Charcot-Marie-Tooth disease type 1A (CMT1A) is associated with duplication of chromosome 17p11.2-p12, whereas hereditary neuropathy with liability to pressure palsies (HNPP), which is an autosomal dominant neuropathy showing characteristics of recurrent pressure palsies, is associated with 17p11.2-p12 deletion. An altered gene dosage of PMP22 is believed to the main cause underlying the CMT1A and HNPP phenotypes. Although CMT1A and HNPP are associated with the same locus, there has been no report of these two mutations within a single family. We report a rare family harboring CMT1A duplication and HNPP deletion.
Charcot-Marie-Tooth Disease ; Gene Dosage ; Humans ; Paralysis ; Phenotype

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder. Widespread presence of glial cytoplasmic inclusions is the neuropathologic hallmark of MSA. The disease has long been considered as a sporadic disorder. However, in recent years, a few familial cases of MSA have been reported, and researches have verified certain genetic variants could increase the risk of MSA. These indicated genetic factors may play an imported role in the pathogenesis of MSA. In this review, the emerging evidence in favor of genetic players in MSA is discussed.
Animals ; Gene Dosage ; Genetic Research ; Humans ; Multiple System Atrophy ; genetics

Congenital Abnormalities ; genetics ; Gene Dosage ; Genome, Human ; Humans

OBJECTIVETo examine the feasibility of linking operons in tandem to enhance expression of heterologous genes in Escherichia coli (E. coli) and clarify the potential control mechanism of the total plasmid DNA amount in each host cell.

METHODSTwo series of expression plasmids, CW11 and CW12, containing 1 to 4 and 1 to 3 heterologous gene operon(s) respectively, were constructed. The molecular size of the CW11 series varied from 5.47 kb to 12.26 kb in 2.25 kb increments. The CW12 series varied from 5.40 kb to 9.72 kb in 2.16 kb increments. The expression level of desired protein was assayed by SDS-PAGE and laser density scanning. Plasmid copy number was determined by incorporation with (3)H-thymidine ((3)H-TdR).

RESULTSNo influence of the tandem-joined operons on host growth and plasmid stability was observed. Upon induction, the desired protein accumulations in the CW11 series were 44.9% +/- 3.9%, 51.3% +/- 4.1%, 54.8% +/- 3.3% and 58.2% +/- 3.4% of total cell protein. In the CW12 series, the yields were 32.2% +/- 5.0%, 42.8% +/- 4.1% and 46.9% +/- 4.0% of total cell protein. As size increased, the plasmid copy number decreased, but target gene dosage increased significantly (P < 0.01). Further calculation showed that the total amount of plasmid DNA per cell was not significantly different in each series (P > 0.05) and restricted to some extent.

CONCLUSIONSIncreasing the target gene dosage by tandem linking of operons may enhance the expression level of a desired protein. Although the size (kb) and the copy number of each plasmid are negatively interrelated, for certain plasmids in each series, their total DNA amount per cell seems to be a restricted constant for specific E. coli strains under identical incubation condition.

OBJECTIVETo investigate the correlation of the deleted azoospermia (DAZ) gene copy related to gr/gr and b2/b3 deletions in the AZFc region with male spermatogenic impairment.

METHODSThis study included 121 infertile men with different de- grees of spermatogenic impairment and 95 healthy donors from the sperm bank. Using PCR, PCR-RFLP, and Y chromosome specific sequence tagged sites (STS) , we analyzed the association of DAZ gene copy deletions related to gr/gr and b2/b3 deletions in the AZFc region with spermatogenic impairment.

RESULTSThere were 15 cases of gr/gr deletion (12. 40% ) and 6 cases of b2/b3 deletion (4.96%) in the infertility group as compared with 13 cases of gr/gr deletion (13.68%) and 1 case of b2/b3 deletion (1.05%) in the control. Analysis of the DAZ-specific single nucleotide variant (SNV) loci revealed 11 gr/gr-DAZI/DAZ2 deletions (9.09%), 4 gr/gr-DAZ3/DAZ4 deletions (3.31%), and 6 b2/b3-DAZ1/DAZ2 deletions (4.96%) in the infertile men in comparison with 3 gr/ gr-DAZ1/DAZ2 deletions (3.16%), 10 gr/gr-DAZ3/DAZ4 deletions (10.53%), and 1 b2/b3- DAZ3/DAZ4 deletion (1.05%) in the control.

CONCLUSIONPartial deletions of gr/gr and b2/b3 exist in both healthy men and male patients with different degrees of spermatogenic impairment and cannot be considered as a risk factor for spermatogenesis impairment. However, deletions of different DAZ duplicons in gr/gr and b2/b3 deletions have different effects on spermatogenesis. DAZ1/DAZ2 instead of DAZ3/DAZ4 deletions might be associated with spermatogenesis impairment.

Gene dosage determination is increasingly important for the study of both genome variation and rearrangement associated with complex diseases. Large genomic duplications and deletions are increasingly found as the causes. Methods such as PCR or sequencing are usually qualitative rather than quantitative. Thus, these methods can not detect large genomic duplications or deletions. Therefore, searching for a gene dosage method which is reliable, sensitive and high-throughput becomes imperative. Many high-performance technologies have been developed for gene dosage analyses in the recent years. There are generally three categories of methods including cytogenetic, Southern or dot blotting, or PCR amplification. Recent development in these techniques have been introduced and discussed in this review, which will help people to choose a suitable method for different research.
Blotting, Southern ; methods ; Cytogenetic Analysis ; methods ; Gene Deletion ; Gene Dosage ; genetics ; Gene Duplication ; Humans ; Polymerase Chain Reaction ; methods

Animals ; Cations ; chemistry ; Chitin ; administration & dosage ; analogs & derivatives ; chemistry ; Chitosan ; DNA ; administration & dosage ; Gene Transfer Techniques ; Genetic Therapy ; Liposomes ; administration & dosage ; chemistry ; Polylysine ; administration & dosage ; chemistry

Targeting drug delivery system (TDDS) is one of the most concerned research fields in cancer treatment because it can bind selectively and react with the target diseased sites at the cellular or sub-cellular level, making distribution and release of drugs in a controlled manner, thus enhance therapeutic effects and reduce toxic and side-effects on normal cells. Polyamidoamine dendrimer (PAMAMD) is a kind of newly developed polymer in nanometer degree. Hyper-branched, monodispersity, three-dimensional structure and host-guest entrapment ability make it used as drug carrier, gene delivery system and imaging agent. Various targeting ligands, which have high affinity to specific organs, tissues or cells in human body, can be linked to surface functional groups of PAMAMD. And drugs and theoretical gene are carried by encapsulation or chemical conjugation. Finally, PAMAMD targeting drug delivery system can carry drugs and theoretical gene to diseased sites and then release them for targeted therapy. The PAMAMD-based conjugates have small size, ligh permeability and retention effect (EPR), low toxicity and so on. The research progress of PAMAMD modified by different ligands in targeting drug delivery system is reviewed, and research direction of the PAMAMD targeting delivery system in the future is also suggested.
Amino Acids ; administration & dosage ; chemistry ; Animals ; Antibodies, Monoclonal ; administration & dosage ; chemistry ; Antineoplastic Agents ; administration & dosage ; therapeutic use ; Biotin ; administration & dosage ; chemistry ; Dendrimers ; administration & dosage ; chemistry ; Drug Carriers ; administration & dosage ; chemistry ; Drug Delivery Systems ; Folic Acid ; administration & dosage ; chemistry ; Gene Transfer Techniques ; Humans ; Ligands ; Neoplasms ; drug therapy ; Polyamines ; administration & dosage ; chemistry ; pharmacokinetics ; Polyethylene Glycols ; administration & dosage ; chemistry ; Transferrin ; administration & dosage ; chemistry

How to reduce immune response is an unprecedented challenge for rAAV gene medicine. Recent studies suggested that lowering dosage of the vector used could reduce immune response caused by rAAV gene medicine. Nevertheless, it would also decrease the transgene expression, leading to failure of gene treatment. It is therefore important to take appropriate steps to maintain high gene expression level and pharmacodynamic, while the dosage of rAAV used is reduced. Here, steps to enhancing gene therapy, such as optimization of the administration, reconstruction of the viral vector and selection of the promoter, are discussed in order to achieve maximum outcome.
Animals ; Dependovirus ; genetics ; immunology ; Dose-Response Relationship, Drug ; Gene Dosage ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; administration & dosage ; genetics ; immunology ; Humans ; Recombination, Genetic ; Transgenes ; genetics

BACKGROUND: The skin changes of X-linked recessive ichthyosis are cnused by the deficiency of the enzyme steroid sulfatase, which usually results from deletions of this gene in Caucasian populations. OBJECTIVE AND MEHTODS: To disgnose X-linked recessive ichthyosis and detect its carrier, we have investigated distinctive gene deletion and measured gene dosage of steroid sulfatase gene by southern blot hybridization in Korean patients with X-linked recessive ichthyosis. RESULTS: Patients from 8 of 9 unrelated families exhibited deletions, if the steroid sulfatase gene. Of 6 families showing a family history compatible with X-linked recessive inheritance, One family exhibited a normal pattern of hybridization. All but one family showed deletion of steroid sulfatase gene. All three patients lacking a fami1y history of the disease exhibited gene deletions. The ratio of the steroid sulfatsse specific band density to the Factor VIII specific band density was measured in 8 obligate carriers using a laser densitometer. The average ratio exhibited by the car riers was less than half that of normal women. Conclusian: These results suggest that the X-linked recessive ichth osis patient and its carrier can also be diagnosed and detected by Southern blot hybridization of steroid sulfatase gene in Korea.
Blotting, Southern* ; Diagnosis* ; Factor VIII ; Female ; Gene Deletion ; Gene Dosage ; Humans ; Ichthyosis* ; Korea ; Skin ; Steryl-Sulfatase ; Wills