Objective:To explore the role of parental origin verification in chromosomal microarray analysis (CMA) on the determination of the clinical significance of copy number variations (CNVs).Methods:This retrospective study collected clinical information from 73 core families who underwent prenatal diagnosis at Peking University First Hospital from November 2017 to December 2019. Indications for prenatal diagnosis included ultrasound abnormality in 54 cases (including 12 with thickened nuchal translucency (≥2.5 mm), four with fetal growth restriction, seven with abnormal pregnancy history, and 31 with isolated ultrasound abnormality), NIPT indicated high-risk in four cases, advanced age in nine cases, abnormal pregnancy history alone in three cases, intrauterine death in two cases and one with maternal mental retardation. Genomic DNA of amniotic fluid sample, chorionic villi, cord blood, fetal tissues, and fetal heart blood were extracted using genomic DNA extraction kit. The CNVs of prenatal samples in 73 subjects were analyzed using array-based comparative genomic hybridization (array-CGH) analysis and single nucleotide polymorphism array (SNP-array). Peripheral blood DNA of the couples, and relevant families if necessary, were collected and analyzed in the same way. The results of parental origin detection in CMA were summarized.Results:A total of 76 CNVs were detected in these 73 samples, out of which nine were pathogenic and parental origin detection revealed that six were de novo, two were maternally, and one was paternally inherited; six CNVs were likely pathogenic, including three de novo, two maternally inherited and one paternally inherited; 20 CNVs were variants of uncertain significance, including five paternally inherited, three maternally inherited and 12 de novo; 41 CNVs were likely benign, among which 38 were inherited from parents with normal phenotype. Conclusions:Parental origin verification plays an important role in explaining the clinical significance of detected fetal CNVs and thereby can help to analyze its clinical effect and reproductive risk.

Objective To observe the relationship of IL-10 gene single nucleotide polymorphism and the susceptibility to ALL. Methods The bone marrow and peripheral blood samples from 115 ALL patients and 323 healthy controls were collected in Peking University First Hospital and Beijing Dao-pei Hospital from January 2007 to December 2009. The DNA were extracted from all samples. The primers of -819C/T and -592A/C in the promoter region of IL-10 gene were designed for the PCR. The restrictive fragment length polymorphism of IL-10 gene was analyzed by using restrictive enzyme Msl Ⅰ and HpyCH4 Ⅲ.Sequencing was done in part of these samples to confirm the results of PCR. The differences of genotypes and allele ratio of -819 and -592 sites were analyzed between the ALL patients and healthy controls. Real-time quantitative PCR was performed to detect the EB virus (EBV) infection and the expression of BCR/ABL fusion gene. The differences of genotypes and allele ratio of -819 and -592 sites were analyzed between the positive and negative group. Results The genotype ratios of -819CC, -819TT, - 819CT, -592AA,- 592CC and - 592AC were 14. 8% ( 17/115 ), 45.2% ( 52/115 ), 40. 0% ( 46/115 ), 43.5% ( 50/115 ),16. 5% ( 19/115 ), 40. 0% ( 46/115 ) in ALL patients, and were 9. 9% ( 32/323 ), 16. 4% ( 53/323 ),73.7% ( 238/323 ), 11.8% ( 38/323 ), 15.5% ( 50/323 ), 72. 8% ( 235/323 ) in the healthy controls,respectively. The genotypes of -819 and -592 sites had statistically significant differences between the two groups(x2 values were 46.000 and 54.550, all P ＜ 0. 05 ). The allele ratio of -819T and -592A were (65.2%, 150/230) and (63.5%, 146/230) in ALL patients, while they were 53.5% (344/646) and 48. 1% (311/646)in the healthy controls. There were statistically significant differences between the two groups (x2 values were 9. 877 and 15.986, all P ＜ 0. 05 ). The EBV DNA were detected in 42 ALL patients,among which 22 were positive and 20 were negative. The genotype ratios of -819CC, -819TT, -819CT,-592AA, - 592CC, - 592AC in EBV positive group were 9. 1% ( 2/22 ), 40. 9% ( 9/22 ), 50. 0%(11/22) ,31.8% ( 7/22 ), 13.6% ( 3/22 ), 54. 5% ( 12/22 ), while they were 35.0% ( 7/20 ), 45.0%(9/20) ,20. 0% (4/20) ,35.0% (7/20) ,45.0% (9/20) ,20. 0% (4/20) in the EBV negative group. The genotypes of -819 and -592 sites showed no statistical differences between the two groups( all P ＞ 0. 05 ).The BCR/ABL fusion gene were detected in 36 ALL patients, among which 20 were positive and 16 were negative. The genotype ratios of - 819CC, - 819TT, - 819CT, - 592AA, - 592CC, - 592AC in BCR/ABL positive group were 0% (0/20) ,45.0% (9/20) ,55.0% ( 11/20), 45. 0% (9/20) ,5.0% (1/20) ,50. 0%( 10/20), while they were 18. 8% ( 3/16 ), 50. 0% ( 8/16), 31.3% ( 5/16 ), 50. 0% ( 8/16 ), 18. 8%(3/16), 31.3 % (5/16)in the BCR/ABL negative group. The genotypes of -819 and -592 sites showed no statistical differences between the two groups ( all P ＞ 0. 05 ). Conclusion The population with - 819TT and - 592AA genotype of IL-10 gene shows susceptibility to ALL.

Objective To detect the proteins structure encoded by COL4A4 gene with different missense mutations of thin basement membrane nephropathy (TBMN) and to analyze the effect of gene mutation on the secondary structure of α4 (Ⅳ) chain and its association with phenotype. Methods A COL4A4-linked TBMN patient with FSGS by a missense mutation (g. 1214G>A resulting in p. G405E) diagnosed by clinical manifestations, family history and renal biopsy examination, as well as two controls (one healthy, one pure TBMN carrying a g. 1550G>A mutation resulting in p. G448S) were enrolled in this study. The fragments of cDNA with the two mutations and that of corresponding cDNA from the healthy control were expressed in E. coll. The secondary structures of recombinant polypeptides were analyzed by circular dichroism (CD) spectroscopy. Results CD spectra of healthy control exhibited a negative peak near 208 nm whereas that of TBMN patient with FSGS exhibited a negative peak near 220 nm. Furthermore, the magnitude of the negative peak of this patient decreased as compared with that of healthy control. CD spectra of pure TBMN control was slightly changed with the negative peak remaining near 208 run and the magnitude slightly decreased as compared with that of healthy control. In addition, the secondary structure of pelypeptide from healthy control was composed of about 1/4 α-helix and 1/4 β-sheet, whereas that from the patient presented about 1/3 α-helix without any β-sheet. The secondary structure of polypeptide from pure TBMN control was almost the same as the healthy control, except a shght reduction of α-helix and a slight increase of β-sheet. Conclusions Although the glycine substitutions exists in the nearby domain of α4 (Ⅳ)chain, the TBMN patient complicating FSGS with severe phenotype and g. 1214G>A mutation and the pure TBMN control with the mild phenotype and g. 1550G>A mutation are revealed with different secondary structures of α4 (Ⅳ)chain. Moreover, the secondary structure change of α4 (Ⅳ) chain is consistent with their corresponding phenotype severity.

Objective To analyze nucleophosmin (NPM1) gene mutations in exon 12 in patients with acute myeloid leukemia (AML) and evaluate the clinical appliance of three methods which are frequently used for detecting gene mutation. Methods Genomic DNA from bone marrow of 54 AML patients was detected by PCR for NPM1 exon 12 and screened by PCR-capillary electrophoresis, denature high-performance liquid chromatography (DHPLC) and direct sequencing separately. FLT3-ITD (FMS-like tyrosine kinease internal tandem duplication) was detected by agarose gel electrophoresis and PCR-capillary electrophoresis. Results Seven AML sample harbored NPM1 gene mutations. Five of them were the most common mutation, known as type A (an insertion of a TCTG tetranucleotide at position 960 bp). One of them was type D (an insertion of a CCTG tetranuclectide at position 960 bp). The new variant was a deletion of a TGGCAGTG sequence at 958 bp and insertion of a GCCCGCGGTTTA sequence instead. The detection ratio of the three methods was all 100% and capillary electrophoresis was more rapid, reliable and easier than the other two methods. Moreover it could detect FLT3-ITD simultaneously. The resolving power of DHPLC was affected by many factors. The direct sequencing method was tedious and the heterozygous sequence might be misread. Conclusions There is a new mutation at position 958 bp with a 12-nucleotide insertion and substitution. PCR-capillary electrophoresis is convenient to screen NPM1 mutations of AML in clinical practice.

Objective To explore possible impact of endogenous hydrogen sulfide(H2S) on connective tissue growth factor(CTGF) expression in rat pulmonary artery with high pulmonary blood flow.Methods Thirty-two male SD rats,weighing 120～140 g,were randomly divided into 4 groups:shunt group,shunt+PPG group,sham group and sham+PPG group.After 4 weeks of experiment,Rat lung tissue H2S content was determined by a modified sulfide electrode method.Plasma ET-1 concentration was detected by radioimmunoactivity,and lung tissue ET-1 mRNA expression of rat was determined by quantitative competitive reverse transcriptional polymerase chain reaction(RT-PCR).Pulmonary artery connective tissue growth factor(CTGF) protein expression of rats was investigated by immunohistochemistry.Results After 4 weeks of experiment,lung tissue H2S content plasma ET-1,lung tissue ET-1 mRNA and CTGF expression increased significantly in rats of shunt group as compared with that of sham group(P

Objective To explore the changing regularity of nitric oxide synthase(nNOS) in recurrent febrile seizures (FS), and the influence of NOS/NO on brain damage induced by recurrent FS.Methods FS rats were induced in a bath of warm water.The ex-periments were divided into 2 groups. The contents of nNOS cDNA in the first group was measured by quantitative RT-PCR and the contents of nNOS protein was measured by Western blot.The mtensity , latency, duration and rectal temperature of the seizure in rats in the second group were recorded. Morphologic changes of hippocampal neurons were observed with HE stain.Results Alter recur-rent FS, the expression of nNOS mRNA in hippocampus was significantly inereased compared with those in control group and hyper-thermia group, associated with an increase of nNOS protein.With the increase of seizure number,thert were changes of seizure latency and gradually prolonged trend of the seizure duration. By using the inhibitor of NOS, the seizure latency was gradually prolonged and the prolonged trend of the seizure duration was significantly decreased than that in FS group.There was no significantly difference of seizure intensity and rectal temperature between 2 groups.After recurrent FS, histological changes of hippocampal neurons could be seen under light microscope.The inhibitor alleviated nearonal injury.Conclusions Recurrent FS can induce nNOS gent expression.The NOS/NO system may be involved in the development of brain damage induced recurrent FS.

T mutation resulting in p.G1015V from an X linked Alport patient, and that of corresponding cDNA from a control were expressed in E.coli. The recombinant and mutant polypeptide was a fragment of COL4A5 , containing 158 amino acid residues with a glycine to valine substitution mutation in it. The secondary structure of the two recombinant proteins was analyzed using circular dichroism(CD) spectroscopy. Results: CD spectra of the control exhibited a negative peak near 200 nm whereas that of the patient exhibited a negative peak near 220 nm. The magnitude of the negative peak of the patient decreased as compared with that of the control. Furthermore, secondary structure of the control polypeptide was mainly composed of ? sheet and random coil without ? helix, whereas that of the patient presented 12.9% ? helix. Conclusion: Not only local structure of the substitution site but also folding kinetics of the entire ?5 chain may be changed due to Gly→Val substitution in Alport syndrome. We speculate that the abnormally folded polypeptide chain may not be assembled into the triple helix and the network of type Ⅳ collagen, or may be assembled into loosen triple helix then degraded easily, resulting in the pathognomonic ultrastructural changes of the glomerular basement membrane.

Objective To detect the activity of transglutaminase1(TGM1)and gene mutation in a family with lamellar ichthyosis.Methods Immunohistochemistry technique was used to detect the activity of transglutaminase1.Complete encoding sequences of TGM1gene were analyzed in this family by using PCR-DNA sequencing.Results No activity of transglutaminase1was detected in the proband's skin.A nonsense mutation of C604T located in exon4of TGM1gene was identified by PCR-DNA sequencing,which caused a premature termination of Q202X and a defective polypeptide truncated by615amino acids in C-terminus.A heterozygous C604T mutation was carried by both of the proband' s parents.Conclusions The proband of lamellar ichthyosis in this family shows loss of transglutaminase1activity,which is resulted from a truncated transglutaminase1coded by the homozygous mutant TGM1gene.

Objective To map the specific gene responsible for primary erythromelalgia and identify gene mutations in a Chinese family and one sporadic patient with primary erythromelalgia. Methods Geno-mic DNA was extracted from peripheral lymphocytes of the family members of the pedigree and the sporadic patient. Scanning the genes on chromosome 2q that had been identified was performed by using 6 microsatellite markers for the family members with primary erythromelalgia. Then linkage analysis and haplotype analysis were conducted. All exons of SCN9A gene were analyzed by PCR-DNA sequencing. The mutation identification was also confirmed by restriction fragment length polymorphism(RFLP). Results A maximum 2-point LOD score of 2.11 was found at a recombination fraction (? = 0.00) with markers D2S2370 and D2S2330. Recombination events were detected by markers D2S1353 and D2S2345 in this family by the haplotype analysis. There were two missense heterozygous point mutations in the 15th exon of SCN9A gene both in the family(T2573A) and the sporadic patient(T2543C), leading to the substitution of the amino acid leucine to histidine(L858H) and isoleucine to threonine(I848T), respectively. The above mutations were not found in 400 normal alleles. Conclusion It is proved that primary erythromelalgia is caused by mutations in SCN9A gene.

Objectives To report a generalized atrophic benign epidermolysis bullosa family,identify the deficient protein and related pathogenic gene mutation. Methods The diagnosis was confirmed based on clinical manifestations and necessary examinations. Electron microscopy and immunofluorescent staining were used to detect the deficient protein. The pathogenic gene mutation was identified by PCR amplification of ge-nomic DNA with primers targeting the flanking introns, followed by direct automated sequencing. Results In the family, the affected individuals were homozygous for a novel 4-bp deletion in COL17A1, 3897delATCT, which resulted in a downstream premature termination codon. Conclusions 3897delATCT of COL17A1 is the pathogenic gene mutation in the patients and probably results in nonsense-mediated mRNA decay and abrogation of type XⅦ collagen synthesis, as documented in the literature.