A new study suggests mutations in the gene DDX41 occur in families where hematologic malignancies are common.
Previous research showed that both germline and acquired DDX41 mutations occur in families with multiple cases of late-onset myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML).
The new study, published in Blood, has linked germline mutations in DDX41 to chronic myeloid leukemia and lymphomas as well.
“This is the first gene identified in families with lymphoma and represents a major breakthrough for the field,” said study author Hamish Scott, PhD, of the University of Adelaide in South Australia.
“Researchers are recognizing now that genetic predisposition to blood cancer is more common than previously thought, and our study shows the importance of taking a thorough family history at diagnosis.”
To conduct this study, Dr Scott and his colleagues screened 2 cohorts of families with a range of hematologic disorders (malignant and non-malignant). One cohort included 240 individuals from 93 families in Australia. The other included 246 individuals from 198 families in the US.
In all, 9 of the families (3%) had germline DDX41 mutations.
Three families carried the recurrent p.D140Gfs*2 mutation, which was linked to AML.
One family carried a germline mutation—p.R525H, c.1574G.A—that was previously described only as a somatic mutation at the time of progression to MDS or AML. In the current study, the mutation was again linked to MDS and AML.
Five families carried novel DDX41 mutations.
One of these mutations was a germline substitution—c.435-2_435-1delAGinsCA—that was linked to MDS in 1 family.
Two families had a missense start-loss substitution—c.3G.A, p.M1I—that was linked to MDS, AML, chronic myeloid leukemia, and non-Hodgkin lymphoma.
One family had a DDX41 missense variant—c.490C.T, p.R164W. This was linked to Hodgkin and non-Hodgkin lymphoma (including 3 cases of follicular lymphoma). There was a possible link to multiple myeloma as well, but the diagnosis could not be confirmed.
And 1 family had a missense mutation in the helicase domain—p.G530D—that was linked to AML.
“DDX41 is a new type of cancer predisposition gene, and we are still investigating its function,” Dr Scott noted.
“But it appears to have dual roles in regulating the correct expression of genes in the cell and also enabling the immune system to respond to threats such as bacteria and viruses, as well as the development of cancer cells. Immunotherapy is a promising approach for cancer treatment, and our research to understand the function of DDX41 will help design better therapies.”
