Relationship Between Gene-Phenotype and Clinical Manifestations of Chromosomal Copy Number Variations Indicated by Non-Invasive Prenatal Testing

Objective:To analyze the clinical value of non-invasive prenatal testing(NIPT)in detecting chromosomal copy number variations(CNVs)and to explore the relationship between gene expression and clinical manifestations of chromosomal copy number variations.Methods:3551 naturally conceived singleton pregnant women who underwent NIPT were included in this study.The NIPT revealed abnormalities other than sex chromosome abnormalities and trisomy 13,18,and 21.Pregnant women with chromosome copy number variations underwent genetic counseling and prenatal ultrasound examination.Interventional prenatal diagnosis and chromosome microarray analysis(CMA)were performed.The clinical phenotypes and pregnancy outcomes of different prenatal diagnoses were analyzed.Additionally,a follow-up was conducted by telephone to track fetal development after birth,at six months,and one year post-birth.Results:A total of 53 cases among 3551 cases showed chromosomal copy number variation.Interventional prenatal diagnosis was performed in 36 cases:27 cases were negative and 8 were consistent with the NIPT test results.This indicates that NIPT’s positive predictive value(PPV)in CNVs is 22.22%.Conclusion:NIPT has certain clinical significance in screening chromosome copy number variations and is expected to become a routine screening for chromosomal microdeletions and microduplications.However,further interventional prenatal diagnosis is still needed to identify fetal CNVs.

Prenatal ultrasonic characteristics and diagnosis of fetal Currarino syndrome:Report of 2 cases and review of literature

Objective To explore prenatal ultrasonic characteristics of fetal Currarino syndrome(CS)and methods for prenatal diagnosis of CS.Methods Two fetuses with CS confirmed by genetic examination were retrospectively analyzed,while 6 CS fetuses with complete prenatal ultrasonic data in literature were reviewed.Prenatal ultrasonic characteristics of CS fetuses and the method for prenatal diagnosis of CS were discussed.Results Among 8 CS fetuses diagnosed with prenatal ultrasound,4 were female singletons with a clear family history of CS,and MNX 1 gene mutation was found in 1 fetus.The other 4 fetuses were 2 pairs of male monochorionic twins,all with MNX 1 gene mutation.Among 8 CS fetuses,complete triad(sacral agenesis abnormalities,anorectal malformation and presacral mass)were displayed only in 2 fetuses,while all 8 had sacral agenesis abnormalities and 6(6/8,75.00%)were detected with prenatal ultrasound,6 had low location of conus medullaris and 2(2/6,33.33%)detected with prenatal ultrasound.Conclusion Prenatal ultrasound was the first choice for non-invasive diagnosis of fetal CS.When one of sacral agenesis abnormalities,anorectal malformation and presacral mass was found with prenatal ultrasound,the possibility of CS should be considered,and fetal MRI,genetic examination and prenatal genetic counselling should be recommended if necessary.

Prenatal Diagnosis of an Apically Located Congenital Left Ventricular Aneurysm: A Rare Case

Congenital ventricular aneurysm is a very rare cardiac anomaly.A diagnosis can be made during the prenatal period using fetal echocardiography.This study presents a very rare apically located left ventricular aneurysm case,and the relevant literature was reviewed and discussed.In this case,a 35-year-old,gravida 2,parity 1 preg-nant woman at 24 weeks of gestation,displayed a wide aneurysmal image in the left ventricular apical wall on fetal echocardiography.There was a 1.79 mm muscular ventricular septal defect at the apical region of the interven-tricular septum.In the course of the color Doppler ultrasonography examination,an aberrantfibrous band within the left ventricle and consequent turbulentflow during systole were observed.The baby,born via cesarean section at 37 weeks of gestation,is now in its postnatal seventh month.However,during echocardiographic follow-ups,changes have been observed,including mild to moderate mitral insufficiency and a decrease in systolic function.Despite thesefindings,the clinical condition remains asymptomatic.It is of great importance to use a multidis-ciplinary approach in managing these rare cases that could lead to potential adverse outcomes during the antena-tal or postnatal periods.

Invasive Procedures for Prenatal Diagnosis in Salmaniya Medical Complex in Bahrain: A Retrospective Cross-Sectional Descriptive Study

Background: Prenatal diagnosis is the process of evaluating the presence of disease or potential disease in the fetus, this enables families to be better prepared before the birth of the baby. There are non-invasive prenatal diagnosis procedures and invasive prenatal diagnosis procedures. The invasive prenatal diagnosis procedures are CVS (chorionic villus sampling) and amniocentesis. The American College of Obstetricians and Gynecologists states that invasive diagnostic testing should be available to all women, regardless of age or risk. Objective: To determine the indications, outcome and results of diagnostic invasive prenatal procedures. Study setting: The obstetrics and Gynecology Department in Salmaniya Medical Complex in Kingdom of Bahrain. Study design: Retrospective descriptive study. Study subjects and Methods: This retrospective descriptive study was conducted on 175 pregnant women who underwent invasive prenatal procedures (CVS and amniocentesis) between January 2013 and December 2018 at SMC in Kingdom of Bahrain. All medical records of the participants were reviewed and entered the study. According to the implemented procedures, medical records were categorized into two chorionic villus sampling (CVS) and amniocentesis groups. The study subject will include indications of the procedures which are advanced maternal age, hematological disorders, genetic disorders, metabolic disorders, abnormal structural findings in fetal ultrasound and previous child with aneuploidy. In addition, the study will address the complications, outcome and results of procedures. Results: About half of our indications of the procedures were due to hematological disorders (47.6%) followed by abnormal structural findings in fetal ultrasound (30.1%) then genetic disorders (15.7%), metabolic disorders (4.8%) and advanced maternal age (1.8%). Regarding complications of the procedure;threatened miscarriage or loss of pregnancy within 3 weeks was (2.3%), amniotic fluid leakage (0.7%), abdominal cramps (0.7%) and Insufficient or contaminated sample (6.2%). Regarding outcome of the pregnancy, our results showed that the loss of pregnancy was (4.8%), intrauterine fetal death or still birth was (13.9%), live birth was (63.9%), preterm delivery was (7.8%), preterm premature rupture of membrane (PPROM) was (1.8%), limbs reduction was (0.0%). Termination of pregnancy outside the country was (7.8%) of chorionic villus sampling and amniocentesis. Conclusion: CVS and amniocentesis are useful outpatient procedures to detect diagnosis or to assess whether a patient is at increased risk of having an affected fetus and that will minimize the psychological impact on the patient and to provide a proper antenatal care to the pregnant women by her obstetrician and follow up to the baby by pediatrician. In this study it was observed that most of the patients who underwent the procedure were couples either carrier or affected to sickle cell disease or Beta thalassemia.

“Keyboard sign”and“coffee bean sign”in the prenatal diagnosis of ileal atresia:A case report

BACKGROUND Ileal atresia is a congenital abnormality where there is significant stenosis or complete absence of a portion of the ileum.The overall diagnostic accuracy of prenatal ultrasound in detecting jejunal and ileal atresia is low.We report a case of ileal atresia diagnosed prenatally by ultrasound examination with the“keyboard sign”and“coffee bean sign”.CASE SUMMARY We report a case of ileal atresia diagnosed in utero at 31 weeks'of gestation.Prenatal ultrasound examination revealed two rows of intestines arranged in an‘S’shape in the middle abdomen.The inner diameters were 1.7 cm and 1.6 cm,respectively.A typical“keyboard sign”was observed.The intestine canal behind the“keyboard sign”showed an irregular strong echo.There was no normal intestinal wall structure,showing a typical“coffee bean sign”.Termination of the pregnancy and autopsy findings confirmed the diagnosis.CONCLUSION The prenatal diagnosis of ileal atresia is difficult.The sonographic features of the“keyboard sign”and“coffee bean sign”are helpful in diagnosing the location of congenital jejunal and ileal atresia.

Prenatal ultrasound diagnosis of fetal maxillofacial teratoma:Two case reports

BACKGROUND Facial teratoma is a rare benign tumor that accounts for about 1.6%of all teratomas and can be diagnosed by prenatal ultrasound(US).The purpose of this report was to describe our experience with the diagnosis of fetal facial teratoma by prenatal US at second trimester to provide a reference for clinical diagnosis of fetal maxillofacial teratoma.CASE SUMMARY We present two cases of patients with abnormal fetal facial findings on US at second trimester of pregnancy in our department.Case 1 was a 31-year-old G3 P1+1 female,with US revealing a heterogeneous echogenicity of 32 mm×20 mm×31 mm on the fetal face,most of it located outside the oral cavity and filling the root of the oral cavity.Case 2 was a 29-year-old G1P0 female,with fetal head and neck US revealing a cystic-solid echo mass measuring 42 mm×33 mm×44 mm,the upper edge of the lesion reaching the palate and filling the oral cavity.The contours of the lesions were visualized using three-dimensional(3D)US imaging.Both patients decided to give up treatment.Biopsies of the lesions were performed after induction of labor,and diagnosed as maxillofacial teratoma.CONCLUSION Fetal maxillofacial teratomas can be diagnosed by US in early pregnancy,allowing parents to expedite treatment decisions.

Clinical manifestations and the prenatal diagnosis of trisomy 7 mosaicism:Two case reports

BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.

Analysis of the Efficacy of Prenatal B-Ultrasound in Diagnosing Fetal Abnormalities

Objective:To explore the positive significance of using prenatal B-ultrasound in diagnosing fetal abnormalities.Methods:A total of 200 pregnant women who visited Shaanxi Provincial People’s Hospital between January 2023 and January 2024 were recruited as the research subjects.All pregnant women received prenatal examinations.A retrospective analysis was carried out to analyze the positive significance of prenatal B-ultrasound examination in the diagnosis of fetal abnormalities.Results:Prenatal B-ultrasound examination detected 10 cases of fetal abnormalities,with a detection rate of 5.00%.When compared with the postnatal examination results of 5.50%,the difference was insignificant(P>0.05).Moreover,comparing the fetal limb abnormalities and cardiovascular abnormalities in prenatal B-ultrasound examination and postnatal examination,one case of congenital heart disease was missed in the prenatal B-ultrasound examination,and the others were consistent with the postnatal examination results,with a coincidence rate of 90.91%,indicating a high compliance rate.Conclusion:Fetal abnormalities have a great impact on mothers,babies,and families,and it is particularly important to strengthen diagnosis during this process.Prenatal B-ultrasound examination can improve the accuracy of diagnosis of fetal abnormalities and can be promoted in clinical practice as a basis for screening fetal abnormalities.

Prenatal Diagnosis and Management of Fetal Goiter Treated Successfully with Intra-Amniotic Levothyroxine

Goiter is an enlargement of the thyroid gland which can be associated with a number of complications both for the mother and the fetus. A 34-year-old pregnant woman with normal thyroid function was referred to our Department of Obstetrics and Gynecology at Microcitemico Pediatric Hospital, Cagliari, for suspected fetal goiter at 32 gestational weeks. The case was monitored regularly by ultrasound and treated successfully with intra-amniotic levothyroxine (L-T4) administration. Fetal goiter was observed to decrease after this treatment and the thyroid ultrasound findings were also normal both at birth and in subsequent follow-ups. Our case report confirms the feasibility of conservative treatment with L-T4, which can effectively prevent complications related to fetal goiter.

Validity of Different Methods to Prenatal Screening for Down’s Syndrom During First and Second Trimester Pregnancy of Chinese Women

Objective To identify and determine the optimal method to screening for fetal Down＇s syndrome （DS）. Methods Three large cohorts with 17 118, 39 903, 16 646 subjects were enrolled for the first trimester double marker （pregnancy-associated plasma protein A and free [B-human chorionic gonadotropin） screening （FTDMS）, second trimester double marker （c{-fetoprotein and free B-human chorionic gonadotropin） screening （STDMS）, and second trimester triple marker （a-fetoprotein, free 13-human chorionic gonadotropin and unconjugated estriol 3） screening （STTMS）, respectively. The sensitivity, specificity, false positive rate （FPR）, false negative rate （FNR） and the areas under ROC curves （AUCs） were estimated in order to determine the optimal screening method in women under or above 35 years old. Results For women under 35 years old, STTMS was the best method with a detection rate of 68.8% and FPR of 4.3% followed by the STDMS with a detection rate （sensitivity） of 66.7% and FPR of 4.9%. The FTDMS had a lower detection rate of 61.1% and FPR of 6.3%. For women above 35 years old, the detection rate of all the methods was similar, but STTMS method had a lowest FPR of 15.9%. For women under 35 years old AUCs were 0.77 （95% CI, 0.64 to 0.91）, 0.81 （95% CI, 0.71 to 0.91）, and 0.82 （95% CI, 0.69 to 0.96） for FTDMS, STDMS, and STTMS methods, respectively; for those above 35 years old, AUCs were 0.70 （95% CI, 0.56 to 0.83）, 0.70 （95% CI, 0.59 to 0.82）, 0.78 （95% Cl, 0.58 to 0.97） for FTDMS, STDMS and SITMS, respectively. Conclusion Findings from our study revealed that STDMS is optimal for the detection of fetal DS in pregnant women aged under 35. For individual women, if economic condition permits, STFMS is the best choice, while for women aged above 35, STTMS is the best choice in this regard.

Prenatal diagnosis and assessment of congenital spinal anomalies: Review for prenatal counseling

The last two decades have seen continuous advances in prenatal ultrasonography and in utero magnetic resonance imaging. These technologies have increasingly enabled the identification of various spinal pathologies during early stages of gestation. The purpose of this paper is to review the range of fetal spine anomalies and their management, with the goal of improving the clinician's ability to counsel expectant parents prenatally.

Prenatal diagnosis of congenital fetal heart abnormalities and clinical analysis

Objective: To study the value of detecting fetal congenital heart disease (CHD) using the five transverse planes technique of fetal echocardiography. Methods: Nine hundred and eighty-two high-risk pregnancies for fetal CHD were included in this study, the fetal heart was scanned with the five transverse planes technique of fetal echocardiography described by Yagel, autopsy was conducted when pregnancy was terminated. Blood from fetal heart was collected for fetal chromosome analysis. A close follow-up was given for normal fetal heart pregnancies and neonatal echocardiography was performed to check the accuracy of prenatal diagnosis. Results: (1) Forty-six cases (4.68%) were found to have fetal heart abnormalities in this study, 69.56% of them were diagnosed by single four-chamber view, another 30.43% fetal CHD were found by combining other views; (2) Forty-one parents of prenatal fetuses with CHD chose to terminate pregnancy, thirty-two of them gave consent to conduct autopsy, 93.75% of which yielded unanimous conclusion between prenatal fetal echocardiography and autopsy; (3) Thirty-two of 46 cases underwent fetal chromosome analysis, 8 cases (25%) were found to have abnormal chromosome; (4) Five cases were found to have right ventricle and atrium a little bigger than those on the left side, with the unequal condition being the same after birth, but there were no clinical manifestations and they are healthy for the time being; (5) Nine hundred and thirty-six cases were not found with abnormality in this study, but one case was diagnosed with ventricular septal defect after birth, one case was diagnosed with patent ductus arteriosus, one case had atrial septal defect after birth. Conclusions: (1) The detected CHD rate was 4.68% by screening fetal heart with five transverse planes according to Yagel’s description of high risk population basis for CHD. The coinciding rate of prenatal diagnosis and autopsy was 93.75%; (2) The sensitivity of detecting fetal heart abnormality is 92%, the specificity is 99.6% using the five transverse planes technique of fetal echocardiography; (3) Fetuses with mild or moderate disproportion of right and left side in the heart are potentially healthy babies.

Non-invasive Prenatal Diagnosis of Trisomy 21 by Dosage Ratio of Fetal Chromosome-specific Epigenetic Markers in Maternal Plasma

This study examined the methylation difference in AIRE and RASSF1A between maternal and placental DNA, and the implication of this difference in the identification of free fetal DNA in maternal plasma and in prenatal diagnosis of trisomy 21. Maternal plasma samples were collected from 388 singleton pregnancies, and placental or chorionic villus tissues from 112 of them. Methylation-specific PCR （MSP） and methylation-sensitive restriction enzyme digestion followed by fluorescent quantitative PCR （MSRE ＋ PCR） were employed to detect the maternal-fetal methylation difference in AIRE and RASSF1A. Diagnosis of trisomy 21 was established according to the ratio of fetal-specific AIRE to RASSF1A in maternal plasma. Both methods confirmed that AIRE and RASSF1A were hypomethylated in maternal blood cells but hypermethylated in placental or chorionic villus tissues. Moreover, the differential methylation for each locus could be seen during the whole pregnant period. The positive rates of fetal AIRE and RASSF1A in maternal plasma were found to be 78.1% and 82.1% by MSP and 94.8% and 96.9% by MSRE ＋ PCR. MSRE ＋ PCR was superior to MSP in the identification of fetal-specific hypermethylated sequences （P〈0.05）. Based on the data from 266 euploidy pregnancies, the 95% reference interval of the fetal AIRE/RASSF1A ratio in maternal plasma was 0.33-1.77, which was taken as the reference value for determining the numbers of fetal chromosome 21 in 102 pregnancies. The accu-racy rate in 98 euploidy pregnancies was 96.9% （95/98）. Three of the four trisomy 21 pregnancies were confirmed with this method. It was concluded that hypermethylated AIRE and RASSF1A may serve as fetal-specific markers for the identification of fetal DNA in maternal plasma and may be used for noninvasive prenatal diagnosis of trisomy 21.

Enriched environment upregulates growth-associated protein 43 expression in the hippocampus and enhances cognitive abilities in prenatally stressed rat offspring

In our previous study, we reported that prenatal restraint stress could induce cognitive deficits, which correlated with a change in expression of growth-associated protein 43 in the hippocampus. In this study, we investigated the effects of enriched environment on cognitive abilities in prenatally stressed rat offspring, as well as the underlying mechanisms. Reverse transcription-PCR and western blot assay results revealed that growth-associated protein 43 mRNA and protein levels were upregulated on postnatal day 15 in the prenatal restraint stress group. Growth-associated protein 43 expression was significantly lower in the prenatal restraint stress group compared with the negative control and prenatal restraint stress plus enriched environment groups on postnatal days 30 and 50. Morris water maze test demonstrated that cognitive abilities were noticeably increased in rats from the prenatal restraint stress plus enriched environment group on postnatal day 50. These results indicate that enriched environment can improve the spatial learning and memory ability of prenatally stressed offspring by upregulating growth-associated protein 43 expression.

Prenatal diagnosis of choledochal cyst using magnetic resonance imaging: A case report

Choledochal cysts are congenital anomalies of the biliary ducts, characterized by cystic dilatation of the ducts.Prenatal diagnosis of this anomaly using ultrasonography (US) has been well documented. Magnetic resonance imaging (MRI) has recently become an important complement to US in prenatal diagnosis of fetal anomalies. We herein report a patient in whom at 24 wk' gestation US suggested a right upper quadrant abdominal cyst and in whom at 26 wk' gestation MRI more clearly delineated the cyst and its surrounding structures and suggested a choledochal cyst, which was confirmed at postnatal surgery and histopathology.

Estrogen augmented visceral pain and colonic neuron modulation in a double-hit model of prenatal and adult stress

BACKGROUND Chronic stress during pregnancy may increase visceral hyperalgesia of offspring in a sex-dependent way.Combining adult stress in offspring will increase this sensitivity.Based on the evidence implicating estrogen in exacerbating visceral hypersensitivity in female rodents in preclinical models,we predicted that chronic prenatal stress(CPS)+chronic adult stress(CAS)will maximize visceral hyperalgesia;and that estrogen plays an important role in colonic hyperalgesia.AIM The aim was to illuminate the role of estrogen in colonic hyperalgesia and its underlying mechanisms.METHODS We established a CPS plus CAS rodent model in which the balloon was used to distend the colorectum.The single-fiber recording in vivo and patch clamp experiments in vitro were used to monitor the colonic neuron’s activity.The reverse transcription-polymerase chain reaction,western blot,and immunofluorescence were used to study the effects of CPS and CAS on colon primary afferent sensitivity.We used ovariectomy and letrozole to reduce estrogen levels of female rats respectively in order to assess the role of estrogen in female-specific enhanced primary afferent sensitization.RESULTS Spontaneous activity and single fiber activity were significantly greater in females than in males.The enhanced sensitization in female rats mainly came from lowthreshold neurons.CPS significantly increased single-unit afferent fiber activity in L6-S2 dorsal roots in response.Activity was further enhanced by CAS.In addition,the excitability of colon-projecting dorsal root ganglion(DRG)neurons increased in CPS+CAS rats and was associated with a decrease in transient Atype K+currents.Compared with ovariectomy,treatment with the aromatase inhibitor letrozole significantly reduced estrogen levels in female rats,confirming the gender difference.Moreover,mice treated with letrozole had decreased colonic DRG neuron excitability.The intrathecal infusion of estrogen increased brain-derived neurotrophic factor(BDNF)protein levels and contributed to the response to visceral pain.Western blotting showed that nerve growth factor protein was upregulated in CPS+CAS mice.CONCLUSION This study adds to the evidence that estrogen-dependent sensitization of primary afferent colon neurons is involved in the development of chronic stress-induced visceral hypersensitivity in female rats.

Noninvasive Prenatal Testing for Fetal Chromosomal Abnormalities Using Massively Parallel Sequencing: Clinical Experience from 7910 Korean Pregnancies

Objective: The purpose of this study is to review the clinical experience and performance of noninvasive prenatal testing (NIPT) method, using cell-free DNAto detect chromosomes 21, 18, 13, X, and Y abnormalities in over 7910 clinical samples from South Korean population. Method: Pregnant women between 1st of November 2015 to 18th of February 2018, with obstetric clinical findings participated in the study. NIPT was performed based on masivelly parallel sequencing with 0.3× low coverage paired-end sequencing using cell-free DNA in maternal plasma. Further invasive prenatal testing was recommended for pregnant women with positive NIPT results. Results: Of the total 7910 participants, 7890 (99.75%) were tested for NIPT and the remaining 20 (0.25%) were below the Quality Control (QC) standards. T13, T18, XXX, XXY and XYY had 100% of sensitivity, specificity, positive predictive values (PPV) and accuracy. The overall sensitivity was 100% and specificity, PPV and accuracy of all chromosomal abnormalities with further validation were 99.92%, 94.25%, and, 99.92% respectively. Conclusion: Our NIPT results showed high positive predictive value for the detection of autosomal trisomies and sex chromosome aneuploidies in our sample cohort.

Prenatal Playful-Educational Activities, Psycho-Emotional Well-Being of Pregnant Women and Perinatal Outcomes: A Pilot Study

Objective: To present the results of a pilot study that evaluated the psycho-emotional well-being, and the perinatal results of a group of 44 women who attended a prenatal program that incorporates playful and educational activities, in a Child Development Center in Durango. Mexico. Methods: A group of 44 women with informed consent participated for 28 weeks in the prenatal program. The condition of psycho-emotional well-being during the first and third trimesters and the perinatal results were analyzed with validated instruments. Physiological stress was also assessed with salivary cortisol in the same trimesters. Results: More than 90% of the women evaluated their psycho-emotional condition as satisfactory and very satisfactory. The evaluation of anxiety in its Trait/State modalities placed the participants in the category of mild and moderate. Salivary cortisol showed values within a normal range. Perinatal results showed that 98% of deliveries were at term, 93% of newborns weighed more than 2500 grams, and 98% of newborns had an APGAR score of 9 at 5 minutes. Conclusion: The results suggest that the incorporation of playful and educational actions to prenatal surveillance positively influenced the biopsychosocial condition of the pregnant woman and favorable perinatal outcomes.

Noninvasive Prenatal Diagnosis of Fetal Sex by Single-cell PEP-PCR Method

A new method for noninvasive prenatal diagnosis of fetal sex was developed by using single cell PEP PCR techniques. Micromamipulation techniques were used to obtain single fetal cells from 273 maternal blood samples. The genome of single cells was preamplified by PEP and SRY genes were analyzed by PCR method. The SRY genes of 149 samples were detected by the new method among 153 samples carrying male fetus, while 119 out of 120 samples carrying female fetus were proved negative for SRY genes. The sensitivity and specificity of the new method were 97.39 % and 99.17 % respectively and the correct rate was 98.17 %. The new method has the advantage of high sensitivity and specificity in noninvasive prenatal diagnosis of fetal sex and provides the basis of other researches such as sex linked inherited diseases.

Prenatal diagnosis of spinocerebellar ataxia type 3/Machado-Joseph disease in China's Mainland A case report

Spinocerebellar ataxia type 3/Machado-Joseph disease （SCA3/MJD） is a progressive, currently untreatable and ultimately fatal ataxic disorder that belongs to the group of neurological disorders known as CAG-repeat or polyglutamine diseases. Here, we present the first prenatal diagnosis of SCA3/MJD in China's Mainland in a woman who was known to carry an expanded CAG-trinucleotide repeat in the MJD1 gene. After evaluating motivation and psychological tolerance of the couple, amniocentesis was performed after 14 weeks of gestation. Polymerase chain reactions followed by T-vector cloning and direct sequencing were employed to evaluate the CAG-repeat number of the fetal MJD1 gene. We identified a truncated CAG expansion of 78 repeats in the MJD1 gene of the fetus compared with 81 repeats in his mother.