Fibroblast growth factor receptor 3 (FGFR3) is a glycoprotein that belongs to the family of tyrosine kinase receptors. Specific mutations in the FGFR3 gene are associated with autosomal dominant human skeletal disorders such as hypochondroplasia, achondroplasia, and thanatophoric dysplasia. Hypochondroplasia (HCH), the mildest form of this group of short-limbed dwarfism disorders, results in approximately 60% of cases from a mutation in the intracellular FGFR3-tyrosine kinase domain. The remaining cases may either be caused by defects in other FGFR gene regions or other yet unidentified genes. We describe a novel HCH mutation, the first found outside the common mutation hot spot of this condition. This point mutation, an N328I exchange in the extracellular Ig domain III of the receptor, seems to be unique as it affects a putative N-glycosylation site that is conserved between different FGFRs and species. The amino acid exchange itself most probably has no impact on the three-dimensional structure of the receptor domain, suggesting that the phenotype is the result of altered receptor glycosylation and its pathophysiological consequences.

Sulfation of proteoglycans is a very important

We report the identification of a novel human gene (SPOC1) which encodes a protein with a PHD-finger domain. The gene is located in chromosomal region 1p36.23, a region implicated in tumor development and progression. RNA in situ hybridization experiments showed strong SPOC1 expression in some rapidly proliferating cell types, such as spermatogonia, but not in nonproliferating mature spermatocytes. In addition, high SPOC1 mRNA expression was observed in several ovarian cancer cell lines. This prompted us to systematically examine SPOC1 expression in ovarian cancer in relation to prognosis. SPOC1 mRNA expression was quantified in tumor tissue of 103 patients with epithelial ovarian cancer. Interestingly, SPOC1 was associated with residual disease, whereby patients with unresectable tumors showed higher levels compared to patients without residual tumor tissue after surgery ( p = 0.029). The univariable proportional hazards model showed an association between SPOC1 expression and survival ( p = 0.043, relative risk = 1.535). Median survival time was 1,596 days for patients with low SPOC1 expression vs. only 347 days for patients with high expression, using Kaplan-Meier analysis. However, SPOC1 was not associated with survival when multivariable analysis was adjusted for residual disease. This can be explained by the correlation between residual disease and SPOC1 expression. In conclusion, SPOC1 is a novel PHD-finger protein showing strong expression in spermatogonia and ovarian cancer cells. SPOC1 overexpression was associated with unresectable carcinomas and shorter survival in ovarian cancer. ' 2005 Wiley-Liss, Inc.

We report on a 4-year-old boy with the typical phenotype of Grebe dysplasia born to consanguineous parents. The father seems to be unaffected; the mother presents with brachydactyly type C (BdC). PCR amplification and sequencing of the cartilage-derived morphogenetic protein 1 (CDMP1) gene of the parents led to the identification of a heterozygous insertion of a single G at nucleotide 206. The mutation that causes frameshift and premature termination is predicted to result in functional haploinsufficiency. The child is homozygous for the insertion (insG206). The phenotypic spectrum of this loss-of-function mutation ranges from normal or BdC in heterozygotes to Grebe-type chondrodysplasia in the homozygously affected and seems to be due to CDMP1 gradient effects during pattern formation. A dominant negative action on other bone morphogenetic proteins is unlikely to cause the severe disruption of skeletogenesis seen in this case of Grebe dysplasia.

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