Identification of clonal immunoglobulin λ light-chain gene rearrangements in AL amyloidosis using next-generation sequencing

•Next-generation sequencing of bone marrow cells can identify clonal immunoglobulin λ light-chain gene rearrangements in most patients with light-chain (AL) amyloidosis.•The clones in AL amyloidosis are significantly smaller than those in multiple myeloma but comparable to those in monoclonal gammopathy of undetermined significance.•The difference in involved and uninvolved free light chains (dFLC) is not correlated with the clonal size of bone marrow plasma cells.