135G/C polymorphism in the RAD51 gene and acute myeloid leukemia risk: a meta-analysis

Numerous studies have evaluated the association between the 135G/C polymorphism in the RAD51 gene and risk of acute myeloid leukemia (AML), but the results have been inconsistent. The aim of this study is to precisely examine the association between the 135G/C polymorphism in the RAD51 gene and AML risk through a meta-analysis. PubMed, Google Scholar, and Web of Science databases were systematically searched to identify relevant studies from their inception to June 2015. Pooled odds ratios (OR) with 95% confidence intervals (95%CI) were calculated using fixed- or random-effect models. A total of 6 case-control studies containing 1432 patients and 2750 controls were used in this meta-analysis, and our results showed no association between the 135G/C polymorphism in the RAD51 gene and AML risk (CC vs GG: OR = 1.67, 95%CI = 0.93-3.02; GC vs GG: OR = 1.24, 95%CI = 0.80-1.92; the dominant model: OR = 1.26, 95%CI = 0.83-1.91; the recessive model: OR = 1.63, 95%CI = 0.90-2.95). No publication bias was found in this study. In summary, the present meta-analysis suggests that the 135G/C polymorphism in the RAD51 gene may not be associated with AML risk. However, further studies with larger cohorts are needed to confirm this conclusion.

Mutation L437P in the 2B domain of keratin 1 causes diffuse palmoplantar keratoderma in a Chinese pedigree

Diffuse palmoplantar keratoderma (DPPK) is an autosomal dominant genodermatosis characterized by uniform hyperkeratosis of the palm and sole epidermis. This disorder can be caused by mutations in the genes keratin 1, keratin 9, keratin 16, desmoglein 1 and plakoglobin. Here we present a DPPK Chinese pedigree and identify the aetiology as a novel missense mutation, L437P, located in a highly conserved helix motif in domain 2B of KRT1. Functional analysis shows that overexpression of the L437P mutant in cultured cells leads to abnormal intermediate filament networks and filament aggregation. This gain-of-function mutation highlights the role of domain 2B in mediating filament assembly.

An improved mechanical technique for assisted hatching

BACKGROUND

Varied clinical outcomes of assisted hatching (AH) have been reported. We attempt to investigate whether the size of the zona opening created by AH is adequate for blastocyst hatching, and, if not, set up a new method to improve it.

METHODS

A new AH technique, long zona dissection (LZD), was established, and experiments were performed to compare the effects of different sizes of zona opening on complete hatching of blastocysts in mouse and human embryos in vitro.

RESULTS

The LZD technique can create a long zona slit on early embryos, even blastocysts, with the slit size beyond two-thirds of zona diameter. Compared with three-dimensional partial zona dissection, LZD can significantly enhance the hatching speed and the rate of complete hatching of mouse blastocysts (93.9%). All (100%) human blastocysts completely hatched following LZD; however, when the slit size after AH was about two-fifths of zona diameter, more of the larger inner cell masses (ICM) became trapped by the zona opening during hatching than the smaller ICM (53.3 versus 12.5%, P = 0.01).

CONCLUSIONS

Zona opening of moderate size following AH is inadequate for the completion of blastocyst hatching in vitro; in some cases, however, it can be significantly improved by LZD.

Confirmation and refinement of a genetic locus for disseminated superficial actinic porokeratosis (DSAP1) at 12q23.2-24.1

BACKGROUND

Our previous study has identified two loci for disseminated superficial actinic porokeratosis (DSAP), but the genes responsible are still unknown.

OBJECTIVES

To narrow down the candidate regions and to assess candidate genes.

METHODS

A genome-wide scan and linkage analysis were carried out in a newly collected five-generation Chinese family with DSAP. In addition, six candidate genes were screened for possible DSAP-associated mutations.

RESULTS

DSAP in this family was associated with chromosome 12q. Fine mapping and haplotype construction refined the DSAP1 locus to a 4.4-cM interval. No disease-associated mutation was detected in CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 or KIAA0789 genes.

CONCLUSIONS

The DSAP1 locus was localized to a 4.4-cM interval at chromosome 12q23.2-24.1. CRY1, C4ST1, TXNRD1, HCF2, CMKLR1 and KIAA0789 genes were not associated with DSAP1.

A novel locus (DSAP2) for disseminated superficial actinic porokeratosis maps to chromosome 15q25.1-26.1

BACKGROUND

Disseminated superficial actinic porokeratosis (DSAP) is a chronic cutaneous disorder characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. It develops in teenagers in sun-exposed areas of skin and usually follows an autosomal dominant inheritance pattern. The first locus for DSAP was localized to chromosome 12q23.2-24.1, but no gene responsible for porokeratosis has been identified to date.

OBJECTIVES

To determine whether DSAP is a genetically heterogeneous disorder and to identify the disease gene locus in a three-generation Chinese family with DSAP.

METHODS

Genetic linkage analysis was carried out in this family using 15 microsatellite markers between D12S1671 and D12S369 on chromosome 12q, followed by a genome-wide scan with 382 microsatellite markers from the autosomes.

RESULTS

Genetic linkage analysis with chromosome 12q markers suggested that the locus in this family is not linked to chromosome 12q. A genome-wide scan and fine mapping finally localized the locus for DSAP in this family to a 6.4-cM region between markers D15S1023 and D15S1030 at chromosome 15q25.1-26.1. This DSAP locus was named DSAP2.

CONCLUSIONS

The previous results and this study have shown that DSAP is a genetically heterogeneous disorder; a novel locus for DSAP, termed DSAP2, was mapped to a 6.4-cM region between markers D15S1023 and D15S1030.

[Culture and characterization of human peritoneal mesothelial cells]

OBJECTIVE

To establish a reproducible model for culture of human peritoneal mesothelial cells (HPMCs), and observe the expressions of extracellular matrix (ECM) protein and interleukin-8 (IL-8) in HPMC.

METHODS

Mesothelial cells were isolated from human omenta by trypsin EDTA disaggregation. HPMCs were identified by morphology and streptomyces protein-peroxidase (SP) method. In the same way, expressions of fibronectin, collagen type III, V and transforming growth factor beta 1 (TGF beta 1) were measured. Expression of IL-8 mRNA and FN mRNA in the HPMCs was detected by reverse transcription (RT) and polymerase chain reaction (PCR) amplification.

RESULTS

Confluent HPMCs appeared multipolar under microscope; numerous surface microvilli and an abundant endoplasmic reticulum were observed. Cultured HPMCs coexpressed cytokeratin and vimentin, and synthesized fibronectin, TGF beta 1 and collagen types III (instead of type V). Expressions of IL-8 mRNA and FN mRNA were also observed in HPMCs.

CONCLUSION

Establishment of cultured HPMCs model will provide the basis of the research in preventment of peritoneal fibrosis and roles of IL-8 in peritoneal dialysis.

Identification of a locus for disseminated superficial actinic porokeratosis at chromosome 12q23.2-24.1

Disseminated superficial actinic porokeratosis is an autosomal dominant cutaneous disorder characterized by many uniformly small, minimal, annular, anhidrotic, and keratotic lesions. The genetic basis for this disease is unknown. Using a genomewide search in a large Chinese family, we identified a locus at chromosome 12q23.2-24. 1 responsible for disseminated superficial actinic porokeratosis. The fine mapping study indicates that the disseminated superficial actinic porokeratosis gene is located within a 9.6 cM region between markers D12S1727 and D12S1605, with a maximum two-point LOD score of 20.53 (theta = 0.00) at D12S78. This is the first locus identified for a genetic disease where the major phenotype is porokeratosis. The study provides a map location for isolation of a gene causing disseminated superficial actinic porokeratosis.

[Localization of the gene for 4 hereditary multiple exostoses families]

We investigated 11 families with hereditary multiple exostoses (EXT) by linkage analysis using 8 short-tandem-repeat (CA)n polymorphic markers on chromosomes 8, 11 and 19. The Lod score in four families indicated that the gene responsible for EXT is located in the pericentromeric region of chromosome 11.

[Identification of the origin of 7q+ marker chromosome in a mental retard patient]

The present chromosome-specific and chromosome-band-specific probe pools constructed by the technique of human chromosome microdissection and PCR were taken as painting probes. Using the forward chromosome painting and chromosome screening method, we had identified a chromosome additional fragment of a 7 q+ marker chromosome in a patient originated from 3 q 26-->3 qter, and ascertained the patient's karyotype was 46, XX, -7, + der (7) t (7;3) (7 pter-->7 q 32::3 q 26-->3 qter). Applying this strategy, we can identify the origin of marker chromosomes fastly and effectively.

[Construction and application of the chromosomal specific probe pool from human chromosome no. 7]

We constructed a chromosomal specific probe pool from human chromosome No. 7 using the techniques of chromosomal microdissection, PCR and chromosomal painting. A patient's pedigree with an abnormal chromosome No. 7 were analysed by the above probe pool.