ABSTRACT
A new COVID-19 epidemic model with media coverage and quarantine is constructed. The model allows for the susceptibles to the unconscious and conscious susceptible compartment. First, mathematical analyses establish that the global dynamics of the spread of the COVID-19 infectious disease are completely determined by the basic reproduction number R0. If R0 ≤ 1, then the disease free equilibrium is globally asymptotically stable. If R0 > 1, the endemic equilibrium is globally asymptotically stable. Second, the unknown parameters of model are estimated by the MCMC algorithm on the basis of the total confirmed new cases from February 1, 2020 to March 23, 2020 in the UK. We also estimate that the basic reproduction number is R0 = 4.2816(95%CI: (3.8882, 4.6750)). Without the most restrictive measures, we forecast that the COVID-19 epidemic will peak on June 2 (95%CI: (May 23, June 13)) (Figure 3a) and the number of infected individuals is more than 70% of UK population. In order to determine the key parameters of the model, sensitivity analysis are also explored. Finally, our results show reducing contact is effective against the spread of the disease. We suggest that the stringent containment strategies should be adopted in the UK.
Subject(s)
Betacoronavirus , Communications Media , Coronavirus Infections/epidemiology , Pandemics , Pneumonia, Viral/epidemiology , Quarantine , Algorithms , Basic Reproduction Number/statistics & numerical data , COVID-19 , Coronavirus Infections/prevention & control , Coronavirus Infections/transmission , Humans , Markov Chains , Mathematical Concepts , Models, Biological , Monte Carlo Method , Pandemics/prevention & control , Pandemics/statistics & numerical data , Pneumonia, Viral/prevention & control , Pneumonia, Viral/transmission , SARS-CoV-2 , Time Factors , United Kingdom/epidemiologyABSTRACT
Subclinical hypothyroidism is common in pregnant women and often related to adverse pregnancy outcomes, but its relationship with gestational diabetes remains controversial. In particular, the impact of thyroperoxidase antibodies status on the relationship between subclinical hypothyroidism and gestational diabetes is not clear. We investigated the association between combined thyroid stimulating hormone (TSH) level and thyroperoxidase antibodies status in early pregnancy (<20 weeks of gestation) and gestational diabetes mellitus. A total of 7084 pregnant women met the inclusion criteria, which included thyroperoxidase antibodies-positive subclinical hypothyroidism [TSH(H)TPOAb(+)] (n = 78), thyroperoxidase antibodies-negative subclinical hypothyroidism [TSH(H)TPOAb(-)] (n = 281), thyroperoxidase antibodies-positive euthyroidism [TSH(N)TPOAb(+)] (n = 648), and thyroperoxidase antibodies-negative euthyroidism [TSH(N)TPOAb(-)] (n = 6077). Of the 7084 cases included in our study, 1141 cases were diagnosed with gestational diabetes mellitus at 24-28 weeks of pregnancy. The prevalence of gestational diabetes mellitus in TSH(N)TPOAb(-), TSH(H)TPOAb(-), TSH(N)TPOAb(+), and TSH(H)TPOAb(+) was 14.65, 19.57, 24.85, and 46.15 %, respectively. Compared with TSH(N)TPOAb(-) women, the risk of gestational diabetes mellitus was increased in all other groups of women in early pregnancy. After dividing early pregnancy into first and second trimesters, we found that TSH(H)TPOAb(-) women in the first trimester do not show this increase. Our study suggests that subclinical hypothyroidism and thyroperoxidase antibodies-positive euthyroidism in early pregnancy are associated with an increased risk of gestational diabetes mellitus.
Subject(s)
Diabetes, Gestational/blood , Iodide Peroxidase/immunology , Thyrotropin/blood , Adult , Female , Humans , Pregnancy , Pregnancy Trimesters , Prospective Studies , Risk AssessmentABSTRACT
BACKGROUND: The correlation between gestational hypertension-preeclampsia (GH-PE) and placenta previa (PP) is controversial. Specifically, it is unknown whether placenta previa has any effect on the various types of preeclampsia (PE), and the role PP with concurrent placenta accreta (PA) play in the occurrence of GH-PE are not well understood. OBJECTIVE: The aim of this study was to identify the effects of PP on GH, mild and severe preeclampsia (MPE and SPE), and early- and late-onset preeclampsia (EPE and LPE). Another aim of the study was to determine if concurrent PA impacts the relationship between PP and GH-PE. METHODS: A retrospective single-center study of 1,058 patients having singleton pregnancies with PP was performed, and 2,116 pregnant women were randomly included as controls. These cases were collected from a tertiary hospital and met the inclusion criteria for the study. Clinical information, including PP and the gestational age at the onset of GH-PE were collected. Binary and multiple logistic regression analyses were conducted after the confounding variables were controlled to assess the effects of PP on different types of GH-PE. RESULTS: There were 155 patients with GH-PE in the two groups. The incidences of GH-PE in the PP group and the control group were 2.5% (26/1058) and 6.1% (129/2116), respectively (P = 0.000). Binary and multiple regression analyses were conducted after controlling for confounding variables. Compared to the control group, in the PP group, the risk of GH-PE was reduced significantly by 78% (AOR: 0.216; 95% CI: 0.135-0.345); the risks of GH and PE were reduced by 55% (AOR: 0.451; 95% CI: 0.233-0.873) and 86% (AOR: 0.141; 95% CI: 0.073-0.271), respectively; the risks of MPE and SPE were reduced by 73% (AOR: 0.269; 95% CI: 0.087-0828) and 88% (AOR: 0.123; 95% CI: 0.055-0.279), respectively; and the risks of EPE and LPE were reduced by 95% (AOR: 0.047; 95% CI: 0.012-0.190) and 67% (AOR: 0.330; 95% CI: 0.153-0.715), respectively. The incidence of concurrent PA in women with PP was 5.86%; PP with PA did not significantly further reduce the incidence of GH-PE compared with PP without PA (1.64% vs. 2.51%, P>0.05). Binary logistic regression analyses were conducted after controlling for confounding variables, compared with the non-PP + GH-PE group, and the AOR of FGR in the non-PP + non-GH-PE group was 0.206 (0.124-0.342). Compared with the PP + GH-PE group, the AOR of FGR in the PP + non-GH-PE group was 0.430 (0.123-1.500). CONCLUSION: PP is not only associated with a significant reduction in the incidence of GH-PE, but also is associated with a reduction in incidence of various types of PE. Concurrent PA and PP do not show association with a reduction in incidence of GH-PE.
Subject(s)
Hypertension, Pregnancy-Induced/epidemiology , Placenta Previa/epidemiology , Pre-Eclampsia/epidemiology , Adult , Female , Humans , Incidence , Placenta Accreta/epidemiology , Pregnancy , Retrospective Studies , Risk Factors , Young AdultABSTRACT
OBJECTIVE: Idiopathic short stature (ISS) refers to extreme short stature without any diagnostic explanation. Recently, three genome-wide association studies discovered associations between the ZBTB38 and adult height in different populations. Therefore, variations in the ZBTB38 might contribute to ISS. Furthermore, one study in Korean population showed that ZBTB38 gene was significantly associated with adult height, but not with ISS. We want to examine whether the variants in ZBTB38 are associated with ISS in Chinese Han. METHODS: A case-control association study was performed in 268 ISS patients and 513 healthy controls from Chinese Han population. Fourteen tag SNPs were selected and genotyped using SNaPshot method. Furthermore, expression of mRNA was quantified by RT-qPCR, and assessment of allelic expression imbalance was conducted with SNaPshot method. RESULTS: Seven ZBTB38 SNPs were significantly associated with ISS by allele tests (rs724016, rs1582874, rs11919556, rs6440006, rs7612543, rs62282002, rs18651435). And five loci were associated with ISS according to genotype (rs11919556, rs16851419, rs6440006, rs62282002, rs18651435). Notably, after applying the stringent Bonferroni correction for multiple testing, one SNP, rs16851435, remained significantly associated by allele and genotype (P = 5·30 × 10â»4 for allele and P = 0·002 for genotype). Furthermore, the rs16851435 alleles were investigated association with ZTBT38 mRNA expression levels. The G allele showed a higher transcriptional activity than the T allele (P = 0·002). CONCLUSIONS: Our study indicated that the nonsynonymous SNP (rs16851435:T > G,p.Ser319Ala) of ZBTB38 was contributed to susceptibility of ISS in the Chinese Han population.
Subject(s)
Body Height , Polymorphism, Single Nucleotide , Repressor Proteins/genetics , Alleles , Asian People/genetics , Case-Control Studies , Child , China , Female , Gene Expression Profiling , Genome-Wide Association Study , Genotype , Humans , Male , Reverse Transcriptase Polymerase Chain Reaction , Transcription, GeneticABSTRACT
OBJECTIVE: To compare the difference in maternal outcomes between early and late use of transverse annular compression sutures (TACS) during cesarean delivery among women with complete placenta previa (CPP). METHODS: A retrospective study of 36 women with CPP was conducted. Percentiles of blood loss before TACS were calculated. The transfusion rate, sensitivity, specificity, Youden index, positive predictive value, and negative predictive value were also estimated. Patients were assigned to either the early TACS group or the late TACS group based on the highest Youden index. Maternal outcomes of the 2 groups were compared. RESULTS: The Youden index for transfusion rate was highest when blood loss before TACS reached 500 mL. Blood loss before intervention in the late TACS group was significantly higher than in the early TACS group (735.0 ± 123.7 mL versus 396.9 ± 76.3 mL; P<0.001). More women in the late TACS group than in the early TACS group required blood transfusion (60.0% versus 12.5%; P=0.004) and the volume of blood transfused was significantly lower in the early TACS group than in the late TACS group (137.5 ± 377.5 mL versus 806.7 ± 619.3 mL; P=0.001). CONCLUSION: Early implementation of TACS could lead to improved maternal outcomes.
Subject(s)
Cesarean Section/methods , Placenta Previa/surgery , Postpartum Hemorrhage/prevention & control , Suture Techniques , Adult , Blood Loss, Surgical/prevention & control , Blood Transfusion/methods , Female , Humans , Predictive Value of Tests , Pregnancy , Pregnancy Outcome , Retrospective Studies , Sensitivity and Specificity , Time Factors , Treatment Outcome , Young AdultABSTRACT
OBJECTIVE: To analyze clinical characteristics of children with 45, X/46, XY mosaicism and explore effective managements for them. METHOD: Five children with 45, X/46, XY mosaicism were all in puberty period, of whom, three were female and two male. The standing height, weight and sexual development were measured. The levels of sex hormones, other endocrine parameters were also determined, and imaging examinations were performed. RESULT: All the patients had disorders of sex development, of whom, 4 had short stature, and the HtSDs was -2.8 ± 1.1. The results of laboratory indexes suggested that 4 had hypergonadotropic hypogonadism, with the average level of LH (13.5 ± 5.8) IU/L and FSH (56.8 ± 37.4) IU/L. Imaging examinations revealed that 2 cases had cryptorchidism, 1 had immature uterus, 1 had testicular dysgenesis and 1 had normal testis. Three patients received rhGH treatment and 1 took gender assignment into account. CONCLUSION: Patients with mosaic 45, X/46, XY karyotypes had a wide range of phenotypic manifestations, and disorders of sex development and short stature were the main clinical features. However, the disorders of sex development varied among these patients. And the management for them depends upon many factors and needs to be individualized based on the cooperation with different clinical departments.
Subject(s)
Developmental Disabilities/complications , Sex Chromosome Aberrations , Adolescent , Child , Chimerism , Female , Gonadal Dysgenesis, 46,XY/complications , Humans , Male , Sexual Development , Turner Syndrome/complicationsABSTRACT
OBJECTIVE: To assess the influence of growth hormone receptor (GHR) Ex3 genotype on the short-term response to recombinant human growth hormone (rhGH) therapy in children with idiopathic short stature (ISS). METHODS: Thirty prepubertal children with ISS receiving rhGH treatment [0.116±0.02 IU/(kg/d)] were randomly recruited. The GHR Ex3 locus was genotyped using a PCR multiplex assay. The growth data including growth velocity, height SDS for chronological age (HtSDSCA), height SDS for bone age (HtSDSBA) and predict final height were compared in children with different GHR genotypes 6 months after rhGH treatment. RESULTS: After 6 months of rhGH treatment, the children with ISS carrying d3/d3 alleles showed a significantly higher increment in growth velocity than those carrying fl/fl alleles (6.3±1.6 cm/year vs 3.4±0.5 cm/year; P<0.05). CONCLUSIONS: The polymorphism in GHR Ex3 is associated with the responsiveness to rhGH treatment, showing that the growth velocity in ISS children with d3/d3 genotype is significantly higher than those with fl/fl genotype.
Subject(s)
Exons , Growth Disorders/drug therapy , Growth Disorders/genetics , Human Growth Hormone/therapeutic use , Polymorphism, Genetic , Receptors, Somatotropin/genetics , Child , Female , Genotype , Humans , MaleABSTRACT
OBJECTIVE: To elucidate the curative and adverse effect of recombinant human growth hormone (rhGH) in 2 patients with isolated-growth hormone deficiency type IA (IGHDIA), to track sexual development and pregnancy, and reassess the quality of life in the adulthood. METHOD: The authors summarized the data of 2-sister cases with IGHDIA; followed up for assessment of height, weight, blood pressure and sexual development; detected fasting blood lipids, glucose, insulin, insulin growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3); made an investigation of education and occupation, and so on. RESULT: After 6.2 and 7.3 years treatment with rhGH, the two sisters had considerably improved height from -7.8 SDS, -8.8 SDS to -2.6 SDS and -1.3 SDS respectively. No evident side effect was observed. They had normal sexual development and pregnancy. The levels of IGF-1 and IGFBP-3 were still low, in the elder sister they were 46.6 µg/L, 2460 µg/L, and in the younger 52.4 µg/L, 2430 µg/L. No hyperlipidemia, diabetes or obesity occurred. CONCLUSION: Long term therapy with rhGH may improve final adult height of individuals with IGHDIA. They can have normal sexual development and pregnancy. Metabolic syndrome did not occur during the follow-up period.
Subject(s)
Dwarfism, Pituitary/classification , Child , Dwarfism, Pituitary/therapy , Female , Follow-Up Studies , Human Growth Hormone/therapeutic use , Humans , SiblingsABSTRACT
OBJECTIVE: To detect CYP17A1 gene mutation in a patient with 17 alpha-hydroxylase/17, 20-lyase deficiency and her family members. METHOD: Genomic DNA was extracted from the blood of the patient, her parents and twin sister. The 8 exons of CYP17A1 gene were amplified with polymerase chain reaction (PCR) and screened for mutations by sequencing. RESULT: The analysis revealed that the patient was a compound heterozygote carrying two different inherited point mutations on CYP17A1 gene. They were nt186delC on exon 1 and nt1085G > A on exon 6. This type of mutation could induce 17OHD because of complete loss of 17 alpha-hydroxylase activities. And her parents and the twin sister were carriers on CYP17A1 gene. In addition, the mutation nt186delC was a novel point mutation and it was not discovered in normal children. CONCLUSION: A new compound heterozygote carrying two different inherited point mutations on CYP17A1 gene was found, and her parents and twin sister were carriers. This is probably the first report in the world of a twin sisters of whom one is a patient with 17OHD and the other is a carrier of CYP17A1 gene mutation.
Subject(s)
Adrenal Hyperplasia, Congenital/genetics , Steroid 17-alpha-Hydroxylase/genetics , Child , DNA Mutational Analysis , Exons , Female , Heterozygote , Humans , Male , Pedigree , Point MutationABSTRACT
OBJECTIVE: Inactivating mutations of DAX-1 give rise to the X-linked form of adrenal hypoplasia congenita (AHC). Affected individuals are at risk of early postnatal Addisonian crisis, but the variable phenotypic expression of DAX-1 insufficiency renders this diagnosis challenging. This study aimed to understand the clinical features and identify DAX-1 gene mutation of the affected individuals and their relatives in a Chinese adrenal hypoplasia congenita kindred. METHODS: The proband was diagnosed as adrenal insufficiency shortly after birth and his elder cousin was also diagnosed as having this disease at the age of about 8 years. Clinical data were obtained from 2 affected individuals when they were hospitalized into the department of pediatrics, Ruijin Hospital in 2006; 20 peripheral blood samples were obtained from the affected individuals and their relatives; exons in DAX-1 gene were amplified, and PCR product was purified and sequenced directly for analyzing mutation. RESULTS: A novel hemizygous mutation (T785C) was found in DAX-1 gene in both patients. Some clinical features such as the age of onset were different although these 2 patients carried the same mutation. There were 5 carriers of this mutation in the patients' maternal pedigree. CONCLUSION: The results suggested that adrenal hypoplasia congenita in this kindred was caused by a novel mutation (T785C) in DAX-1 gene, and the same mutation can give rise to the variable phenotype.
Subject(s)
Adrenal Hyperplasia, Congenital/genetics , DAX-1 Orphan Nuclear Receptor/genetics , Genetic Diseases, X-Linked/genetics , Mutation , Asian People/genetics , Child , Humans , Male , Pedigree , Receptors, Retinoic Acid/genetics , Repressor Proteins/geneticsABSTRACT
OBJECTIVE: To explore the effects of dietary fat on gestational diabetes mellitus (GDM). METHODS: Nulliparous pregnant women with GDM (GDM group, n = 85) were compared with normal pregnant women (normal pregnant group, NP group, n = 159). A 24 hours recall dietary assessment was obtained before dietary intervention. From the dietary record a list of the amount of foods consumed, were entered into a software program. The analysis was focused on three nutrients (carbohydrate, protein and fat), especially on dietary fat and fat subtypes. RESULTS: (1) Total calorie per day in GDM group (8970 +/- 2115) kJ was higher than that in NP group (8799 +/- 1785) kJ, but there was no significant difference between two groups (P > 0.05). (2) Carbohydrate, protein and fat intake in GDM group (as % kJ) was 51.9 +/- 7.2, 17.5 +/- 0.9 and 30.6 +/- 1.3, respectively. Carbohydrate, protein and fat intake in NP group (as % kJ) was 53.6 +/- 8.1, 18.3 +/- 1.1 and 28.1 +/- 2.3 respectively. Fat intake (as % kJ) in GDM group was significantly higher than that in NP group (P < 0.05), while carbohydrate and protein intake (as % kJ) in GDM group was not significantly different compared with NP group (P > 0.05). (3) Polyunsaturated fatty acids (PUFA) in GDM group (as % kJ) (8.3 +/- 0.5) was lower than that in NP group (10.1 +/- 0.4) (P < 0.05), but saturated fatty acids (SFA) in GDM group (as % kJ) (15.2 +/- 0.4) was higher than that in NP group (11.7 +/- 0.6) (P < 0.05). Although monounsaturated fatty acids (MUFA) in GDM group (as % kJ) (7.1 +/- 0.5) was higher than that in NP group (6.3 +/- 0.3), there was no significant difference between two groups. CONCLUSION: High dietary fat, high SFA and low PUFA may be one of the high-risk factors triggering GDM.
Subject(s)
Diabetes, Gestational/etiology , Dietary Fats/administration & dosage , Adult , Blood Glucose/analysis , Diabetes, Gestational/prevention & control , Diet Records , Dietary Carbohydrates/administration & dosage , Dietary Fats/adverse effects , Dietary Proteins/administration & dosage , Energy Intake , Fatty Acids/administration & dosage , Fatty Acids, Unsaturated/administration & dosage , Female , Gestational Age , Glucose Tolerance Test , Humans , Insulin/blood , Pregnancy , Risk FactorsABSTRACT
OBJECTIVE: To assess the state of glucose metabolism and beta-cell function in obese and overweight children. METHODS: Levels of glucose and insulin were detected during oral glucose tolerance test in 52 obese and overweight children aged 11.3 +/- 1.8 years with body mass index (BMI) 30.2 +/- 19.2 kg/m(2). Insulin resistance index (IR = FIN x FPG/22.5), insulin sensitivity index (IS = 1/FIN x FPG) and ratio of insulin increment to glucose increment at 30' (I(30)-I(0)/G(30)-G(0)) post oral glucose were measured. (FIN = fasting insulin. FPG = fasting plasma glucose). The IR, IS and the ratio post oral glucose were compared among groups with varying BMI and between groups of impaired glucose tolerance (IGT) and control. Serum triglyceride determination and B ultrasonography of liver were performed. RESULTS: (1) one patient with type 2 diabetes (1.9%) and 5 patients with IGT (9.6%) were found. (2) IR (> or = 2.8) was observed in 76.9% of the cases. (3) The IR, IS and their ratio showed no difference between the compared groups. (4) IR and IS did not show significant difference but there was significant difference in ratio between the IGT and control group. (5) Increased serum triglyceride and fatty liver were noted in 36.5% and 53.3% of the cases, respectively. CONCLUSION: The results indicated that insulin resistance and reduced insulin sensitivity in obese and overweight children are common, and these changes seemed not to correlated with the varying degree of BMI. Beta-cells function was obviously impaired in obese children with IGT and disorder of lipid metabolism exists in many obese and overweight children revealed.
Subject(s)
Insulin/metabolism , Obesity/metabolism , Overweight/metabolism , Adolescent , Body Mass Index , Child , Female , Glucose Tolerance Test , Humans , Insulin Resistance , Insulin Secretion , MaleABSTRACT
OBJECTIVE: To evaluate the number of cells in coelomic fluid by DNA quantitation with picogreen and to establish a new method of prenatal diagnosis for sex-linked disorders in early pregnancy. METHODS: Coelomic fluid and chorionic villi were obtained from 25 women undergoing planned termination of pregnancy. DNA of coelomic fluid was extracted by boiling method and DNA concentration was measured with picogreen, and fetal gender was determined by X and Y-sequence-specific PCR. The results of PCR were compared with traditional cytogenetic analysis of chorionic villi. RESULTS: There were 750-6270 cells in 0.5-3 ml coelomic fluid. Two amplified bands of X and Y were identified simultaneously in the coelomic fluid of male-fetus. Only one band was detected in that of female-fetus. Eleven out of 25 coelomic fluids showed X and Y bands, and the others were one band (X). The overall concordance rate of gender determination between coelomic fluid and chorionic villi was 100%. CONCLUSION: The number of cells in 0.5-3 ml coelomic fluid can completely meet the needs of PCR reactions. Sex determination using cells in coelomic fluid and PCR is reliable, which can be used as a prenatal diagnostic test for sex-linked disorders and has the advantages of high sensitivity and rapidity.
Subject(s)
DNA/analysis , Genetic Diseases, Inborn/diagnosis , Prenatal Diagnosis/methods , Body Fluids/chemistry , DNA Primers , Female , Fetus/cytology , Genetic Linkage , Humans , Male , Polymerase Chain Reaction , Pregnancy , Pregnancy Trimester, First , Sex PreselectionABSTRACT
OBJECTIVE: To evaluate the therapeutic effect of China-made recombinant human growth hormone (r-hGH) in children with growth hormone deficiency (GHD) and to investigate the utilities of various biochemical parameters in GHD diagnosis and treatment. METHODS: Our study comprises of 30 normal children and 71 GHD children treated with China-made r-hGH substitution therapy 0.1 IU x kg(-1) x d(-1) for 6 months. Serum insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), bone turnover markers (Ost, ICTP), and anti-growth hormone antibody (GHAb) were detected before and after r-hGH treatment. RESULTS: After the first 3 and 6 months of treatment, growth velocities of GHD children were significantly increased (13.1 +/- 3.7 and 12.6 +/- 3.6 cm/year) compared with pretreatment values (2.9 +/- 0.8 cm/year, P < 0.01). GHD Children had obviously reduced serum levels of IGF-1, IGFBP-3, and bone turnover markers (Ost, ICTP) compared with normal controls (P < 0.01), and these biochemical parameters improved significantly after treatment (P < 0.01). Growth hormone antibodies were positive in 17 of 45 cases after treatment by binding capacity detection. The binding percentage of growth hormone antibody which was increased more than 30% after the treatment showed a negative correlation with growth velocity (P < 0.01). CONCLUSIONS: (1) The growth stimulating effect and safety were confirmed in using China-made r-hGH in the treatment of GHD children for 6 months. (2) The measurements of serum IGF-1 and IGFBP-3 may serve as useful parameters in the diagnosis of GHD. (3) Serum Ost and ICTP are useful laboratory criteria for evaluating the effect of r-hGH therapy in the early stage. (4) It is necessary to monitor serum levels of GHAb during r-hGH therapy.
Subject(s)
Growth Hormone/deficiency , Human Growth Hormone/therapeutic use , Adolescent , Body Height/drug effects , Body Mass Index , Body Weight/drug effects , Child , Collagen/blood , Collagen Type I , Female , Follow-Up Studies , Humans , Insulin-Like Growth Factor Binding Protein 3/blood , Insulin-Like Growth Factor I/metabolism , Male , Osteocalcin/blood , Peptides/blood , Recombinant Proteins/therapeutic useABSTRACT
OBJECTIVE: Prader-Willi syndrome (PWS) is an example of a human genetic disorder that involves imprinting genes on the proximal long arm of chromosome 15 and SNRPN gene as a candidate gene for this syndrome. The purpose of this study was to show the molecular genetic defects and genomic imprinting basis in Chinese PWS patients and to evaluate the clinical applications of a differential diagnostic test for PWS. METHODS: Fluorescence in situ hybridization (FISH) and methylation-specific PCR (MSPCR) techniques were applied for 4 clinically suspected PWS patients. Using three probes, including SNRPN probe for identification of the critical locus in PWS region, D15Z1 and PML control probes for identification of the 15p arm and 15q arm, the authors detected the deletions 15q in PWS. MSPCR was based on sodium bisulfite treatment of DNA and PCR primers specific for the maternal and paternal allele. RESULTS: When hybridized with mixed probes, it was found in 2 patients that the central specific signal was absent, but both the flanking control signals were retained, indicating SNRPN gene deletion of chromosome 15q11-13. Bisulfite-modified DNA from all PWS children amplified with methylated allele-specific primer pair showed only maternal 131bp PCR product, indicating the maternal uniparental disomy (UPD15). CONCLUSION: Genomic imprinting plays an important role in the molecular pathogenesis of PWS that caused by paternal microdeletions of 15q11-q13 or maternal UPD of chromosome 15. The basic defect seemed to be an absence of function of PWS genes that are normally expressed only from the paternal chromosome 15. MSPCR is a rapid and simple PCR-based assay compared with other cyto-molecular tests and its results were consistent with the clinical diagnosis of PWS, so it seems to be a reliable diagnostic method for PWS patients who show abnormal methylation at SNRPN. The genetic differential tests for PWS are important in determining familial recurrence risk.