Expression of Nitric Oxide Synthase Isoenzyme in Lung Tissue of Smokers with and without Chronic Obstructive Pulmonary Disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>It has been demonstrated that only 10%-20% cigarette smokers finally suffer chronic obstructive pulmonary disease (COPD). The underlying mechanism of development remains uncertain so far. Nitric oxide (NO) has been found to be closely associated with the pathogenesis of COPD, the alteration of NO synthase (NOS) expression need to be revealed. The study aimed to investigate the alterations of NOS isoforms expressions between smokers with and without COPD, which might be helpful for identifying the susceptibility of smokers developing into COPD.</p><p><b>METHODS</b>Peripheral lung tissues were obtained from 10 nonsmoker control subjects, 15 non-COPD smokers, and 15 smokers with COPD. Neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS) mRNA and protein levels were measured in each sample by using real-time polymerase chain reaction and Western blotting.</p><p><b>RESULTS</b>INOS mRNA was significantly increased in patients with COPD compared with nonsmokers and smokers with normal lung function (P < 0.001, P = 0.001, respectively). iNOS protein was also higher in COPD patients than nonsmokers and smokers with normal lung function (P < 0.01 and P = 0.01, respectively). However, expressions of nNOS and eNOS did not differ among nonsmokers, smokers with and without COPD. Furthermore, there was a negative correlation between iNOS protein level and lung function parameters forced expiratory volume in 1 s (FEV₁) (% predicted) (r = -0.549, P = 0.001) and FEV₁/forced vital capacity (%, r = -0.535, P = 0.001).</p><p><b>CONCLUSIONS</b>The expression of iNOS significantly increased in smokers with COPD compared with that in nonsmokers or smokers without COPD. The results suggest that iNOS might be involved in the pathogenesis of COPD, and may be a potential marker to identify the smokers who have more liability to suffer COPD.</p>

A pilot study on spinal muscular atrophy carrier screening in Shanghai region using real-time PCR / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To develop a screening program for spinal muscular atrophy (SMA) carriers, and to assess the carrier frequency and detection rate in Shanghai region.</p><p><b>METHODS</b>Quantitative analysis of the SMN1 gene by real-time PCR was developed using specimens from 15 SMA patients and 76 SMA parents from 38 affected nuclear families. A pilot screening was carried out for 1741 asymptomatic pregnant women. Frequencies of SMN1 alleles were determined with the Hardy-Weinberg equilibrium.</p><p><b>RESULTS</b>Forty five out of the 1741 women were identified as SMA carriers by the presence of single copy of SMN1. The frequencies of no copy, 1 copy, 2 copy and 3 copy alleles were 1.37 U+00D7 10-2, 9.45 U+00D7 10-1, 2.80 U+00D7 10-2 and 1.27 U+00D7 10-2, respectively. The adjusted SMA carrier frequency was 1:35 with a detection rate of 94.49%. For those with a negative screening result, individuals with 3 copies carried a higher residual risk.</p><p><b>CONCLUSION</b>The incidence of SMA carriers in Shanghai region is similar with that in Caucasian populations. Carrier screening has high detection efficiency. An effort should be made to further distinguish SMN1 gene copy numbers for those with more than 2 copies, since accurate determination of 2 and 3 copy allele frequencies is essential for post-screening genetic consulting.</p>

Molecular and cytogenetic characterization of six 46, XX males due to translocations between the short arms of X and Y chromosomes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To characterize molecular and cytogenetic abnormalities in six 46, XX males, and to investigate the clinical manifestations and underlying mechanisms in such patients.</p><p><b>METHODS</b>Clinical data of six XX male patients were collected. Karyotyping, multiple polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) were utilized to detect and locate the sex determining region (SRY) gene.</p><p><b>RESULTS</b>PCR and FISH showed that all patients were SRY-positive XX males. All patients have their SRY gene located at the tip of derivative X chromosomes, which have resulted from translocation between short arms of X and Y chromosomes. High resolution karyotyping at 550-750 band level has revealed that the translocation breakpoints were at Xp22.33 and Yp11.2 in three patients. In the remaining patients, the breakpoints were either at Xp22.32 and Yp11.31 or Xp22.31 and Yp11.2. The breakpoints at Xp22.32, Xp22.31 and Yp11.31 were rarely reported. Genotype-phenotype correlation analysis indicated that the clinical manifestations were age-specific. Four adult patients have come to clinical attention due to infertility, with typical features including azoospermia and testis dysgenesis, whereas poorly developed secondary sexual characteristics and short stature were main complaints of adolescence patients, and short stature was the sole symptom in a child patient.</p><p><b>CONCLUSION</b>Combined karyotyping, PCR and FISH are important for the analysis of XX males. Particularly, high resolution karyotyping is valuable for the refinement of chromosome breakpoints and detailed analysis of genotype-phenotype correlation.</p>

Optimization of polymerase chain reaction assay combined with capillary electrophoresis to detect the pre- and full mutation of FMR1 gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To develop an efficient, high resolution PCR assay suitable for detection of the (CGG)n repeats of the fragile X mental retardation 1 (FMR1) gene by optimizing the PCR system in combination with capillary electrophoresis.</p><p><b>METHODS</b>Three standard samples and twelve samples that were verified by Southern blot analysis including both male and female in the normal, pre- and full mutation range were used in this study to evaluate the enhanced PCR system. All amplicons were electrophoresed by agarose, polyacrylamide and capillary electrophoresis to compare the results.</p><p><b>RESULTS</b>The enhanced PCR assay developed in this study was able to detect a full mutation with (CGG)n being larger than 260 repeats in a male. An expanded pre-mutation allele with (CGG)n as large as 183 repeats in a female was also amplified. The capillary electrophoresis method used in this study was able to distinguish two alleles with 1 CGG repeat difference and the results were reproducible.</p><p><b>CONCLUSION</b>A high resolution PCR assay is developed, which is much more efficient than the general PCR systems. It is suitable for the clinical screening of FMR1 gene and will greatly reduce the number of Southern blot analysis needed in clinical application.</p>

Two cases of partial trisomy 8p derived from paternal reciprocal translocation or maternal insertion translocation: clinical features and genetic abnormalities / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the origin of aberrant chromosomes involving the short arm of chromosome 8 in two mentally retarded children, and to correlate the karyotype with abnormal phenotype.</p><p><b>METHODS</b>Routine G-banding was performed to analyze the karyotypes of the two patients and their parents, and array comparative genomic hybridization (array CGH) was used for the first patient for fine mapping of the aberrant region.</p><p><b>RESULTS</b>The first patient presented with only mental retardation. The father had normal karyotype. The mother had an apparent insertion translocation involving chromosomes 8 and 3 [46, XX, inv ins (3; 8) (q25.3; p23.1p11.2)], the karyotype of the child was ascertained as 46, XX, der(3) inv ins (3; 8)(q25.3; p23.1p11.2). Array CGH finely mapped the duplication to 8p11.21-8p22, a 26.9 Mb region. The other patient presented with mental retardation, craniofacial defects, congenital heart disease and minor skeletal abnormality. The mother had normal karyotype. The father had an apparently balanced translocation involving chromosome 8p and 11q, the karyotype was 46, XY, t(8; 11)(p11.2; q25). The karyotype of the child was then ascertained as 46, XX, der(11)t(8; 11)(p11.2; q25).</p><p><b>CONCLUSION</b>These results suggested that partial trisomy 8p was primary cause for the phenotypic abnormalities of the two patients, whereas a mild phenotypic effect was observed in patient 1. Parental karyotype analysis could help define the aberrant type and recurrent risk evaluation. In contract to routine karyotype analysis, aberrant regions could be mapped by array CGH with higher resolution and accuracy.</p>

A case with partial trisomy 7 (q34→qter) derived from a paternal reciprocal translocation t(7;14)(q34;q32) / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the origin of chromosomal aberrants in a mentally retarded children, and to correlate the karyotype with phenotype.</p><p><b>METHODS</b>Routine G-banding were performed to analyze the karyotype of the patient and her parents, and array comparative genomic hybridization (array CGH) were used for finely mapping the aberrant regions.</p><p><b>RESULTS</b>The mother had a normal karyotype. The father had an apparently balanced translocation involving chromosome 7q and 14q, the karyotype was 46, XX, t(7;14) (q34;q32), the karyotype of the child was then ascertained as 46, XX, der(14) t(7;14) (q34;q32.33) pat. Array CGH finely mapped the duplication to 7q34-qter, a 17.09 Mb region, and a very small associated deletion of distal chromosome 14 to 14q32.33-qter, a 2.27 Mb region. The patient presented some frequently seen features in partial trisomy 7q cases such as mental retardation, low birth weight, small nose, cleft palate, low-set ears and short neck.</p><p><b>CONCLUSION</b>This result suggested that partial trisomy 7q exert mainly phenotypic effect on the patient. Parental karyotype analysis could help define the aberrant type.</p>

Clinical application of multiplex ligation-dependent probe amplification for the detection exonic copy number alterations in the Dystrophin gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To clarify advantages and disadvantages of using multiplex ligation-dependent probe amplification (MLPA) for detecting exonic deletions and duplications of the Dystrophin gene, and to explore the appropriate management for single-exon abnormality detected by MLPA.</p><p><b>METHODS</b>MLPA were performed to detect exonic copy number changes in 70 Duchenne/Becker muscular dystrophy (DMD/BMD) patients diagnosed by clinical and histological findings. PCR, DNA sequencing and real-time PCR were applied to the samples in which MLPA indicated single-exon deletion or duplication.</p><p><b>RESULTS</b>Of all 70 patients, MLPA detected exonic deletions in 42 (60%), including 12 with single-exon deletion and one with ambiguous single-exon deletion. Exon duplications were found in 7 patients (10%), among which two were single-exon duplication. 21 patients showed normal results (30%). For the 12 patients with single-exon deletion, MLPA results were confirmed by PCR in 11. In one patient, a deletion of two nucleotides (c.4470-4471delAA) was found by sequencing. A novel two-nucleotide deletion (c.4746-4747delCT) was identified in the patient with the ambiguous single-exon deletion. For the two patients showed single-exon duplication, MLPA results were confirmed by real-time PCR.</p><p><b>CONCLUSION</b>MLPA should be the first choice in detecting Dystrophin gene exon deletions and duplications. Single-exon deletion/duplication resulted from MLPA should be further evaluated by other methods.</p>

Cytogenetic and molecular genetic study of a case with 8p inverted duplication deletion syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To define the origin and the precise location of the aberrant fragments on the short arm of the chromosome 8 in a mentally retarded boy, and to understand the mechanism, the characteristic clinical features and the recurrent risk associated with this abnormality.</p><p><b>METHODS</b>High-resolution chromosomal banding was performed to analyze the karyotype of the patient and his parents, array comparative genomic hybridization (array-CGH) was employed to investigate the precise location of the aberrant fragments, and quantitative real-time PCR was used to confirm the results.</p><p><b>RESULTS</b>The rearranged chromosome 8 in the patient was inverted and duplicated for region 8p11.2-p23.1, and deleted for region 8p23.1-pter. In between, a 5.70 Mb single copy region was present, which was delimited by the two olfactory receptor (OR) gene clusters.</p><p><b>CONCLUSION</b>This is a case of classic inv dup del(8p) syndrome, which is characterized by severe mental retardation, brain malformation and specific facial dysmorphism, and is induced by non-allelic homologous recombination (NAHR) between the OR genes on 8p23.1. Prenatal diagnosis should be performed to monitor the recurrent risk of inv dup del(8p), as well as the other three harmful consequences resulted from the same NAHR mechanism. To the best of our knowledge, this is the first case of inverted duplicated 8p syndrome identified in Mainland China.</p>