Inherited polymorphisms in hyaluronan synthase 1 predict risk of systemic B-cell malignancies but not of breast cancer. PLoS One. 2014;9:e100691. [PMID: 24950197 PMCID: PMC4065063 DOI: 10.1371/journal.pone.0100691]

The epidemiology of Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a rare subtype of non-Hodgkin lymphoma characterized by the presence of lymphoplasmacytic lymphoma (LPL) in the bone marrow accompanied by a monoclonal immunoglobulin type M (IgM) in the serum. WM was first described only 80 years ago and became reportable in the US as a malignancy in 1988. Very little systematic research was conducted prior to 2000 to characterize incidence, clinical characteristics, risk factors or diagnostic and prognostic criteria, and there were essentially no WM-specific clinical interventional trials. Since the inaugural meeting of the International Workshop in Waldenström's Macroglobulinemia (IWWM) in 2000, WM has become the focus of a steadily increasing and productive body of research, engaging a growing number of investigators throughout the world. This introductory overview provides summary of the current understanding of the epidemiology of WM/LPL as a backdrop for a series of consensus panel recommendations arising from research presented at the 11th IWWM.

Exome sequencing reveals recurrent germ line variants in patients with familial Waldenström macroglobulinemia

Familial aggregation of Waldenström macroglobulinemia (WM) cases, and the clustering of B-cell lymphoproliferative disorders among first-degree relatives of WM patients, has been reported. Nevertheless, the possible contribution of inherited susceptibility to familial WM remains unrevealed. We performed whole exome sequencing on germ line DNA obtained from 4 family members in which coinheritance for WM was documented in 3 of them, and screened additional independent 246 cases by using gene-specific mutation sequencing. Among the shared germ line variants, LAPTM5(c403t) and HCLS1(g496a) were the most recurrent, being present in 3/3 affected members of the index family, detected in 8% of the unrelated familial cases, and present in 0.5% of the nonfamilial cases and in <0.05 of a control population. LAPTM5 and HCLS1 appeared as relevant WM candidate genes that characterized familial WM individuals and were also functionally relevant to the tumor clone. These findings highlight potentially novel contributors for the genetic predisposition to familial WM and indicate that LAPTM5(c403t) and HCLS1(g496a) may represent predisposition alleles in patients with familial WM.

Biology of hyaluronan: Insights from genetic disorders of hyaluronan metabolism

Hyaluronan is a rapidly turned over component of the vertebrate extracellular matrix. Its levels are determined, in part, by the hyaluronan synthases, HAS1, HAS2, and HAS3, and three hyaluronidases, HYAL1, HYAL2 and HYAL3. Hyaluronan binding proteins also regulate hyaluronan levels although their involvement is less well understood. To date, two genetic disorders of hyaluronan metabolism have been reported in humans: HYAL1 deficiency (Mucopolysaccharidosis IX) in four individuals with joint pathology as the predominant phenotypic finding and HAS2 deficiency in a single person having cardiac pathology. However, inherited disorders and induced mutations affecting hyaluronan metabolism have been characterized in other species. Overproduction of hyaluronan by HAS2 results in skin folding and thickening in shar-pei dogs and the naked mole rat, whereas a complete deficiency of HAS2 causes embryonic lethality in mice due to cardiac defects. Deficiencies of murine HAS1 and HAS3 result in a predisposition to seizures. Like humans, mice with HYAL1 deficiency exhibit joint pathology. Mice lacking HYAL2 have variably penetrant developmental defects, including skeletal and cardiac anomalies. Thus, based on mutant animal models, a partial deficiency of HAS2 or HYAL2 might be compatible with survival in humans, while complete deficiencies of HAS1, HAS3, and HYAL3 may yet be recognized.