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The associations between the functional polymorphism in thrombospondins (THBSs) and lumbar-disc herniation (LDH), a common muscoskeletal disease are discussed. THBS2 is shown to highly affect alternative splicing and the binding of matrix metalloproteinases (MMPs) in the Japanese populations.

COL11A1, type XI collagen genes is identified as a gene for lumbar disc herniation (LDH) disease. It was observed that COL11A1 was highly expressed in intervertebral disc (IVD) but its expression was decreased in the IVD of patients with LDH.

Benign adult familial myoclonic epilepsy (BAFME), an autosomal dominant idiopathic epileptic syndrome recently recognized in Japanese families, is discussed relative to its localization to chromosome 8q23.3-q24.1. The gene locus was assigned by linkage analysis in a large Japanese kindred.

Research has determined a genetic locus for the autosomal recessive disorder gelatinous drop-like corneal dystrophy (GDLD), which causes amyloid deposits that impair vision. After linkage analyses were performed on affected Japanese subjects, homozygosity mapping placed the disease locus on the chromosome 1 short arm. Increased accuracy was obtained through haplotype analysis.

Congenital microcoria (MCOR) is a rare autosomal-dominant disorder characterized by inability of the iris to dilate owing to absence of dilator pupillae muscle. So far, a dozen MCOR-affected families have been reported worldwide. By using whole-genome oligonucleotide array CGH, we have identified deletions at 13q32.1 segregating with MCOR in six families originating from France, Japan, and Mexico. Breakpoint sequence analyses showed nonrecurrent deletions in 5/6 families. The deletions varied from 35 kbp to 80 kbp in size, but invariably encompassed or interrupted only two genes: TGDS encoding the TDP-glucose 4,6-dehydratase and GPR180 encoding the G protein-coupled receptor 180, also known as intimal thickness-related receptor (ITR). Unlike TGDS which has no known function in muscle cells, GPR180 is involved in the regulation of smooth muscle cell growth. The identification of a null GPR180 mutation segregating over two generations with iridocorneal angle dysgenesis, which can be regarded as a MCOR endophenotype, is consistent with the view that deletions of this gene, with or without the loss of elements regulating the expression of neighboring genes, are the cause of MCOR. [ABSTRACT FROM AUTHOR]

Lumbar disc herniation (LDH), degeneration and herniation of the nucleus pulposus of the intervertebral disc (IVD) of the lumbar spine, is one of the most common musculoskeletal diseases. Its etiology and pathogenesis, however, remain unclear. Type XI collagen is important for cartilage collagen formation and for organization of the extracellular matrix. We identified an association between one of the type XI collagen genes, COL11A1, and LDH in Japanese populations. COL11A1, which encodes the a1 chain of type XI collagen, was highly expressed in IVD, but its expression was decreased in the IVD of patients with LDH. The expression level was inversely correlated with the severity of disc degeneration. A single-nucleotide polymorphism (c.4603C→T [rs1676486]) had the most significant association with LDH (P = 3.3 x 10-6), and the transcript containing the disease-associated allele was decreased because of its decreased stability. These observations indicate that type XI collagen is critical for IVD metabolism and that its decrease is related to LDH. [ABSTRACT FROM AUTHOR]

Many disorders are associated with altered serum protein concentrations, including malnutrition, cancer, and cardiovascular, kidney, and inflammatory diseases. Although these protein concentrations are highly heritable, relatively little is known about their underlying genetic determinants. Through transethnic meta-analysis of European-ancestry and Japanese genome-wide association studies, we identified six loci at genome-wide significance (p < 5 × 10(-8)) for serum albumin (HPN-SCN1B, GCKR-FNDC4, SERPINF2-WDR81, TNFRSF11A-ZCCHC2, FRMD5-WDR76, and RPS11-FCGRT, in up to 53,190 European-ancestry and 9,380 Japanese individuals) and three loci for total protein (TNFRS13B, 6q21.3, and ELL2, in up to 25,539 European-ancestry and 10,168 Japanese individuals). We observed little evidence of heterogeneity in allelic effects at these loci between groups of European and Japanese ancestry but obtained substantial improvements in the resolution of fine mapping of potential causal variants by leveraging transethnic differences in the distribution of linkage disequilibrium. We demonstrated a functional role for the most strongly associated serum albumin locus, HPN, for which Hpn knockout mice manifest low plasma albumin concentrations. Other loci associated with serum albumin harbor genes related to ribosome function, protein translation, and proteasomal degradation, whereas those associated with serum total protein include genes related to immune function. Our results highlight the advantages of transethnic meta-analysis for the discovery and fine mapping of complex trait loci and have provided initial insights into the underlying genetic architecture of serum protein concentrations and their association with human disease., (Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)