This finding indicates that EBV is not the cause for the NK cell activation and excessive proliferation seen in NKCE and LG and distinguishes these diseases from malignant diseases they can mimic such as extranodal NK/T-cell lymphoma, nasal type. In isolated reports, LG has occurred in individuals with Helicobacter pylori infection of the stomach or a history of stomach cancer, while NKCE has been reported to occur in patients with gluten sensitivity or circulating anti-gliadin antibodies. Both of the latter conditions are associated with the development of GI tract lymphomas. However, the relationship of any of these findings to the etiology of LB and NKCE is unclear. Histology
Biopsies of NKCE tissues reveal atypical medium to large lymphocytes identified by immunohistochemistry to be NK cells that are multiplying at a moderately rapid rate and that lack evidence of being infected by the Epstein-Barr virus. These cells are located primarily in the lamina propria, i.e. loose connective tissue lying just below the epithelium lining the GI tract. There is generally little invasion of these cells into the epithelium, submucosa, or glands of the GI tract, and the lesions almost always show a complete absence of vascular injury due to invasion by these cells. The lesions in LG closely resemble those of NKCE.
Disruptions in this pathway, caused by FLNB mutations, result in the bone and cartilage abnormalities associated with boomerang dysplasia.Chondrocytes, which also have a role in bone development, are susceptible to these disruptions and either fail to undergo ossification, or ossify incorrectly.FLNB mutations are involved in a spectrum of lethal bone dysplasias. One such disorder, atelosteogenesis type I, is very similar to boomerang dysplasia, and several symptoms of both often overlap. Genetics
Early journal reports of boomerang dysplasia suggested X-linked recessive inheritance, based on observation and family history. It was later discovered, however, that the disorder is actually caused by a sporadic genetic mutation fitting an autosomal dominant genetic profile.Autosomal dominant inheritance indicates that the defective gene responsible for a disorder is located on an autosome, and only one copy of the gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.Boomerang dysplasia, although an autosomal dominant disorder, is not inherited because those afflicted do not live beyond infancy. They cannot pass the gene to the next generation. Diagnosis
Treatment
See also
Larsen syndrome

References


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