the detection of BCR/ABL1 fusion gene, and mutations and variations in exons and their flanking sequences of LNK gene were examined by PCR-sequencing. Count data were analyzed by χ2 or Fisher exact test.

The genotypes of 4 SNPs (rs3184504, rs111340708, rs78894077and rs7973120) could be identified. Missense mutations of A300V, V402M, and R415H in LNK were found in 8 patients, of whom 3 ET patients had homozygous A300V mutation combined with JAK2V617F mutation. The genotypes and allele types of the 3 SNPs (rs3184504, rs111340708 and rs78894077) correlated to the clinical type of MPD. For rs3184504, the allele frequencies of C/T were 0.5/0.5 in normal controls, 0.117/0.883 in ET, 0.132/0.868 in PV, 0.211/0.789 in IMF, and 0.944/0.056 in CML; T allele (p.262Trp) was significantly higher in ET, IMF and PV (P<0.01), and C allele (p.262Arg) was significantly higher in CML (P<0.01), as compared with the controls. For rs78894077, the allele frequencies of C/T were 0.097/0.903 in normal controls, 0.045/0.955 in ET, 0.086/0.914 in PV, 0.053/0.947 in IMF, and 0.167/0.833 in CML; T allele (p.242Ser) was higher in ET (P<0.05) than in normal controls. For rs111340708 which has 2 alleles of repeated sequences (TGGGG x5/TGGGG x4), the allele frequencies of TGGGG x5/TGGGG x4 were 0.462/0.538 in normal controls, 0.719/0.281 in ET, 0.533/0.467 in PV, 0.789/0.211 in IMF, and 0.639/0.361 in CML; TGGGG x4 allele was significantly lower in ET, IMF and CML than in normal controls (P<0.01). However, the allele frequencies of rs3184504 and rs111340708 were unrelated to the presence of JAK2V617F mutation and BCR/ABL1 fusion gene in MPD patients.

The polymorphisms of SNPs in LNK gene correlated to the clinical type of MPD.

No relevant conflicts of interest to declare.