Linkage of epidermolysis bullosa simplex to keratin gene loci.

Epidermolysis bullosa simplex (EBS) is an autosomal dominant disorder characterised by intraepidermal blistering of the skin. Two families with Weber-Cockayne EBS have been analysed for linkage to keratin gene loci. In the first family, linkage was found to chromosome 17 markers flanking the keratin 14 gene (D17S74: Zmax = +2.45, theta = 0.10; COL1A1: Zmax = +0.97, theta = 0.00) and markers near the keratin 5 gene on chromosome 12 were excluded (D12S17: Z less than -2.0, theta = 0.08; COL2A1: Z less than -2.0, theta = 0.13). In contrast, the second family showed linkage to the region containing the keratin 5 gene (D12S17: Zmax = +1.37, theta = 0.08; COL2A1: Zmax = +0.33, theta = 0.15) and was not linked to the keratin 14 gene (D17S74: Z less than -2.0, theta = 0.14). The Weber-Cockayne form of EBS is genetically heterogeneous with linkage to different keratin gene loci.     

Linkage of a gene for dominant non-syndromic deafness to chromosome 19

Inherited hearing impairment can occur either in the presenceof other clinical features (syndromic hearing loss, SHL) orin isolation (non-syndromic hearing loss, NSHL). The latteris more common and is highly heterogeneous. To date, six NSHLloci have been mapped. We report the identification of a seventhlocus (DFNA4) on chromosome 19q13 and suggest DM kinase as apossible candidate gene.     

Antibodies to nuclear lamins in autoimmune liver disease

Antibodies to nuclear lamins were detected in sera of patients with autoimmune liver disease. In indirect immunofluorescence tests, these sera revealed staining of the nuclear periphery. Using isolated nuclei, nuclear matrices, nuclear lamina-pore complexes, and chromatographically purified lamins as antigen source, the nuclear lamins A, B, and C were identified as reactive antigens in immunoblotting experiments. The lamins were also identified by 2-D gel electrophoresis. Antibodies to nuclear lamins occurred in 12 of 16 cases of active lupoid hepatitis, but not in 35 patients with the disease in remission. However, only 3 of 37 sera of patients with primary biliary cirrhosis contained anti-lamin antibodies. Autoimmune liver disease sera reacted preferentially with lamins A/C and less frequently with lamin B or lamins A/B/C.     

Inhibition of extracellular signal-regulated kinase signaling to prevent cardiomyopathy caused by mutation in the gene encoding A-type lamins

Autosomal Emery–Dreifuss muscular dystrophy and relateddisorders with dilated cardiomyopathy and variable skeletalmuscle involvement are caused by mutations in LMNA, which encodesA-type nuclear lamins. How alterations in A-type lamins, intermediatefilament proteins of the nuclear envelope expressed in mostdifferentiated somatic cells, cause cardiomyopathy is only poorlyunderstood. We demonstrated previously abnormal activation ofthe extracellular signal-regulated kinase (ERK) branch of themitogen-activated protein kinase (MAPK) signaling cascade inhearts of Lmna H222P ‘knock in’ mice, a model ofautosomal Emery–Dreifuss muscular dystrophy. We thereforetreated Lmna^H222P/H222P mice that develop cardiomyopathy withPD98059, an inhibitor of ERK activation. Systemic treatmentof Lmna^H222P/H222P mice with PD98059 inhibited ERK phosphorylationand blocked the activation of downstream genes in heart. Italso blocked increased expression of RNAs encoding natriureticpeptide precursors and proteins involved in sarcomere organizationthat occurred in placebo-treated mice. Histological analysisand echocardiography demonstrated that treatment with PD98059delayed the development of left ventricular dilatation. PD98059-treatedLmna^H222P/H222P mice had normal cardiac ejection fractions assessedby echocardiography when placebo-treated mice had a 30% decrease.These results emphasize the role of ERK activation in the developmentof cardiomyopathy caused by LMNA mutations. They further provideproof of principle for ERK inhibition as a therapeutic optionto prevent or delay heart failure in humans with Emery–Dreifussmuscular dystrophy and related disorders caused by mutationsin LMNA.     

Autoantibodies to major and minor nuclear lamins are not restricted to autoimmune diseases.

Autoantibodies to lamins, the major polypeptide components of the nuclear lamina, have been reported in selected sera from patients with autoimmune diseases, including anti-lamin B in systemic lupus erythematosus (SLE) and anti-lamins AC in autoimmune chronic active hepatitis (CAH). We have studied the frequency, specificity, and isotypy of autoantibodies to major and minor lamins by immunoblotting on purified rat liver lamins in 190 sera from normal controls (n = 62), rheumatic disease controls (n = 42), and autoimmune disease patients (n = 86). The frequency of anti-lamin in normal controls was 85.5%, and ranged from 77 to 100% in the other groups. Anti-lamin frequency was not related to age, sex, or disease duration. Reactivity with lamin A or with minor lamins only was observed with 7 various sera and 2 normal sera, respectively. Between groups, the proportions of reactive sera were not different for lamins AC (18-47%) and for lamin B (22-36%). In particular, anti-lamin B and anti-lamins AC were not more common in SLE or CAH than in normal sera. The most frequent lamin specificity of SLE sera was anti-lamins ABC. Anti-lamin isotypes were IgG and/or IgM. Titers of IgM antibodies were not higher in any group. However, IgG anti-lamin titers were higher in CAH than in normal, ankylosing spondylitis, or SLE sera. The highest end point titers (greater than or equal to 1:3200) were observed with CAH, SLE, and rheumatoid arthritis (RA) sera with IgG anti-lamins AC, B, or ABC, or with IgM anti-lamins ABC. None of these SLE and RA patients had evidence of liver disease. Reactivity with minor lamins was more frequent in CAH. We conclude that anti-lamin autoantibodies are present in sera from most individuals and that the highest titers are found in sera from patients with autoimmune diseases.     

Linkage of rheumatoid arthritis to the candidate gene NRAMP1 on 2q35.

The macrophage resistance gene NRAMP1 regulates priming/activation of macrophages for enhanced TNF alpha, IL 1 beta, and MHC class II expression. Since all of these functions are of potential importance in the induction or maintenance or both of autoimmune disease, samples from the Arthritis and Rheumatism Council's repository of multicase rheumatoid arthritis families were typed for a dinucleotide repeat in the NRAMP1 promoter region and four other 2q34 (TNP1) or 2q35 (IL8R, VIL1, DES) marker genes. Identity by descent (IBD) sib pair analysis using a three locus haplotype NRAMP1-IL8RB-VIL1, or NRAMP1 alone, provided preliminary evidence (maximum lod score = 1.01, p = 0.024) for a gene in this region contributing to suceptibility to rheumatoid arthritis. Candidacy for NRAMP1 as the disease susceptibility gene was supported by a significant bias (p = 0.048) towards transmission of the NRAMP1 promoter region allele 3 in affected offspring.     

Smith-Fineman-Myers综合征与X连锁核蛋白基因的连锁分析

目的 明确Smith-Fineman-Myers综合征（Smith-Fineman-Myers syndrome,SFMS)与X连锁核蛋白(X-linked unclear protein,XNP）基因之间的连锁关系。方法 采用聚合酶链反应结合变性聚丙烯酰胺凝胶电泳方法，分析SFMS家系中各成员XNP基因内多态位点基因型。结果 两个多态位点中，XNPSTR1有多态，家系分析结果表明XNP基因与SFMS致病基因之间存在重组。结论 XNP基因不是导致中国山东SFMS家系的致病基因，SFMS存在位点异质性。     

Relationship of serotonin transporter gene polymorphisms and haplotypes to mRNA transcription.

The serotonin transporter (5HTT; chromosomal location 17q12) is an important regulator of serotonergic neurotransmission and is the site of action for a number of antidepressant medications. Sequence variation at a VNTR known as the 5HTTLPR, which is 1.4 kb upstream of the translation start of 5HTT, has been associated in some studies with increased vulnerability to depression, neuroticism, and autism. Support for these clinical observations has included laboratory findings that 5HTTLPR variation is associated with changes in 5HTT gene translation. We re-examined these earlier laboratory findings by directly measuring 5HTT mRNA levels and genotyping four loci spanning the 5HTT gene using RNA and DNA prepared from 85 independent lymphoblast cell lines. Using this data, haplotypes were inferred and the resulting single point and haplotypes data analyzed by univariate and regression analyses. Consistent with the original findings, we found a significant effect of the 5HTTLPR on mRNA production. In contrast to previous reports, the effect on 5HTT mRNA production appeared to be mediated through an additive, not dominant, mechanism. Neither genotype nor haplotype at three other 5HTT loci were associated with alterations in mRNA production, although the small number of samples homozygous for the three most common haplotypes limits these findings. We conclude that further examination of the role of 5HTT sequence variation in regulating 5HTT mRNA production is warranted.