Enlarged cavum septi pellucidi Z-scores in fetuses with trisomy 18.

OBJECTIVE: We aim to establish a formula calculating the fetal cavum septi pellucidi (CSP) width Z-scores and compare CSP width between the normal fetus and 18-trisomy fetus. METHODS: In this retrospective study, 608 normal fetuses and 71 fetuses with the 18-trisomy syndrome were included. Z-scores were calculated after the acquisition of CSP images. Normal CSP width Z-scores formulae were constructed based on gestational age (GA) by performing a standard regression analysis followed by weighted regression of absolute residual values. Subsequently, the Mann-Whitney U test was used to compare the CSP width Z-scores between normal and 18-trisomy groups. RESULTS: Formulae calculating CSP width Z-scores were constructed. Normal fetal CSP width was significantly correlated with GA (R2 = 0.50, p < .01). In 18-trisomy group, 69% (34/49) fetuses displayed enlarged fetal CSP width and CSP width Z-scores (p < .01). CONCLUSIONS: The CSP width Z-scores formulae established in the current study can provide a quantitative basis for the prenatal diagnosis of 18-trisomy syndrome. Enlarged CSP width Z-score may serve as a novel prenatal diagnostic marker for the 18-trisomy syndrome.

[Retrospective Analysis of Hematological Phenotypes in Patients with Gene Mutation and Deletion α-Thalassemia].

OBJECTIVE: To explore the differences between hematological phenotypes of patients with different genotypes in gene mutations and deletion α- thalassemia. METHODS: By screening the α- thalassemia gene test results in the First Affiliated Hospital, Sun Yat-Sen University from January 2015 to April 2020, the patients with mutation and deletion α- thalassemia were obtained, then the differences between hematological phenotypes of patients with different genotypes were analyzed. RESULTS: There were 96 patients with mutation combined with deletion α- thalassemia from the results of 24 054 α- thalassemia patients screened out, including 79 patients with non-deletion Hb H disease (αTα/--SEA) and 17 patients with mild α- thalassemia (αTα/-α), the incidence was 0.42%. Except the number of red blood cells (RBC) and mean corpuscular volume (MCV), the hemoglobin (Hb) concentration, hematocrit (Ht), average red blood cell hemoglobin concentration (MCHC), average red blood cell hemoglobin amount (MCH), average red blood cell volume (MCV) of the patients with αTα/--SEA genotype were significantly lower than those with αTα/-α genotype. The Hb of the patients with αCSα/--SEA and αQSα/--SEA genotype was (86±20)g/L and (84±9)g/L, respectirely, which was significantly lower than (114±16) g/L of αWSα/--SEA genotype (P<0.05); The MCHC of patients with αCSα/--SEA and αQSα/--SEA genotype was (278.8±8.5) g/L and (282.1±21.1)g/L, respectirely, which was also significantly lower than (315.4±19.5) g/L of αWSα/--SEA genotype (P<0.05); There was no significant difference between the patients with αCSα/--SEA and αQSα/--SEA genotype in hematological phenotypes. Except MCH and MCV, there was no significant differences between the patients with αWSα/--SEA and αTα/-α genotype in RBC, Hb, and Ht. The result of Hb A2 was (2.3±0.9)% for only 27 patients who performed electrophoretic analysis. There was no significant difference between the patients with αTα/--SEA and αTα/-α genotype in Hb A2, aslo among 3 types of the patients with αTα/--SEA genotype. CONCLUSION: The hematological phenotype changes caused by αWSα/--SEA genotype are similar to those of mild α- thalassemia, and both of them are significantly lighter than those patients with αCSα/--SEA and αQSα/--SEA genotype.

Discordant intrauterine transfusion in dichorionic twin pregnancy with Rh isoimmunization.

Discordant intrauterine transfusion (IUT) in twin pregnancy with Rh isoimmunization is uncommon and complicated. We report a gravida 3, para 2 woman with a dichorionic diamniotic (DCDA) twin pregnancy and two fetuses received discordant transfusions. Middle cerebral artery peak systolic velocity (MCA-PSV) was used to evaluate the anemic degree in each foetus. IUT was performed 3 times in twin A and 4 times in twin B to reverse foetal anaemia. Transfusions were distinct due to the different tolerance to IUT, and the procedure could be continued in one foetus even if the other one underwent complications. Two male babies were born at 36 weeks of gestation and were given different treatments after birth. Twins were subsequently healthy after 2 years of follow up. The discordant IUT was due to the different tolerance to transfusion in the DCDA twins. Zygosity is important for the management and treatment of haemolytic anaemia in twin pregnancies.

Prenatal diagnosis of submicroscopic chromosomal aberrations in fetuses with ventricular septal defects by chromosomal microarray-based analysis.

OBJECTIVES: To evaluate the usefulness of chromosomal microarray analysis in fetuses with ventricular septal defects (VSDs) with or without associated anomalies and normal karyotype. METHODS: Fetuses with VSDs and normal karyotypes were investigated by using an Affymetrix CytoScan HD array. The cases were classified as isolated or nonisolated VSDs. RESULTS: Among the 52 VSD fetuses, 22 (42.3%) had isolated defects and 30 (57.7%) had additional other ultrasound anomalies. Twenty-six CNVs were identified in 18 fetuses (34.6%), 15 benign CNVs were detected in 11 (21.2%) fetuses, and 8 pathogenic CNVs were detected in 6 (11.5%) fetuses. After excluding 2 fetuses with 22q11.2 deletion syndrome, the rate of pathogenic CNVs was 7.7%. The proportion of variants of unknown significance was 5.8% (3/52). In five cases, additional malformations were detected after birth or abortion, and one case had a prenatal isolated VSD. The detection rate of pathogenic CNVs in nonisolated VSDs was nonsignificantly higher than that in prenatal or postnatal isolated VSDs (4.5%, 1/22 vs 16.7%, 5/30, P = 0.226; 0/21 vs 19.4%, 6/31, P = 0.07). CONCLUSIONS: The results demonstrated the value of chromosomal microarray analysis in the prenatal diagnosis of VSDs. The complexity of other defects enhanced the frequency of pathogenic CNVs, although the results were not significantly different. © 2016 John Wiley & Sons, Ltd.

Cognitive impairment in native Chinese with spinocerebellar ataxia type 3.

BACKGROUND: Previous studies have shown cognitive impairment in patients with spinocerebellar ataxia type 3 (SCA3). However, there is a lack of data on Chinese patients with SCA3. METHOD: We investigated 22 native Chinese with SCA3 and 18 controls matched for age, education as well as mental status. Cognitive assessments were carefully carried out to measure verbal fluency, memory, attention, executive function, visuospatial and visuoconstructive functions. RESULTS: The most common impairments of cognition in native Chinese with SCA3 were disruption of phonemic verbal fluency and frontal executive dysfunction. Deficits in semantic fluency were detected in about 31.8% patients. Impaired visuospatial function and verbal memory were also found in native Chinese with SCA3. The degree of ataxia, CAG repeat length and education were found to correlate with cognitive performance. Multivariate binary logistic regression suggested that an oculomotor disorder and depression are predictors of cognitive impairment. CONCLUSION: Native Chinese with SCA3 had cognitive impairment of frontal executive function, temporal and parietal functions. An oculomotor disorder might be an index of cognitive dysfunction.

[Expression and methylated regulation of HERVWE1 in placenta of monozygotic discordant twins].

OBJECTIVE: To explore the HERVWE1 gene expression in the placentas of discordant monozygotic twins and identify its regulation by methylation. METHODS: Fetuses from 21 pairs of monozygotic discordant twins were marked as "smaller" or "larger" according to birth weight. Placental HERVWE1 mRNA and protein expression profiles were analyzed by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) stain. Methylation profiles of the HERVWE1 promoter region were analyzed by COBRA, MSP-PCR and pyrosequencing assay. RESULTS: In discordant twins group, the mean methylation level of the HERVWE1 promoter region decreased in smaller fetuses (P < 0.05). And there were increased mRNA and protein levels of HERVWE1 in smaller fetuses versus larger counterparts (P < 0.05). CONCLUSION: In discordant monozygotic twins, the HERVWE1 expression is higher in smaller fetuses and lower in larger counterparts. Methylation of HERVWE1 gene promoter region may participate in the regulation of HERVWE1 gene expression in twins.

Imprinting and Promoter Usage of Insulin-Like Growth Factor II in Twin Discordant Placenta.

Case reports from infant twins suggest that abnormal genomic imprinting may be one of the important causes of twin discordance, but it is unknown whether abnormal genomic imprinting occurs in the placenta. Therefore, we sought to determine the relationship between the imprinting of insulin-like growth factor II (IGF-II) in placenta and twin discordance. We analyzed the imprinting and promoter usage of IGF-II in placenta of normal twins (T0 group), weight discordance (T1 group), and phenotype discordance (T2 group). We found the incidence of loss of imprinting (LOI) for IGF-II was higher in the T2 group than that in the T0 and T1 groups, while there was no difference between T0 and T1 groups. The transcripts of promoter 3 were lower in the T2 group than in the T0 and T1 groups, and lower in the twin placenta with LOI than in those with normal imprinting. Our findings indicate that the promoter 3 specific LOI of the IGF-II gene may be closely related with phenotype discordance, not weight discordance.

[Prenatal diagnosis of achondroplasia].

OBJECTIVE: To diagnose achondroplasia prenatally by FGFR3 gene detection. METHODS: Seventy-eight fetuses affected by short-limb dysplasias were recruited. Umbilical blood sampling was employed to obtain fetal blood for karyotyping and FGFR3 gene detection. Genomic DNA was extracted, and the exon 10 of the FGFR3 gene was amplified. PCR amplicons were analyzed by DNA sequencing and restriction fragment length polymorphism with Bfm I. The FGFR3 exon 10 from the parents of the positive fetuses was screened by the same method. RESULTS: In 78 fetuses affected with short-limb dysplasias, 8 cases had G1138A heterozygotic mutation and normal karyotype, and were diagnosed as achondroplasia. The other 70 fetuses had normal nucleotide at nucleotide 1138 in exon 10 of FGFR3, therefore were excluded from achondroplasia. Only one father in parents of the 8 achondroplasia fetuses also had the G1138A mutation. CONCLUSION: Achondroplasia could be diagnosed prenatally in the fetuses affected with short-limb dysplasias by using PCR-RFLP and DNA sequencing of the exon 10 of the FGFR3 gene.

[Clinical study and prenatal diagnosis of fetus with shortened long bones].

OBJECTIVE: To investigate the manifestations and prenatal diagnosis of the fetus with shortened long bones. METHODS: Ultrasonography was conducted on 57 fetuses with shortened long bones and 62 normal fetuses. Percutaneous umbilical blood sampling was performed on the 57 cases to undergo examination of karyotype and mutation in exon 10 of fibroblast growth factor receptor (FGFR)3 gene. Fetal radiography and autopsy were performed in 30 abnormal induced fetuses. RESULTS: Among the 57 fetuses of the shortened long bones group 21 (37%) were diagnosed as with specific skeletal dysplasia postnatally, abnormal chromosome were found in 8 (14%), 4 (7%) were with fetal growth restriction, and 24 (42%) were with unknown etiology. Prenatal ultrasonography showed that in the fetuses with skeletal dysplasia the value of standard deviation score (SD) for femur length and/or humerus length fell to -4 SD of the corresponding pregnancy week, and increase of biparietal diameter was often found; in the fetuses with abnormal chromosome and fetal growth restriction (FGR) the degree of bone shortening was between -2 SD to -4 SD; and in the fetuses with lethal skeletal dysplasia the long bones were shortened at the degree more than -8 SD. When the ratio of femur length to abdominal circumference was less than 0.16, the sensitivity and specificity for predicting narrow thorax were 100% and 85.7% respectively. CONCLUSION: The causes of fetus with shortened long bones include abnormal chromosome, skeletal dysplasia, and FGR. Femur length and/or humerus length falls below -4SD is almost an indication for skeletal abnormality. When the SD is between -2SD and -4SD, chromosome analysis is necessary and regular ultrasonography is recommended. When the femur length and/or humerus length is below -8SD and femur length/abdominal circumference (FL/AC) is less than 0.16, lethal skeletal dysplasia is suspected.

[Relationship between the genotype and hematologic characteristics in the fetuses with thalassemia].

OBJECTIVES: To investigate the relationship between the genotype and the hematologic characteristics in the fetuses with different types of thalassemia. METHODS: Fetal blood samples were taken by cordocentesis, and hemograms from 572 fetuses at the gestational age of 18 to 38 weeks were examined. According to the genotypes of thalassemia, there were 117 fetuses with heterozygous alpha-thalassemia-1, and 60 with homozygous alpha-thalassemia-1. Twenty had beta-thalassemia mild, and 9 had beta-thalassemia major, respectively. The hematological parameters in these groups were compared with reference group in which 366 cases were included. RESULTS: In alpha-thalassemia groups, hemoglobin (Hb), hematocrit (HCT), mean cell volume (MCV), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) significantly decreased (P < 0.001), but in heterozygous alpha-thalassemia-1, red blood cell (RBC) increased. In homozygous alpha-thalassemia-1, RBC decreased significantly (P < 0.001), but white blood cell and nucleated erythrocyte increased (P < 0.001). There were no significant differences between beta-thalassemia and reference group in most hematological parameters except for decrease of MCHC. CONCLUSIONS: In the fetal period, the hemogram of the fetuses with alpha-thalassemia changes significantly, while it does not change in beta-thalassemia. For the couple with heterozygous alpha-thalassemia, hemogram can provide some information for prenatal screening and diagnosis for those fetuses with alpha-thalassemia, especially for homozygous, but genotype detection is necessary for confirming the diagnosis.