title: A case of autosomal dominant osteopetrosis type II with a novel TCIRG1 gene mutation.
abstract: Osteopetrosis is a rare genetic disorder characterized by increased bone mineral density (BMD) due to osteoclast failure. T-cell immune regulator 1 (TCIRG1) plays crucial roles on osteoclast function, and its mutation causes autosomal recessive osteopetorosis. However, mutations in TCIRG1 have never been identified in autosomal dominant osteopetrosis (ADO). A 3-year-old boy was first presented to the clinic because of spontaneous radius and femur fractures. He has optic atrophy. The areal BMD at the lumbar spine was 1274 g/cm2 (233% of normal). Laboratory tests revealed no remarkable abnormal findings, including anemia, except for extremely elevated serum tartrate-resistant acid phosphatase-5b (14,600 mU/dL). Radiographically, the skull base, pelvis, and vertebrae showed a focal sclerosis. Genetic analysis revealed a novel de novo heterozygous missense mutation (His242Arg). Taken together with the mutation, his mild clinical features were diagnosed as ADO. This case implies that TCIRG1 could become a genetic candidate for ADO in addition to malignant forms such as ARO.
authors: Department of Pediatrics, Osaka Koseinenkin Hospital, Osaka, Japan.
authors: Keiko
authors: K
authors: Wada
authors: Daisuke
authors: D
authors: Harada
authors: Toshimi
authors: T
authors: Michigami
authors: Kanako
authors: K
authors: Tachikawa
authors: Yukako
authors: Y
authors: Nakano
authors: Hiroko
authors: H
authors: Kashiwagi
authors: Sumie
authors: S
authors: Yamashita
authors: Tetsuya
authors: T
authors: Sano
authors: Yoshiki
authors: Y
authors: Seino
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D002675:Child, Preschool; D005799:Genes, Dominant; D006801:Humans; D008297:Male; D010022:Osteopetrosis / Q000151:congenital* / Q000000981:diagnostic imaging / Q000235:genetics; D011859:Radiography; D012272:Ribs / Q000000981:diagnostic imaging; D013131:Spine / Q000000981:diagnostic imaging; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics*
chemical_list: C472421:TCIRG1 protein, human; D025262:Vacuolar Proton-Translocating ATPases