Progress in molecular diagnosis of fragile X syndrome / 中华医学遗传学杂志

Fragile X mental retardation 1 is the gene underlying fragile X syndrome (FXS). Its product, fragile X mental retardation protein, is closely involved with development of brain and neurons. PCR and Southern blotting have been the major methods for laboratory diagnosis of FXS. In this article, the progress in the molecular diagnosis of FXS is reviewed.

Identification of a mosaic mutation of NF1 gene in a sporadic case of neurofibromatosis type 1 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect NF1 gene mutation in a patient with neurofibromatosis type 1.</p><p><b>METHODS</b>Five fragments encompassing the entire coding sequence of the NF1 gene were amplified with reverse transcription PCR. PCR products were directly sequenced. Suspected mutations were verified by sequencing of DNA amplified by PCR using genomic DNA as template. Corresponding exon of family members was also sequenced. Furthermore, the PCR products were inserted into a pGEM-T cloning vector to quantify cells carrying the mutation in different samples derived from the three embryonic layers.</p><p><b>RESULTS</b>The proband's clinical manifestation was consistent with neurofibromatosis type 1. Sequence analysis has identified a novel heterozygous mutation c.7911 C to T (p.Q2510X) in exon 51 of the NF1 gene in the proband. The same mutation was also detected in peripheral blood cells, uroepithelial cells and oral mucosal cells of the proband, though the signals of uroepithelial cells were significantly weaker. By T cloning-sequencing, recombinants carrying the NF1 gene mutation respectively accounted for 42%, 36% and 12% of all peripheral blood cells, oral mucosal cells and uroepithelial cells .</p><p><b>CONCLUSION</b>It is likely that a mutation of NF1 gene has occurred in early embryogenesis of the proband, which in turn has led to generalized mosaicism of neurofibromatosis type 1.</p>

A novel missense mutation resulting in X-linked adrenoleukodystrophy in female heterozygotes of a Chinese family / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify ABCD1 gene mutation in a Chinese family with three heterozygous female patients.</p><p><b>METHODS</b>Four fragments covering the entire coding sequence of the ABCD1 gene from one of the female patients were amplified by reverse transcription-PCR. The PCR products were directly sequenced. The result of sequencing was confirmed by restriction enzyme digestion of PCR products from genomic DNA. Human ABCD1 gene and ALD protein were aligned with those of rat, monkey, mouse and cattle by Clustal X 1.83. Softwares of Motif Scan, TMpred and ESYpred3D were used to predict the effect of the mutation on the structure of the ALD protein.</p><p><b>RESULTS</b>A novel missense mutation, CAC to CGC, was found at codon 283 of the ABCD1 gene from the patient, resulting in the replacement of histidine by arginine. This mutation abolished an Msl I site in the gene. Her son was free from this mutation. The mutated amino acid residue (283H) was highly conservative in evolution, and the mutation caused a dramatic change in the structure of the ALD protein.</p><p><b>CONCLUSION</b>Three female patients heterozygous for ABCD1 gene mutation were first reported in China, and a novel mutation, p.H283R, was identified in this X-ALD family.</p>

Identification of a novel ABCDI gene mutation in 1 Chinese patient with adrenomyeloneuropathy and his family members / 中华神经医学杂志

Objective To identify the ABCD1 gene mutation in a patient suspected with adrenoleukodystrophy (ALD) and perform its gene analysis in his family members to make a definite diagnosis. Methods Total RNA and genomic DNA were extracted from the leukocytes of peripheral blood in the proband and the family members. The ABCD1 coding region of cDNA in the proband was amplified and sequenced. Mutational site in the ABCD1 gene of the proband was further confirmed by PGR and direct sequencing; at the same time, the mutation in the ABCD1 gene of the genomic DNA in the family members was analyzed by direct sequencing. Results Two bases deletions (656_657delGA)were identified and the corresponding mutation of fs R89 was detected in the ABCD1 gene of the proband, which could make the definite diagnosis of ALD that belonged to adrenomyeloneuropathy. The same gene mutation (ALD hemizygote) was noted in his cousin; his mother, younger sister of his mother and his younger female cousin were noted as the ALD carrers. His older sister was noted as ABCD1 normal genotype. Conclusions A novel ABCD1 gene mutation (fs R89) was identified in Chinese patient with ALD. Molecular testing is an effective way in making diagnosis on patient suspected as having X-linked ALD.

Mutation analysis of SMN gene in a patient and his family with spinal muscular atrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform mutation analysis and describe the genotype of the SMN gene in a patient with spinal muscular atrophy (SMA) and his family.</p><p><b>METHODS</b>Deletion analysis of the SMN1 exon 7 by conventional PCR-restriction fragment length polymorphism (RFLP) and allele-specific PCR, and gene dosage of SMN1 and SMN2 by multiplex ligation-dependent probe amplification (MLPA) were performed for the patient and his parents; reverse transcriptase (RT)-PCR and sequencing were performed for the patient. To determine whether the SMN variant was exclusive to transcripts derived from SMN1, the RT-PCR product of the patient was subcloned and multiple clones were sequenced directly; PCR of SMN exon 5 from the genomic DNA of the parents and direct sequencing were performed to confirm the mutation.</p><p><b>RESULTS</b>In SMN1 exon 7 deletion analysis, no homozygous deletion of the SMN1 was observed in the family; the gene dosage analysis by MLPA showed that the patient had 1 copy of SMN1 and 1 copy of SMN2 his father had 2 copies of SMN1 and 2 copies of SMN2, and his mother had 1 copy of SMN1 and no SMN2. A previously unreported missense mutation of S230L was identified from the patient and this mutation was also found in his father.</p><p><b>CONCLUSION</b>A novel missense mutation of S230L was identified in the SMA family and the genotype of the family members were investigated.</p>

Molecular diagnosis of a Chinese pedigree with osteogenesis imperfecta type I / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform molecular diagnosis for a Chinese pedigree with osteogenesis imperfecta type I.</p><p><b>METHODS</b>Thirty pairs of primers were designed to amplify all the 52 exons, exon boundaries and promoter region of the COL1A1 gene from genomic DNA of peripheral blood cells of the family members. The PCR products were purified and directly sequenced. To check the mutation in normal controls, the genomic DNA from peripheral blood cells of the index patient, his mother and 60 normal controls were analyzed by amplification refractory mutation system.</p><p><b>RESULTS</b>A missense mutation of GAT>CAT was identified at codon 1441 of the COL1A1 gene from the family, which resulted in the replacement of aspartic acid by histidine (D1441H). This mutation was not found in a group of 60 normal controls.</p><p><b>CONCLUSION</b>The method for molecular diagnosis of osteogenesis imperfecta was established and a novel COL1A1 gene mutation, D1441H, was identified in the Chinese pedigree with osteogenesis imperfecta type I.</p>

Effect of OA kneepad on apoptosis genes Bcl-2 and p53 expression in articular cartilage cells of experimental knee osteoarthritis / 中国骨伤

<p><b>OBJECTIVE</b>To study the effects of kneepad on expression of Bcl-2 and p53 mRNA of chondrocyte in white rabbits with knee osteoarthritis, so as to explore and treatment mechanism of OA kneepad on apoptosis of chondrocytes of rabbits with knee osteoarthritis in molecular degree.</p><p><b>METHODS</b>Forty-four Japanese healthy 6-month-old rabbits (equal male and female,the weight ranging from 2 to 2.2 kg) were used to establish knee osteoarthritis models by modified Hulth method. The rabbits were randomly divided into 6 groups: normal group, model group, control group (microwave), experimental group 1 (electricity), experimental group 2 (thermal), experimental group 3 (kneepad). Ten rabbits in the normal group were breed with conventional method; 9 rabbits in the model group were breed with conventional method after model made; 9 rabbits in the control group were treated with microwave for 30 minutes, one time daily; 9 rabbits in the experimental group 1 were treated with electricity (density wave) for 30 minutes,one time daily;8 rabbits in the experimental group 2 were treated with hot (hot soft membrane) for 30 minutes, one time daily; 9 rabbits in the experiment group 3 were treated with electrothermal (OA knee pad) for 30 minutes, one time daily. All the rabbits were treated for 16 weeks and then sacrificed. The expressions of Bcl-2 and p53 mRNA of chondrocytes in knee joint were detected by using fluorescence quantitative RT-PCR method.</p><p><b>RESULTS</b>At the 16 hthek,th e OD260/OD280 value range of total RNA extracted from rabbit articular cartilage tissue in each group were all at 1.80 to 2.00,wh ich indicates high RNA purity. The p53 relative mRNA in articular cartilage cells of model group,th e control group,th e experimental group 1 ,r oup 2,gr oup 3 were overexpressed,an d Belc2 mRNA expression levels of articular cartilage cells were low expression,an d compared with the normal group there were significant differences (P < 0.01). Belc2, p53 mRNA expression in articular cartilage cells,th ere were significant differences (P < 0.01) between the control group, experimental group 1, group 2, group 3 and model group. The results between the control group, experimental group 1 ,group 2 and group 3 had significant differences (P < 0.01).</p><p><b>CONCLUSION</b>OA-kneepad can up-regulate the mRNA expression of Bcl-2 as well as down-regulate the mRNA expression of p53, thereby to inhibit the apoptosis of cartilage cells and delay the degeneration of articular cartilage changes.</p>

Genetic polymorphism of sperm-specifically expressed genes and male infertility / 中华男科学杂志

The expression of sperm-specific genes is necessary in spermiogenesis, and the genetic polymorphism of these genes may impair spermatogenesis, leading to male infertility. Mamy investigations have been conducted on the polymorphism of some candidate genes that are specifically expressed in spermiogenesis, the relation of genetic polymorphism with male infertility and its possible mechanism. Further attempts have been made at the explanation of the causes of infertility from the genetic angle.

Prenatal diagnosis of 5 fetuses with high risk of developing spinal muscular atrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform prenatal diagnosis for 5 pregnant women who had given birth to children with spinal muscular atrophy (SMA).</p><p><b>METHODS</b>Thirty to forty mililiters of amniotic fluid was obtained by amniocentesis under ultrasonic monitoring. DNA was extracted directly from sediment of amniotic fluid. Short tandem repeat (STR) profiling was carried out to evaluate the contamination of amniotic DNA by maternal genomic DNA. Two methods, PCR-restriction fragment length polymorphism (PCR-RFLP) and allele-specific PCR, were used to analyze exon 7 of SMN gene from amniotic DNA.</p><p><b>RESULTS</b>Comparing the 16 STR sites of each fetus with those of his/her parents, there was no or little contamination of amniotic DNA by maternal genomic DNA. In conventional PCR-RFLP, part of the PCR product (189 bp) from amniotic DNA of fetus A, C, or D remained intact after digestion with Dra I, while the PCR product from amniotic DNA of fetus B or E was completely digested by Dra I. In allele-specific PCR, exon 7 of both SMN1 and SMN2 gene could be seen when amniotic DNA of fetuses A, C, or D was analyzed, while only exon 7 of SMN2 could be seen when amniotic DNA of fetuses B or E was analyzed.</p><p><b>CONCLUSION</b>Homozygous deletion of SMN1 is not detected in fetuses A, C, and D, predicting that the risk of developing SMA after birth would be extremely low. Homozygous deletion of SMN1 was present in fetuses B and E suggesting high risk of developing SMA after birth.</p>

Avoiding the interference of ABCD1 pseudogenes in the molecular diagnosis of X-linked adrenoleukodystrophy by double amplification refractory mutation system / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To avoid the interference of ABCD1 pseudogenes, the amplification refractory mutation system (ARMS) was used to analyze the mutation of ABCD1 gene in the molecular diagnosis of X-linked adrenoleukodystrophy (ALD).</p><p><b>METHODS</b>The upstream primers (wild primer and mutation primer) were designed according to the principle of primer-design in ARMS. In addition, a common downstream primer was designed in the same way to discriminate ABCD1 gene from its prologous pseudogenes. The genomic DNA isolated from the peripheral blood leukocytes of the family members and normal controls was amplified by PCR.</p><p><b>RESULTS</b>In double ARMS, a specific product of 107bp could be amplified from genomic DNA of the patient with R617C mutation in ABCD1 gene and his mother, while the same product was not found when the genomic DNA of the patient's father and normal controls was used. Thus, the interference of ABCD1 pseudogenes in molecular diagnosis of ALD was excluded successfully at genomic DNA level.</p><p><b>CONCLUSION</b>Double ARMS is a quick and effective method to eliminate the interference of the pseudogenes in detecting ABCD1 gene mutations.</p>

Effect of Intracerebral Transplantation of Mesenchymal Stem Cells Derived from Human Umbilical Cord Blood on Hypoxic-Ischemic Brain Damage in Neonatal Rat / 实用儿科临床杂志

Objective To investigate the therapeutic effect of intracerebral transplantation of mesenchymal stem cells(MSCs) derived from human umbilical cord blood(UCB) on hypoxic-ischemic brain damage(HIBD) in neonatal rat.Methods Twenty samples of human UCB were collected from healthy full-term newborns.MSCs were isolated from human UCB by density gradient centrifugation and purified by adhere cell selection method.For transplantation,P3 human UCB-derived MSCs were labeled by the 5-bromo-2-deoxyuridine (BrdU).Thirty SD rats of 7 d were built for neonatal HIBD model.One rat died and others were divided into transplant group(n=18) and control group(n=11).At the third day after building models,human UCB-derived MSCs were injected into left cortex in transplant group,while PBS of the same volume was injected into the same site in control group at the same time.The seventh day after transplantation,6 rats of transplant group were sacrificed to prepare brain tissue sections.The survival,migration and differentiation of the transplanted cells were investigated by brain tissue immunohistochemical analysis,and nervous function of 2 groups were evaluated by modified neurological severity score(mNSS) on the first,7th,14th,21th and 28th day after transplantation.Results MSCs were isolated from 5 of 20 human UCB samples.Immunocytochemical analysis of brain tissue showed that the transplanted human UCB-derived MSCs could survive and migrate around by the center of transplant site.There were (12.67?2.73)% of MSCs differentiated into astrocyte-like cells.mNSS showed that the score of transplant group was lower than that of control group on the first,7th,14th,21th and 28th day,and the differences of score points between 2 groups on the 14th,21th and 28thday were statistically significant(Pa

Prenatal molecular diagnosis of adrenoleukodystrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To carry out prenatal diagnosis on two fetuses of different pedigrees with X-linked adrenoleukodystrophy (ALD).</p><p><b>METHODS</b>The amniotic fluid was obtained with the help of a clinical doctor and the genomic DNA was isolated from it. Maternal DNA contamination was excluded by fluorescent STR profiling, The R617G mutation found in the first pedigree was searched in genomic DNA of amniotic fluid cells (AFC) from fetus 1 by amplification refractory mutation system (ARMS) and dot DNA hybridization while the P534R mutation found in pedigree 2 was analyzed in the AFC genomic DNA of fetus 2 by restrictive digestion with Hae II and DNA direct sequencing.</p><p><b>RESULTS</b>A specific band (185 bp) was detected from the genomic DNA of the first fetus and his mother by using mutation primer in ARMS but not from that of the first fetus's father and unrelated controls. DNA dots were visualized only in the fetus 1 and carrier when using the mutation probe in DNA hybridization. In the other ALD family, the PCR product (506 bp) of the second fetus which spanned the site of P534R mutation could not be digested with Hae II and no mutation was detected in the ABCD1 gene from the genomic DNA of the fetus 2 by using DNA direct sequencing.</p><p><b>CONCLUSION</b>Fetus 1 had R617G mutation on his ABCD1 gene and he was an adrenoleukodystrophy hemizygote. Fetus 2 had no P534R mutation on his ABCD1 gene and he was a normal hemizygote.</p>

Mutational analysis of three Chinese pedigrees with adrenoleukodystrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the mutational genotype of three Chinese families with X-linked adrenoleukodystrophy (X-ALD: MIM#300100).</p><p><b>METHODS</b>Total RNA was extracted from the peripheral blood leukocytes of patients 1, 2 and the mother of patient 3, using RNA blood Mini kit (QIAGEN). After reverse transcription, cDNA was amplified in four overlapping segments. The PCR products were purified and directly sequenced. To confirm the mutations, the genomic DNA was isolated from the patients and their family members using DNA blood isolation kit (MO-BIO) and analyzed by PCR-restrictive digestion or amplification refractory mutation system.</p><p><b>RESULTS</b>Three distinct mutations were detected in the ABCD1 gene of the three pedigrees. A mutation of CCC-->CGC was detected at codon 534 of the ABCD1 gene from patient 1, resulting in the arginine for proline substitution. A change of GGG-->AGG was found at codon 266 of the second patient's gene, accompanied with the replacement of glycine by arginine. A mutation of CGC-->GGC was found at codon 617 in one ABCD1 allele of the third patient's mother, leading to the glycine for arginine substitution. The three mutations were confirmed through restriction analysis or amplification refractory mutation system.</p><p><b>CONCLUSION</b>Three ABCD1 gene missense mutations were detected in three unrelated Chinese families with X-linked adrenoleukodystrophy, one of which, the mutation (P534R), is novel in Chinese with ALD, and the other two G266R and R617G mutations, have been reported outside China.</p>

Advances in researches on lactate dehydrogenase-C4 isozyme / 中华男科学杂志

Lactate dehydrogenase-C4 isozyme has been widely studied as the sperm-specific antigen in the research of the contraceptive vaccine. Developmental and testis-specific expression of the LDH-C gene requires mechanisms for activation in germ cells and repression in somatic cells. LDH-C promoter, several transcription factors and methylation of CpG dinucleotides have been proved of governing action on LDH-C gene transcription. The strategy is to induce antibodies in the female reproductive tract against LDH-C antigens at a sufficient level to block fertilization. Chemically modified LDH-C4 offers a potential application in the induction of infertility of homologous species in marked contrast to native LDH-C4. In addition, advances are being made in researches on the male contraceptive vaccine and synthetic peptide immunocontraceptive.