Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two- to three-week-old mice homozygous for the recessive oc gene had negligible numbers of marrow cells but possessed no significant spleno- and hepatomegaly. They also maintained normal numbers of blood cells except for monocytes, which were significantly lower. Additionally, they had reduced numbers of total cells and resident macrophages in the peritoneum, as determined by cell counts in the peritoneal lavage fluid. The frequency of spleen colony-forming units (CFU-S) in the spleens of oc/oc mice was the same as that in the spleens of normal littermate control mice. These oc/oc CFU-S showed essentially similar differentiation patterns as CFU-S of control mice. Also, a few CFU-S could be detected in livers of oc/oc mice. On the other hand, the frequency of cells that formed macrophage colonies in a four-day liquid-culture system in the presence of colony-stimulating activity was significantly reduced in oc/oc mice and abnormalities were observed in the formation of the adherent (stromal) layers by oc/oc spleen cells in liquid cultures. Numbers of fibroblastoid cell colonies in these layers were reduced and, moreover, cultures demonstrated a marked decrease in the number of macrophages both within and outside the fibroblastoid cell colonies. Transplants of spleen and thymus cells of oc/oc mice into lethally irradiated +/? recipients induced oc/oc-like lesions. They included peritoneal macrophage deficiency, marrow deficiency, as well as hepatosplenomegaly. This suggests a hemopoietic stem cell and not microenvironmental defect in this particular type of osteopetrosis. The murine mutant characterized in this study may be useful in studies of cellular interactions during blood and bone formation and in studies of the mononuclear phagocyte system.
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PMID:Congenital murine osteopetrosis inherited with osteosclerotic (oc) gene: hematological characterization. 375 33

Optimal lysosome function requires maintenance of an acidic pH maintained by proton pumps in combination with a counterion transporter such as the Cl-/H+ exchanger, CLCN7 (ClC-7), encoded by CLCN7. The role of ClC-7 in maintaining lysosomal pH has been controversial. In this paper, we performed clinical and genetic evaluations of two children of different ethnicities. Both children had delayed myelination and development, organomegaly, and hypopigmentation, but neither had osteopetrosis. Whole-exome and -genome sequencing revealed a de novo c.2144A>G variant in CLCN7 in both affected children. This p.Tyr715Cys variant, located in the C-terminal domain of ClC-7, resulted in increased outward currents when it was heterologously expressed in Xenopus oocytes. Fibroblasts from probands displayed a lysosomal pH approximately 0.2 units lower than that of control cells, and treatment with chloroquine normalized the pH. Primary fibroblasts from both probands also exhibited markedly enlarged intracellular vacuoles; this finding was recapitulated by the overexpression of human p.Tyr715Cys CLCN7 in control fibroblasts, reflecting the dominant, gain-of-function nature of the variant. A mouse harboring the knock-in Clcn7 variant exhibited hypopigmentation, hepatomegaly resulting from abnormal storage, and enlarged vacuoles in cultured fibroblasts. Our results show that p.Tyr715Cys is a gain-of-function CLCN7 variant associated with developmental delay, organomegaly, and hypopigmentation resulting from lysosomal hyperacidity, abnormal storage, and enlarged intracellular vacuoles. Our data supports the hypothesis that the ClC-7 antiporter plays a critical role in maintaining lysosomal pH.
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PMID:Lysosomal Storage and Albinism Due to Effects of a De Novo CLCN7 Variant on Lysosomal Acidification. 3115 84