Preliminary study on the clinical value of noninvasive prenatal testing of fetal chromosomal copy number variations / 中国实用妇科与产科杂志

OBJECTIVE: To explore the clinical value of non-invasive prenatal testing(NIPT)for screening fetal chromosomal copy number variations(CNVs) and microdeletion/microduplication syndromes(MDs).METHODS: Retrospective analysis was made in the 10 005 women who received NIPT during the first trimester(15-20+ 6 weeks)from January,2012 to July,2017,at First People's Hospital of Yunnan Province,Department of Genetic Diagnosis Center.Among them 32 pregnant women were indicated fetal CNVs,25 of 32 pregnant women selected interventional prenatal diagnosis.Statistical analysis was made on the amniotic fluid/cord blood chromosome G band karyotype and high-throughput sequencing(NGS)genome copy number analysis was made,and relevant CNVs were searched and analyzed in the corresponding database;the consistency of CNVs found in NIPT with interventional prenatal diagnosis was statistically analyzed.RESULTS: During the second trimester(15-20+ 6 weeks),in the 10 005 pregnant women who received NIPT testing 32 cases were shown to have high risks of fetal CNVs,and the screening positive rate was 0.32%(32/10 005).In 25 high risk pregnant women who accepted invasive prenatal diagnosis via informed choice,14 women wereconfirmed as fetal CNVs,the positive predictive value(PPV)of NIPT being 56%(14/25),including 9 cases of microdeletion and 5 cases of microduplication.The sizes were between 587.75 kb and 36.05 Mb.The size and the start and end positions of CNVs found by NIPT were similar to those of fetal DNA samples detected by NGS.Among 14 cases of fetal CNVs,11 cases were identified as MDs,3 cases as unknown clinical significance.In 11 cases of MDs,8 cases were observed fetal chromosome structure abnormalities by karyotype analysis,10 cases were confirmed as de novo abbreviations,and 2 cases as originated from paternal same MD.After genetic counseling,10 pregnant women in 11 cases of MDs chose informed terminations,and one case chose continuing pregnancy.CONCLUSION: As a high-precision screening method,NIPT is expected to be an effective mean to screen for fetal CNVs,which can be used to detect highrisk chromosome microdeletion and microduplication CNVs of larger segments.High risk cases of fetal CNVs found by NIPT require invasive prenatal diagnosis for validation.

Association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy / 中国当代儿科杂志

OBJECTIVE@#To study the association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy (SMA).@*METHODS@#A total of 45 children with SMA were enrolled. Multiplex ligation-dependent probe amplification was used to measure the gene copy numbers of SMN1 and SMN2. The association of copy number of SMN1 and SMN2 with clinical phenotypes was analyzed.@*RESULTS@#Of the 45 children with SMA, 42 (93%) had a homozygous deletion of SMN1 exons 7 and 8, and 3 (7%) had a deletion of SMN1 exon 7 alone. No association was found between SMA clinical types and the deletion types of SMN1 exons 7 and 8 (P>0.05). There was a significant difference in the distribution of SMN2 gene copy numbers between the children with SMA and the healthy children (P<0.05). The children with SMA usually had two or three copies of SMN2 gene, while the healthy children usually had one or two copies of SMN2 gene. There was a significant difference in the distribution of SMN2 copy numbers among the children with different SMA clinical types (P<0.05). The children with two copies of SMN2 gene had a significantly lower age of onset than those with three or four copies. Most of the children with type I SMA had two or three copies of SMN2 gene. Most of the children with type II SMA had three copies of SMN2 gene. Most of the children with type III SMA had three or four copies of SMN2 gene. Children with a higher copy number of SMN2 gene tended to have an older age of onset and better motor function and clinical outcome, and there was a significant association between SMN2 gene copy number and clinical outcome (P<0.05).@*CONCLUSIONS@#The SMN2 gene can reduce the severity of SMA via the dosage compensation effect. SMN2 copy number is associated with the phenotype of SMA, and therefore, it can be used to predict disease severity.

Analysis of treatment efficacy for congenital hypothyroidism in some regions of Yunnan Province, China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To observe the effects of initial doses and treatment timing of levothyroxine (L-T4) on the clinical efficacy in children with congenital hypothyroidism (CH).</p><p><b>METHODS</b>This study included 98 children who had an abnormal level of thyroid stimulating hormone (TSH) in neonatal screening in four regions of Yunnan Province and who finally had a confirmed diagnosis of CH. They received treatment with L-T4 and were divided into standard dose group (10-15 μg/kg per day) and low dose group (<10 μg/kg per day) by the therapeutic dose of L-T4. Meanwhile, these patients were also classified into two treatment groups based on the starting time of L-T4 treatment, namely under 2 months old group and more than 2 months old group. The thyroid function and physical and neural development were examined before and after treatment.</p><p><b>RESULTS</b>Compared with the low dose group, the standard dose group had a significantly lower TSH level and a significantly higher free thyroxine (FT4) level at 2 weeks after treatment (P<0.05). There were no significant differences in TSH and FT4 levels at other time points after treatment between the standard and low dose groups (P>0.05). The physical and neural development were not significantly different between the two dose groups before and at all time points after treatment (P>0.05). At all time points after treatment, the levels of TSH and FT4 and physical development were not significantly different between the different starting time groups (P>0.05). However, the Gesell score was significantly higher in the under 2 months old group than in the more than 2 months old group at all time points after treatment (P<0.05).</p><p><b>CONCLUSIONS</b>The standard dose group has a better treatment outcome than the low dose group, whereas the symptoms of hyperthyroidism deserve close attention. The treatment timing is vital to the neurodevelopment of children with CH. Once diagnosed, the patients should receive treatments immediately.</p>

Gene Analysis of Thalassemia in Han and Dai Ethnic Childbearing-aged Population of Chinese Yunnan Province / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the common mutation spectrum of α- and β-thalassemia in Yunnan childbearing-aged population.</p><p><b>METHODS</b>The common mutation types of α- or β-globin genes were detected by multiple Gap-PCR and the PCR-reversed dot blotting, and the unknown mutation types were determined by DNA sequencing in DNA samples of hypochromic microcytic anemia patients and carriers who were confirmed to be positive by serologic screaning, then the mutation types of globin in Yunnan population were analyzed statistically.</p><p><b>RESULTS</b>A total of 40 kinds of mutation types were detected in 685 detected persons, among them the 3 commonest mutation types of α-globin genes were --(SEA)/αα (49.09%), -α(3.7)/αα (36.67%) and α(CS)α/αα (8.79%), the 3 commonest genetypes of β-globin gene were CD26(GAG>AAG)/N (43.78%), CD41-42(-CTTT)/N (20.1%) and CD17(AAG>TAG)/N (18.9%). There were 348 Han and 212 Dai ethnic persons in 685 cases, but their mutation of globin genes were different between these 2 ethnic groups. The results also showed that the gene mutation types were mostly concentrated in Dai ethnic individuals, since 28 of 38 detected α-β-thalassemia cases were Dai ethnic individuals.</p><p><b>CONCLUSION</b>The mutation spectrums of α- and β-globin genes in Yunnan childbearing-aged population are diverse and different from that in other areas of China.</p>

Gene Mutation Spectrum of β-Thalassemia in Dai Ethinic Population of Two Border Region in Chinese Yunnan Province / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the gene mutation spectrum of β-thalassemia in Dai ethnic population of 2 border region in Chinese Yunnan Province.</p><p><b>METHODS</b>The patients with β-thalassemia in Dai ethnic population of Dehong and Xishuangbanna autonamic prefecture were screened by using blood routine detection and capillary electrophoresis. The β-globin gene mutation in patients with β-thalassemia were detected by using PCR reverse dot-blot hybridization (PCR-RDB), the constitutive rate of gene mutation in patients with β-thalassemia of Dai ethnic population in two border regions was analyzed and compared.</p><p><b>RESULTS</b>A total of 186 patients with gene mutation of β-thalassemia were confirmed. Among them, 10 gene mutation were found, and the 5 main gene mutations were CD26 (62.56%), CD41-42 (18.97%), CD17 (14.36%), CD71-72 (2.05%) and IVS-II-654 (1.54%). Among Dai ethinic population in Dehong region, 4 gene mutations were found including CD26 (80.31%), CD17 (11.02%), CD41-42 (6.30%) and CD71-72 (2.36%). Among Dai ethinic population in Xishuangbanna region, 6 gene mutations were found, out of them the more common gene mutations were CD41-42 (42.64%), CD26 (29.41%) and CD17 (20.59%).</p><p><b>CONCLUSION</b>The gene mutations of β-thalassemia in Dai ethinic population of Yunnan province has been confirmed to be more genetic heterogenicity, the spectrums of β-thalassemia mutations in Dai ethinic population of different regions were significant different.</p>

Analysis of neonatal screening results for congenital hypothyroidism in parts of Yunnan Province, China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To summarize and analyze neonatal screening results for congenital hypothyroidism (CH) in parts of Yunnan Province, China.</p><p><b>METHODS</b>A total of 236 218 newborns (121 463 males and 114 755 females) who were born in Zhaotong City, Qujing City, Lijiang City, and Diqing Tibetan Autonomous Prefecture of Yunnan Province, China, between July 2012 and April 2014 were screened for CH. The original blood smear was re-tested if the thyroid stimulating hormone (TSH) level in heel blood was ≥8 μIU/L in the initial screening. The newborns with positive TSH results were called back for further diagnosis by measuring blood TSH and free thyroxine (FT4) levels.</p><p><b>RESULTS</b>Among 236 218 newborns, the pass rate of blood smears, re-acquisition rate of unqualified blood smears, and recall rate of suspected cases were 96.67%, 81.75%, and 73.02%, respectively. Sixty-six cases of CH were confirmed, among which 36 were male infants and 30 were female infants (P>0.05). The incidence rate of CH was 1/3 579, which was significantly lower than the national average rate (1/2 034; P<0.01). The gestational age of CH newborns was mostly between 37 to 42 weeks, and only 3% were born at a gestational age of >42 weeks. Most of the CH newborns had normal birth weight. The CH newborns with a body length of <50 cm accounted for 32%.</p><p><b>CONCLUSIONS</b>The incidence of CH in Yunnan Province is lower than the national average. There are no specific clinical features in CH newborns. The neonatal screening in Yunnan Province needs further improvement.</p>

Association of 1233A/G polymorphism of angiopoietin-2 gene with type 2 diabetes mellitus and diabetic nephropathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association between single nucleotide polymorphisms (SNP) of angiopoietin-2 (Ang-2) gene and type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN).</p><p><b>METHODS</b>Genotype and allele frequency of Ang-2 were detected by amplification refractory mutation system-PCR(ARMS-PCR) in 221 cases with T2DM and 104 normal controls. Monocyte chemoattractant protein-1(MCP-1) was measured by ELISA. DN patients were divided into three groups according to urinary albumin excretion rates (UAER), i.e. DN0: UAER < 30 mg/24 h, DN1: UAER 30-300 mg/24 h and DN2: UAER > 300 mg/24 h.</p><p><b>RESULTS</b>Statistics showed: (1) Genotype frequencies and allele frequencies in Ang-2 1233A/G had significant difference but not Ang-2 759T/G and 1078A/G; (2) Comparing with those with genotype AA, the relative risk of genotype (AG+ GG) suffered from T2DM and DN were 2.265 fold (OR= 2.265, 95% CI: 1.223-1.402, P= 0.031), 1.789 fold (OR= 1.789, 95% CI: 0.889-1.021, P= 0.012), respectively; (3) The onset of DN was related to Ang-2 1233A/G allele G (r= 1.321, OR= 1.427, 95% CI: 2.324-4.177, P= 0.034).</p><p><b>CONCLUSION</b>Ang-2 1233A/G polymorphism may be associated with T2DM and involved in onset and development of DN.</p>

Preimplantation genetic diagnosis for a patient with Robertsonian translocation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the feasibility and risk of preimplantation genetic diagnosis (PGD) for screening normal offspring of Robertsonian translocation carriers.</p><p><b>METHODS</b>This case was clinically diagnosed as primary infertility for 6 years; the husband was found to have chromosome der (13;14) (q10;q10) and oligozoospermia. For the solution of the couple's problem, controlled ovarian hyperstimulation (COH) and intracytoplasmic sperm injection (ICSI) were performed to obtain embryos. The embryos were drilled in zona by acidified Tyrode's solution at 6-8 cell stage (day 3 post-fertilization) and a single blastomere was removed from each embryo. All blastomeres were analyzed by fluorescence in situ hybridization (FISH) using the double color probes LSI 13q labeled by SpectrumOrange and Tel 14q labeled by SpectrumGreen. The embryos biopsied were cultured at once and the normal ones selected were transferred the next day. Prenatal diagnostic techniques were used to detect the karyotype of fetus at 18 weeks of gestation.</p><p><b>RESULTS</b>Unbalanced, normal or balanced, and unclear embryos were separated. The couple obtained 50a (4/8)normal or balanced,and 37.5a (3/8)unbalanced, and 12.5a (1/8) unclear embryos. A singleton pregnancy followed, and the karyotype of the fetus (46,XY) was detected by prenatal diagnostic techniques.</p><p><b>CONCLUSION</b>PGD is useful for screening out unbalanced embryos and is very valuable for solving the reproductive problem of Robertsonian translocation carriers and for avoiding fetal beings with severe disorders.</p>

Detection of chromosome 8 anomalies in ovarian carcinoma by fluorescence in situ hybridization / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the relationship between chromosomal anomalies and the pathogenesis, development and prognosis of ovarian carcinoma.</p><p><b>METHODS</b>Thirty-six specimens of ovarian carcinoma (n=12), ovarian benign tumor (n=12), and normal ovary (n=12) were examined by fluorescence in situ hybridization (FISH).</p><p><b>RESULTS</b>Twelve cases of mutations, including trisomy 8, monosomy 8 or tetraploid 8 chromosomal anomalies, were found in the group of ovarian carcinoma, making up 100% (12/12). Three cases of trisomy 8 chromosomal anomalies were found in the group of ovarian benign tumor, accounting for 25% (3/12). No anomaly was found in the normal group. There were significant differences between the three groups, P<0.001.</p><p><b>CONCLUSION</b>The above anomalies of chromosome 8 are significantly associated with the pathogenesis and development of ovarian carcinoma. The anomalies may occur in the early stage of the carcinoma, and may be significantly associated with the pathological differentiation and clinical stage of the case.</p>