Dwarfism Research Today is a free monthly online journal that collates and summarizes the latest research about Dwarfism, including details on genetics, diet, mental and motor development.

Microcephalin and pericentrin regulate mitotic entry via centrosome-associated Chk1.

Tibelius A, Marhold J, Zentgraf H, Heilig CE, Neitzel H, Ducommun B, Rauch A, Ho AD, Bartek J, Krämer A

Clinical Cooperation Unit Molecular Hematology/Oncology and 2 Department of Tumor Virology, German Cancer Research Center, 69120 Heidelberg, Germany.

Primary microcephaly, Seckel syndrome, and microcephalic osteodysplastic primordial dwarfism type II (MOPD II) are disorders exhibiting marked microcephaly, with small brain sizes reflecting reduced neuron production during fetal life. Although primary microcephaly can be caused by mutations in microcephalin (MCPH1), cells from patients with Seckel syndrome and MOPD II harbor mutations in ataxia telangiectasia and Rad3 related (ATR) or pericentrin (PCNT), leading to disturbed ATR signaling. In this study, we show that a lack of MCPH1 or PCNT results in a loss of Chk1 from centrosomes with subsequently deregulated activation of centrosomal cyclin B-Cdk1.

Published 23 June 2009 in J Cell Biol.
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Articles on Dwarfism published 22 June 2009:

Overexpression of two chrysanthemum DgDREB1 group genes causing delayed flowering or dwarfism in Arabidopsis.   Plant Mol Biol.

We isolated 13 DREB1 (dehydration responsive element binding factor 1) genes from chrysanthemum and further divided them into three groups, DgDREB1A, DgDREB1B and DgDREB1C, based on the phylogenetic analysis. Each group showed their unique expression patterns under cold, dehydration and salt stress conditions. Arabidopsis plants overexpressing DgDREB1A (1A plants) exhibited significantly stronger tolerance to freezing and drought than those overexpressing DgDREB1B (1B plants) and the control ... [Abstract] [Full-text]

Articles on Dwarfism published 11 June 2009:

A spontaneous mutation of the Wwox gene and audiogenic seizures in rats with lethal dwarfism and epilepsy.   Genes Brain Behav.

The lde/lde rat is characterized by dwarfism, postnatal lethality, male hypogonadism, a high incidence of epilepsy and many vacuoles in the hippocampus and amygdala. We used a candidate approach to identify the gene responsible for the lde phenotype and assessed the susceptibility of lde/lde rats for audiogenic seizures. Following backcross breeding of lethal dwarfism with epilepsy (LDE) to Brown Norway rats, the lde/lde rats with an altered genetic background showed all pleiotropic phenotypes. ... [Abstract] [Full-text]

Maternal age-specific risk of non-chromosomal anomalies.   BJOG, 116(8): 1111-9.

OBJECTIVES: To determine the excess risk of non-chromosomal congenital anomaly (NCA) among teenage mothers and older mothers. DESIGN AND SETTING: Population-based prevalence study using data from EUROCAT congenital anomaly registers in 23 regions of Europe in 15 countries, covering a total of 1.75 million births from 2000 to 2004. PARTICIPANTS: A total of 38,958 cases of NCA that were live births, fetal deaths with gestational age > or = 20 weeks or terminations of pregnancy following ... [Abstract] [Full-text]

Articles on Dwarfism published 10 June 2009:

A novel ENU-induced mutation, peewee, causes dwarfism in the mouse.   Mamm Genome.

We identified a novel fertile autosomal recessive mutation called peewee that results in dwarfing, in a region-specific ENU-induced mutagenesis. These mice at litter size were smaller those of other strains. Histological analysis revealed that the major organs appear normal, but abnormalities in cellular proliferation were observed in bone, liver, and testis. Haplotype analysis localized the peewee gene to a 3.3-Mb region between D5Mit83 and D5Mit356.3. There are 18 genes in this linkage area. ... [Abstract] [Full-text]

Articles on Dwarfism published 9 June 2009:

Altered expression of cytosolic/nuclear HSC70-1 molecular chaperone affects development and abiotic stress tolerance in Arabidopsis thaliana.   J Exp Bot, 60(9): 2653-64.

Molecular chaperones of the heat shock cognate 70 kDa (HSC70) family are highly conserved in all living organisms and assist nascent protein folding in normal physiological conditions as well as in biotic and abiotic stress conditions. In the absence of specific inhibitors or viable knockout mutants, cytosolic/nuclear HSC70-1 overexpression (OE) and mutants in the HSC70 co-chaperone SGT1 (suppressor of G(2)/M allele of skp1) were used as genetic tools to identify HSC70/SGT1 functions in ... [Abstract] [Full-text]

Articles on Dwarfism published 3 June 2009:

Sanfilippo syndrome type C: mutation spectrum in the heparan sulfate acetyl-CoA: alpha-glucosaminide N-acetyltransferase (HGSNAT) gene.   Hum Mutat, 30(6): 918-25.

Mucopolysaccharidosis (MPS) type IIIC or Sanfilippo syndrome type C is a rare autosomal recessive disorder caused by the deficiency of the lysosomal membrane enzyme, heparan sulfate acetyl-CoA (AcCoA): alpha-glucosaminide N-acetyltransferase (HGSNAT; EC 2.3.1.78), which catalyzes transmembrane acetylation of the terminal glucosamine residues of heparan sulfate prior to their hydrolysis by alpha-N-acetylglucosaminidase. Lysosomal storage of undegraded heparan sulfate in the cells of affected ... [Abstract] [Full-text]

Articles on Dwarfism published 2 June 2009:

IGF-I replacement therapy in children with congenital IGF-I deficiency (Laron syndrome) maintains heart dimension and function.   Growth Horm IGF Res, 19(3): 280-2.

OBJECTIVE: Untreated patients with congenital growth hormone deficiency (GHD) and IGF-I deficiency are characterized not only by dwarfism but also by acromicria and organomicria, such as the heart. We assessed cardiac dimensions and function in very young patients with Laron syndrome (LS) undergoing IGF-I replacement therapy. DESIGN: Two to seven echocardiographic measurements were performed during IGF-I replacement therapy on male (n=4) and female (n=4) LS -patients, mean+/-SD age of 7.1+/-3.6 ... [Abstract] [Full-text]

Articles on Dwarfism published 28 May 2009:

Human DNA damage response and repair deficiency syndromes: Linking genomic instability and cell cycle checkpoint proficiency.   DNA Repair (Amst).

A plethora of clinically distinct human disorders exist whose underlying cause is a defect in the response to or repair of DNA damage. The clinical spectrum of these conditions provides evidence for the role of the DNA damage response (DDR) in mediating diverse processes such as genomic stability, immune system function and normal human development. Cell lines from these disorders provide a valuable resource to help dissect the consequences of compromised DDR at the molecular level. Here we ... [Abstract] [Full-text]

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