0000000000026157
AUTHOR
Brendan Lee
SPOC1, a novel PHD-finger protein: association with residual disease and survival in ovarian cancer.
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. I…
Mutations in LMX1B cause abnormal skeletal patterning and renal dysplasia in nail patella syndrome
The LIM-homeodomain protein Lmxlb plays a central role in dorso-ventral patterning of the vertebrate limb1. Targeted disruption of Lmxlb results in skeletal defects including hypoplas-tic nails, absent patellae and a unique form of renal dysplasia (see accompanying manuscript by H. Chen et al.; ref. 2). These features are reminiscent of the dominantly inherited skeletal malformation nail patella syndrome (NFS). We show that LMX1B maps to the NFS locus and that three independent NFS patients carry de novo heterozygous mutations in this gene. Functional studies show that one of these mutations disrupts sequence-specific DNA binding, while the other two mutations result in premature terminatio…
Yunis-Varón Syndrome Is Caused by Mutations in FIG4, Encoding a Phosphoinositide Phosphatase
Yunis-Varón syndrome (YVS) is an autosomal-recessive disorder with cleidocranial dysplasia, digital anomalies, and severe neurological involvement. Enlarged vacuoles are found in neurons, muscle, and cartilage. By whole-exome sequencing, we identified frameshift and missense mutations of FIG4 in affected individuals from three unrelated families. FIG4 encodes a phosphoinositide phosphatase required for regulation of PI(3,5)P(2) levels, and thus endosomal trafficking and autophagy. In a functional assay, both missense substitutions failed to correct the vacuolar phenotype of Fig4-null mouse fibroblasts. Homozygous Fig4-null mice exhibit features of YVS, including neurodegeneration and enlarg…
Regulation of glomerular basement membrane collagen expression by LMX1B contributes to renal disease in nail patella syndrome.
Basement membrane (BM) morphogenesis is critical for normal kidney function. Heterotrimeric type IV collagen, composed of different combinations of six alpha-chains (1-6), is a major matrix component of all BMs (ref. 2). Unlike in other BMs, glomerular BM (GBM) contains primarily the alpha 3(IV) and alpha 4(IV) chains, together with the alpha 5(IV) chain. A poorly understood, coordinated temporal and spatial switch in gene expression from ubiquitously expressed alpha 1(IV) and alpha 2(IV) collagen to the alpha 3(IV), alpha 4(IV) and alpha 5(IV) chains occurs during normal embryogenesis of GBM (ref. 4). Structural abnormalities of type IV collagen have been associated with diverse biological…
Mutation Analysis of LMX1B Gene in Nail-Patella Syndrome Patients
SummaryNail-patella syndrome (NPS), a pleiotropic disorder exhibiting autosomal dominant inheritance, has been studied for >100 years. Recent evidence shows that NPS is the result of mutations in the LIM-homeodomain gene LMX1B. To determine whether specific LMX1B mutations are associated with different aspects of the NPS phenotype, we screened a cohort of 41 NPS families for LMX1B mutations. A total of 25 mutations were identified in 37 families. The nature of the mutations supports the hypothesis that NPS is the result of haploinsufficiency for LMX1B. There was no evidence of correlation between aspects of the NPS phenotype and specific mutations.
Expression profiling of human fetal growth plate cartilage by EST sequencing.
The differentiation of mesenchymal stem cells into hypertrophic chondrocytes is an integral and multistep process important in pattern formation, endochondral ossification, and postnatal growth of the skeleton. In recent years, novel genes involved in these processes have been identified, but still only little is known about the large-scale gene expression profile during skeletal development. We initiated an expressed sequence tag (EST) project aiming at the identification of genes and pathways involved in this complex process. Candidate genes are expected to be of value for diagnosis and treatment of monogenic and multigenic heritable disorders of the skeleton. Here, we describe the sequen…