Objective To explore the characteristics and ecological risk assessment of heavy metals pollution in the fluvial sediment in Hengyang section of Xiang river.Methods The fluvial sediments in 18 sites in 10 sections of Hengyang section of Xiang river were collected for determination of heavy metals(Cu,Zn,As,Hg,Cd,Cr,Pb) in 2007.The accumulation levels of heavy metals in the fluvial sediment and their potential ecological risks were assessed by the Hankanson potential ecological risk(PER) factors method.Results The average potential ecological risk index of Cd in sediment of Xiang river was 352.1 with the highest ecological risk,the index of Hg was 272.1 with higher ecological risk,the index of Pb and As was 150.1 and 104.7 with high ecological risk,the index of Cr,Zn and Cu were all lower than 40 with low ecological risk.On the whole,the integrated pollution index of seven kinds of heavy metal was 913.4.Conclusion The fluvial sediment of Hengyang section of Xiang rive has been polluted by heavy metals in a certain degree and is characterized as a complex pollution situation with a higher ecological risk.

Objective To analyze iodine nutrition and its correlation with thyroid function in pregnant women.Methods A total of 295 pregnant women were enrolled from Jun.to Oct.2016,and detected for serum levels of thyroid stimulating hormone(TSH),free thyroxine(FT4) and thyroid-peroxidase antibody(TPOAb) by using electrochemiluminescence analysis,and for urinary iodine concentration(UIC) by cold digestion method according to iodine catalytic effect of arsenic-cerium.Results The median of UIC was 174.90 μg/L.The prevalence of iodine deficiency and iodine excess were 40.00% and 7.12% respectively.The prevalence of TPOAb positivity and thyroid dysfunction in the iodine deficiency group and iodine excess group were significantly higher than those of iodine proper group(P<0.05).The levels of TSH and FT4 of iodine excess group were significantly higher than those of iodine proper group(P<0.05).Conclusion The abnormality of iodine nutrition could be common in pregnant women.Monitoring of UIC and thyroid hormones should be highlighted.

Objective: To reveal the molecular epidemiologic characteristics of glucose-6-phosphate dehydrogenase (G6PD) gene and to evaluate based on the genetic analysis the newborn screening program performance and enzymatic diagnosis of G6PD deficiency in Guangzhou. Methods: G6PD enzyme activities were measured by quantitative fluorescence assay in dry blood spots of 16 319 newborns(8 725 males, 7 594 females) 3-7 days after birth in Guangzhou Newborn Center. They were born in Guangzhou form Oct. 1 to 20, 2016. The cutoff value of G6PD was less than 2.6 U/g Hb in dry blood spots. G6PD deficiency was diagnosed when G6PD<1 700 U/L or G6PD/6PGD<1 in red blood cells. Genetic analysis of G6PD gene was performed on the dry blood spot samples of 823 newborns (including positive 346, negative 477)with various levels of G6PD enzyme activities through fluorescence PCR melting curve analysis(FMCA) to detect 15 kinds of mutations reported to be common among Chinese.G6PD gene Sanger sequency was performed in seven highly suspicious patients with negative results by FMCA. Results: (1) Using the cutoff value of G6PD< 2.6 U/g Hb , a total of 687(4.2%) newborns showed positive screening results, including 560 (6.4%) males and 127(1.7%) females. (2) Among the newborns with positive screening results, 214 males and 122 females were randomly chosen for G6PD gene analysis. The results showed that 197 (92.1%) males were hemizygote and 108(88.6%) females were mutation carriers with one to four alleles. Among the newborns with negative screening results, 41 males with G6PD 2.6-2.8 U/g Hb and 436 females with G6PD 2.6-4.5 U/g Hb were chosen for genetic analysis.Mutations were detected in 5(12.2%)boys, and 226(51.8%) girls were carriers.G6PD gene Sanger sequency of seven highly suspicious patients showed that c.406C>T, c.551C>T, c.835A>T hemizygote were found in 3 male's samples, respectively. (3) The estimated prevalence of harboring mutation was 6.0% in males and 13.5% in females according to rates of mutation in samples with various levels of G6PD enzyme activities. Six common mutations were c.1388G>A、c.1376G>T, c.95A> G, c.871G>A, c.1024C>T, c.392G>T, accounting for 95.5% of detected alleles .(4) based on results of G6PD gene analysis, the newborn scereening of G6PD deficiency with cutoff value G6PD<2.6 U/g Hb yielded a positive predict value(PPV) of 93.5%, a false-positive rate of 0.5%, and a sensitivity of 99.0% for males. A PPV of 88.5%, a false-positive rate of 0.2% . The prevalence of severe type G6PD deficiency in females was about 1.5%. Compared with to genetic analysis, the sensitivity and PPV of G6PD activity assay in red blood cells were 95.5%, 97.2%, respectively. Conclusions The prevalence of G6PD deficiency in males was 6.0% in Guangzhou. Six mutations c.1388G>A, c.1376G>T, c.95A>G, c.871G>A, c.1024C>T, c.392G>T accounted for 95.5%. The cutoff value of G6PD<2.6 U/g Hb innewborn screening program and the criteria of biochemical diagnosis could accurately identify G6PD deficiency . Combined with biochemical and molecular analysis will improve the accuracy of diagnosis of G6PD deficiency and detect more heterozygous females.

Objective:To investigate the sensitivity of newborn screening for neonatal intrahepatic cholestasis caused by Citrin deficiency (NICCD) based on tandem mass spectrometry and the carrying rate of known pathogenic variants of SLC25A13 in Guangzhou population. Methods:A total of 124 250 neonates born in Guangzhou from January 1, 2015 to December 31, 2018 were performed newborn screening for NICCD by tandem mass spectrometry technology. SLC25 A13 gene mutation analysis was performed to diagnose patients with suspected NICCD.The carrying rate of known pathogenic variants of the SLC25 A13 gene in the whole exon sequencing results of 2 395 healthy children in Guangzhou was retrospective analyzed. Results:Among the 124 250 screened neonates, 31 cases were screened positive for NICCD and one of them was confirmed.Three false negative patients with NICCD were found in this cohort.NICCD screening sensitivity was 25%(1/4 cases). All of the four patients were homozygous for c. 851_854del of SLC25A13.Among 2 395 controls, 60 cases were detected heterozygous variant of SLC25A13, including 8 kinds of reported pathogenic variants.The carrying rate of pathogenic alleles was 1/40 (60/2 395 cases). The estimated prevalence of citrin deficiency was about 1/6 400.The most common variant was c. 851_854del (56.7%, 34/60 cases), and the second was c. 790G>A (23.3%, 14/60 cases). The controversial variant c. 2T>C was detected in 113 children with heterozygous and 2 cases with homozygous and the carrying rate of c. 2T>C was 1/20(117/2 395 cases). Conclusions:The carrying rate of pathogenic variants of SLC25A13 and the estimated prevalence of Citrin deficiency in Guangzhou population are high.The sensitivity of newborn screening for NICCD by tandem mass spectrometry is limited.Even if the negative results for screening of multiple genetic and metabolic diseases by tandem mass spectrometry, it is recommended to recheck blood for newborns or infants with delayed jaundice to avoid missed diagnosis.

Objective:To evaluate and improve the performance of the newborn screening program for primary carnitine deficiency (PCD) based on tandem mass spectrometry and to investigate the incidence of PCD and molecular characteristics of SLC22A5 gene in Guangzhou.Methods:A total of 200 180 neonates born in Guangzhou from 2015 to 2019 were enrolled into the newborn screening program for PCD by tandem mass spectrometry at Guangzhou Newborn Screening Center. The positive results of screening for PCD was defined as free carnitine (C0) less than 10 μmol/L with decreased acylcarnitine species in dried blood spots of three to seven days after birth. Screen-positive newborns and their mothers were recalled for another blood spot sample. The diagnosis was confirmed based on decreased levels of C0 and acylcarnitine species in recalled blood spots and genetic analysis in SLC22A5 gene sequencing. The utility of using the sum of propionylcarnitine and palmitoylcarnitine (C3+C16) as a biomarker for acylcarnitine species in newborn screening was retrospectively evaluated. The levels of C0 and (C3+C16) at first screening were compared between newborns with PCD and newborns born to mothers with PCD by independent t test. The variant spectrum and known pathogenic variants carrier rate of SLC22A5 in 2 395 healthy children in Guangzhou Women and Children′s Medical Center through whole exon sequencing were analyzed. Results:Among 200 180 neonates, 239 (0.12%) cases were screen-positive for PCD. A total of 37 patients including 15 newborns and 22 mothers had confirmed PCD. The incidence of PCD was 1/13 345 in newborns and 1/9 099 in mothers, respectively. The positive predictive value of this program was 15.5%. Taking cutoff values of C0<8.5 μmol/L or C0 8.5~9.9 μmol/L with (C3+C16)<2 μmol/L, the number of screen-positive cases would be reduced from 810 to 224 without additional false negative case, when compared with cutoff value C0<10 μmol/L only. Both levels of C0 and (C3+C16) at first screening were not significant difference between newborns with PCD and newborns born to mothers with PCD ((6.2±2.4) vs. (5.0±1.8) μmol/L, (1.4±0.4) vs. (1.2±0.5) μmol/L, t=3.826, 0.326; P=0.058, 0.572). Seven PCD mothers experienced moderate fatigue and dizziness in the morning. One of them presented with cardiomyopathy in pregnancy. Genetic analysis of the SLC22A5 gene showed that p.S467C, p.F17L, p.R254X were the three most common variants in newborns with PCD. In PCD mothers and healthy children, the p.S467C, p.F17L and R399W were the three most common whereas the severe variant p.R254X was rare. The population carrier rate for pathogenic variants was 1 in 65 and the estimated incidence of PCD was about 1/16 500. Conclusions:Newborn screening can detect PCD both in newborns and mothers. Adding a quantitative biomarker (C3+C16) <2 μmol/L into the newborn screening program can improve the PCD screen performance. The severe variant p.R253X was common in PCD newborns but rare in PCD mothers and healthy children, indicating that the current screening program maybe failed to detect all PCD newborns and under-estimated the incidence rate of PCD in Guangzhou.

Objective:To reveal the relationship between G6PD genotypes and the G6PD enzyme activities in dried blood spots of newborn screening.Methods:Simple random sampling procedure was used in this study. The fluorescence PCR melting curve analysis was performed to classify G6PD gene variants in 635 neonates coming from Guangzhou Newborn Screening Center during October 1 to 20, 2016, including 15 reported variants. Those samples consisted of 377 cases with screening positive results (261 from males and 116 from females) and 258 cases with screening negative results (32 from males and 226 from females). The cut-off value of G6PD was less than 2.6 U/g Hb in dry blood spots. Sanger sequencing for G6PD gene was used in 7 cases with screening negative results under simple random sampling. One-way ANOVA and least significant difference method (LSD) test were performed to compare the difference of G6PD activity among genotypes.Results:The top 6 frequency of G6PD gene variants were c.1388G>A(35.07%), c.1376G>T(32.13%), c.95A>G(12.72%), c.871G>A(8.32%), c.1024C>T(4.08%) and c.392G>T(2.28%), accounting for 94.62% of all variant alleles (580/613). A total of 253 males positive for enzyme activity were detected to have gene mutations. The positive rate of G6PD enzyme activity was 98.06%(253/258). The mean values of G6PD activities for c.1376G>T,c.95A>G and c.1388G>A were 0.85, 1.10 and 1.28 U/g Hb, respectively. There were significant differences among the three groups ( F=28.7, P<0.01). A total of 105 females positive for enzyme activity were detected to have gene mutations. The positive rate of G6PD enzyme activity was 90.52%(105/116). The positive rate of G6PD enzyme activity was 26.95% among 256 females with one point mutation while it was 83.72% in females with multi-allele variants. The G6PD activity of heterozygous females was (2.9±0.8) U/g Hb, which was significant higher than that of females with multi-allele variants (1.5±1.0) U/g Hb ( t=8.6, P<0.01). Conclusions:G6PD activities in dried blood spots were related to G6PD genotypes in males. They were also associated with the numbers of allele variants in females. Newborn screening for G6PD deficiency can be used to detect most of G6PD-deficient hemizygotes and female patients with multi-allele variants, which is helpful for preventing neonatal jaundice and medicine application.

Objective:To reveal the relationship between G6PD genotypes and the G6PD enzyme activities in dried blood spots of newborn screening.Methods:Simple random sampling procedure was used in this study. The fluorescence PCR melting curve analysis was performed to classify G6PD gene variants in 635 neonates coming from Guangzhou Newborn Screening Center during October 1 to 20, 2016, including 15 reported variants. Those samples consisted of 377 cases with screening positive results (261 from males and 116 from females) and 258 cases with screening negative results (32 from males and 226 from females). The cut-off value of G6PD was less than 2.6 U/g Hb in dry blood spots. Sanger sequencing for G6PD gene was used in 7 cases with screening negative results under simple random sampling. One-way ANOVA and least significant difference method (LSD) test were performed to compare the difference of G6PD activity among genotypes.Results:The top 6 frequency of G6PD gene variants were c.1388G>A(35.07%), c.1376G>T(32.13%), c.95A>G(12.72%), c.871G>A(8.32%), c.1024C>T(4.08%) and c.392G>T(2.28%), accounting for 94.62% of all variant alleles (580/613). A total of 253 males positive for enzyme activity were detected to have gene mutations. The positive rate of G6PD enzyme activity was 98.06%(253/258). The mean values of G6PD activities for c.1376G>T,c.95A>G and c.1388G>A were 0.85, 1.10 and 1.28 U/g Hb, respectively. There were significant differences among the three groups ( F=28.7, P<0.01). A total of 105 females positive for enzyme activity were detected to have gene mutations. The positive rate of G6PD enzyme activity was 90.52%(105/116). The positive rate of G6PD enzyme activity was 26.95% among 256 females with one point mutation while it was 83.72% in females with multi-allele variants. The G6PD activity of heterozygous females was (2.9±0.8) U/g Hb, which was significant higher than that of females with multi-allele variants (1.5±1.0) U/g Hb ( t=8.6, P<0.01). Conclusions:G6PD activities in dried blood spots were related to G6PD genotypes in males. They were also associated with the numbers of allele variants in females. Newborn screening for G6PD deficiency can be used to detect most of G6PD-deficient hemizygotes and female patients with multi-allele variants, which is helpful for preventing neonatal jaundice and medicine application.

Objective To study the influence of postnatal age and season of sample collection on congenital hypothyroidism (CH) screening and to determine the appropriate cut-off value. Method From January 2015 to December 2017, neonatal thyroid stimulating hormone (TSH) screening data in Guangzhou were retrospectively analysed. The infants were assigned into four groups according to sampling postnatal age:24～＜48 h, 48～＜72 h, 3～＜7＜d and≥7 d, and assigned into another four groups according to their birth seasons. Based on the data of 2015 and 2016, the cut-off value of TSH for hypothyroidism were adjusted. The data of 2017 were used to verify the accuracy of the adjusted cut-off value. The cut-off value was determined based on the receiver operating characteristic (ROC) curve and percentile method. Specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) of the cut-off value were also calculated. Result A total of 459854 newborns were screened from 2015 to 2016. 7329 were positive in preliminary screening, 371 were still positive after recall for re-examination, and 318 were confirmed with CH eventually. The optimal TSH cut-off value calculated using ROC curve was 9 mIU/L, with a percentage of 98.7. The cut-off value with sampling time≥48 h was set to 9 mIU/L in spring, summer and autumn, and 10 mIU/L in winter. The cut-off of sampling time 24～＜48 h was set to 10 mIU/L in all seasons. The data of 264993 newborns screened in 2017 were verified using the adjusted cut-off value. The overall positive rate was reduced from 1.27％to 1.02％, and the PPV was increased from 6.07％to 7.58％without adding false negative cases. Conclusion Adjusting cut-off values of TSH for CH screening according to postnatal age and season can effectively reduce false positive rates.

Objective:To analyse the clinical features of encephalitis patients with antibodies against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR).Methods:Three anti-AMPAR encephalitis patients diagnosed in Tangdu Hospital, the Air Force Military Medical University between January 2020 and May 2021 were retrospectively reviewed. The clinical symptoms, supplementary examination, treatment options and outcomes with knowledge from literature were summarized in this study.Results:Three patients aging from 12 to 70 years presented with symptoms ranging from cognitive impairment, personality change to headache and paralysis. The lung occupying lesion was pathologically proved to be small cell lung cancer in case 1. Antibody to AMPAR (AMPAR-ab) was positive in both blood and cerebrospinal fluid of case 1, with coexisting antibodies against sex-determining region of Y chromosome-related high mobility group box 1 in blood, and the symptoms persisted but did not recur following therapy with corticosteroids. AMPAR-ab was detected only in serum in case 2, with the lesion located in both frontal and temporal lobes, centrum semiovale and lateral ventricle, combined with classic imaging features of intracranial hypotension, and the syndrome was partially improved following treatment with corticosteroids. The lesions were located in the pons and middle cerebellar peduncle, accompanied by cerebellar atrophy in case 3. Spinal cord magnetic resonance imaging showed long hyperintense lesions involving the cervical and thoracic cord, extending from C 2 to Th 10 level on T 2-weighted images. AMPAR-ab was positive in both serum and cerebrospinal fluid. And the symptoms improved significantly following treatment with corticosteroids and intravenous immunoglobulin. Conclusions:The clinical manifestations of anti-AMPAR encephalitis are highly heterogeneous, and brainstem and spinal cord can also be involved in addition to the limbic system, accompanied by brain atrophy. Combining with concurrent antibodies, especially the intracellular antibodies, malignancy needs to be closely monitored; the immunotherapy is effective and the presence of tumor superimposed with multiple antibodies may be associated with poor prognosis.

Objective: To explore the TPO, DUOX2 and DUOXA2 genotypes and phenotypes of children with permanent congenital hypothyroidism(PCH) suspected dyshormonogenesis in Guangzhou, identified and treated at Guangzhou Newborn Screening Center. Six of them were born between 2011 and 2012. Method: Retrospectively analyzed the clinical data of 9 children with PCH suspected dyshormonogenesis. Genetic analysis of TPO, DUOX2 and DUOXA2 genes were performed with Sanger sequencing. Result: Of the 9 patients, four were identified variants in TPO gene including three cases with biallelic variants and one case with monoallelic variant. Novel c. 1784G>C( p. R595T) variant in TPO was predicted to be damaging by SIFT and PolyPhen-2. Four patients harbored monoallelic known variants in DUOX2 gene and the other one harbored heterozygous known mutation c. 738C>G(p.Y246X) in DUOXA2 gene.Two adolescent patients with biallelic variants in TPO gene showed classical PCH phenotypes with thyroid goiter or nodules. The six patients with monoallelic variant in TPO, DUOX2 or DUOXA2 presented variable phenotypes. Among the 433 578 newborns in the 2011-2012 cohort, there were 156 cases of CH. Six of these cases were PCH suspected dyshormonogenesis, among which 1 case was confirmed TPO biallelic variants and 5 cases were monoallelic variants of TPO, DUOX2, or DUOXA2 genes. Conclusion TPO and DUOX2 variants are the common molecular pathogenesis in children with PCH suspected dyshormonogenesis. Monoallelic variants in TPO, DUOX2 or DUOXA2 are associated with PCH and showed wide variability in their phenotypes. The novel variant p. R595T in TPO is probably a pathologic variant. The prevalence of PCH caused by TPO gene defects is rare in Guangzhou.