OBJECTIVE: To explore the cause for a twin pregnancy with false negative result for 22q11.2 deletion syndrome by expanded non-invasive prenatal testing (NIPT-plus). METHODS: A pregnant woman with twin pregnancy through in-vitro fertilization and negative result of NIPT-plus was selected as the study subject. Amniocentesis was conducted after ultrasonic finding of fetal abnormalities. In addition to conventional G-banded karyotyping, copy number variation sequencing (CNV-Seq) was used to detect chromosomal microdeletion and microduplication. Clinical data of the woman were analyzed to explore the reasons underlying the false negative result. RESULTS: NIPT-plus has yielded a negative result with 11.77 Mb unique reads and 3.05% fetal fraction. Both fetuses had a normal karyotype (46,XY and 46,XX). CNV-seq indicated that one of the fetuses was normal, whilst the other was diagnosed with a 2.58 Mb deletion in the 22q11.2 region. CONCLUSION The false negative result may be attributed to the combined influence of low fetal fraction, high BMI, twin pregnancy through IVF and a relatively small deletion fragment. Ultrasonography exam following a low-risk result of NIPT-plus should not be neglected.
Pregnancy ; Female ; Humans ; Prenatal Diagnosis ; Pregnancy, Twin/genetics* ; DiGeorge Syndrome/genetics* ; DNA Copy Number Variations ; Amniocentesis

OBJECTIVE: To investigate the relationship between 22q11.2 duplication and clinical phenotype. METHODS: Eight fetuses with 22q11.2 duplication syndrome diagnosed by chromosome microarray analysis (CMA) through amniocentesis from February 2015 to March 2017 were enrolled in the study. The prenatal diagnostic indications, fetal ultrasound, chromosome karyotype, peripheral blood CMA results of parents, pregnancy outcomes and follow-up of postnatal growth and development were retrospectively analyzed. RESULTS: Prenatal serological screening indicated 6 cases with high risk of trisomy 21, 1 case with nuchal fold (NF) thickening and 1 case of maternal chromosomal balanced translocation. Fetal ultrasonography showed 1 case of NF thickening, 1 case of fetal cerebral ventriculomegaly and 6 cases with normal ultrasound. CMA demonstrated that the size of duplication was between 651 kb and 3.26 Mb, and 22q11.2 duplication. Parents' CMA results revealed that 6 cases inherited from one of the parents with normal phenotype, and the parents of 2 cases refused the CMA test. Two couples chose induced labor; 6 cases of continued pregnancy had normal phenotypes at birth. All 6 cases were followed up with longest of 3.5 years. The growth and psychological development were normal in 5 cases, and one case was growth retardation. CONCLUSIONS There were no specific clinical phenotypes in 22q11.2 duplication syndrome, and most of them were inherited from one parent who has normal phenotype.
Abnormalities, Multiple ; diagnosis ; genetics ; Chromosome Duplication ; genetics ; Chromosomes, Human, Pair 22 ; genetics ; DiGeorge Syndrome ; diagnosis ; genetics ; Female ; Humans ; Male ; Pregnancy ; Pregnancy Outcome ; Prenatal Diagnosis ; Retrospective Studies

OBJECTIVETo delineate the phenotypic characteristics of 22q11.2 deletion syndrome and the role of CRKL gene in the pathogenesis of cardiac abnormalities.

METHODSG-banded karyotyping, single nucleotide polymorphism (SNP) array and fluorescence in situ hybridization (FISH) were performed on a fetus with tetralogy of Fallot detected by ultrasound. Correlation between the genotype and phenotype was explored after precise mapping of the breakpoints on chromosome 22q11.2. SNP array was also performed on peripheral blood samples from both parents to clarify its origin.

RESULTSThe fetus showed a normal karyotype of 46,XY. SNP array performed on fetal blood sample revealed a 749 kb deletion (chr22: 20 716 876-21 465 659) at 22q11.21, which encompassed the CRKL gene but not TBX1, HIRA, COMT and MAPK1. Precise mapping of the breakpoints suggested that the deleted region has overlapped with that of central 22q11.2 deletion syndrome. SNP array analysis of the parental blood samples suggested that the 22q11.21 deletion has a de novo origin. The presence of 22q11.21 deletion in the fetus was also confirmed by FISH analysis.

CONCLUSIONCentral 22q11.21 deletion probably accounts for the cardiac abnormalities in the fetus, for which the CRKL gene should be considered as an important candidate.

Adaptor Proteins, Signal Transducing ; genetics ; Adult ; Chromosome Deletion ; Chromosomes, Human, Pair 22 ; genetics ; DiGeorge Syndrome ; diagnosis ; embryology ; genetics ; Female ; Fetal Diseases ; diagnosis ; genetics ; Genotype ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Nuclear Proteins ; genetics ; Phenotype ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo establish a method for the prenatal diagnosis of 22q11 microdeletion syndrome.

METHODSBACs-on-Beads (BoBs) and fluorescence in situ hybridization (FISH) were performed on a fetus for whom amniotic chromosomal culturing has failed and a pair of twin fetuses suspected for 22q11 deletion syndrome.

RESULTS22q11 microdeletion was detected in all 3 fetuses by prenatal BoBs as well as FISH, with only one red signal detected at the DiGeorge/VCFS N25 site and two green signals on the 22q13.3 ARSA site.

CONCLUSIONThe combination of prenatal BoBs and FISH can provide a method for the prenatal diagnosis of 22q11 microdeletion.

Adult ; Chromosome Deletion ; Chromosomes, Human, Pair 22 ; genetics ; DiGeorge Syndrome ; diagnosis ; embryology ; genetics ; Female ; Fetal Diseases ; diagnosis ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo carry out genetic analysis for two patients affected with congenital heart disease, developmental delay with or without cleft palate.

METHODSCytogenetic and molecular genetic methods including karyotyping, fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA) and single nucleotide polymorphisms array (SNP-array) were employed to detect potential mutations. For parents of both patients, MLPA was used to analyze whether they were carrier of the deletion.

RESULTSFor neither patient, no abnormality was detected upon karyotype analysis. However, FISH analysis has indicated the presence of 22q11.2 deletion. SNP-array analysis has confirmed that both patients have carried a 2.5 Mb deletion in the 22q11.2 region. MLPA analysis suggested none of the parents has carried the same deletion.

CONCLUSIONAlthough the phenotypes of our patients were not identical, they were both diagnosed as 22q11.2 deletion syndrome by multiple methods. The deletions in both cases were de novo in nature. Precise delineation of the genotype can facilitate better understanding of the patients' phenotype.

Abnormalities, Multiple ; genetics ; pathology ; Child, Preschool ; Chromosome Deletion ; Chromosomes, Human, Pair 22 ; genetics ; DiGeorge Syndrome ; genetics ; pathology ; Ear, External ; abnormalities ; Genotype ; Humans ; In Situ Hybridization, Fluorescence ; Infant ; Karyotyping ; Male ; Microarray Analysis ; methods ; Phenotype ; Polymorphism, Single Nucleotide ; Syndrome

DiGeorge Syndrome ; genetics ; Humans ; Phenotype ; Twins, Monozygotic

Chromosome Deletion ; Chromosomes, Human, Pair 22 ; DiGeorge Syndrome ; diagnosis ; genetics ; Humans ; Infant ; Male

We report a 32 year-old Chinese lady with history of tetralogy of Fallot, presented to us with chest pain due to hypocalcemia secondary to hypoparathyroidism. With her dysmorphic facial features and intellectual disability 22q11.2 deletion was suspected and confirmed by genetic study. Clinicians should consider the diagnosis of DiGeorge syndrome in adult patient with past medical history of congenital heart disease, facial dysmorphism, intellectual disability and primary hypoparathyroidism.
Adult ; Delayed Diagnosis ; DiGeorge Syndrome ; diagnosis ; genetics ; Female ; Humans ; Hypocalcemia ; diagnosis ; genetics

OBJECTIVETo investigate the clinical features and molecular diagnostic methods of three patients with DiGeorge anomaly.

METHODThe clinical manifestations and immunological features of the three cases with DiGeorge anomaly were analyzed. We detected the chromosome 22q11.2 gene deletion by fluorescence in situ hybridization (FISH).

RESULT(1) CLINICAL MANIFESTATIONS: All three cases had varying degrees of infection, congenital heart disease and small thymus by imaging; two cases had significant hypocalcemia (1.11 mmol/L and 1.22 mmol/L, respectively), accompanied by convulsions; only 1 case had cleft palate and all had no significant facial deformity. (2) Immunological characteristics: All three cases had varying degrees of T-cell immune function defects (percentage of T lymphocytes was 24% - 43%, absolute count was 309 - 803/µl), and levels of immunoglobulin G, A, M, and percent of B lymphocytes and absolute count were normal. (3) Detection of the chromosome 22q11.2 gene deletion: 400 cells of each case were detected. All cells showed two green and one red hybridization signal, indicating the presence of gene deletions in chromosome 22q11.2. (4) OUTCOME: All three cases were treated with thymosin, and appropriate clinical intervention for cardiac malformations, hypocalcemia, and were followed-up for 4 - 18 months, the prognosis was good.

CONCLUSIONDiGeorge anomaly showed diverse clinical manifestations. We should consider the disease if patients had congenital heart disease, thymic hypoplasia, hypocalcemia and/or impaired immune function. FISH for detecting chromosome 22q11.2 gene deletion can be used as accurate and rapid diagnostic method. Thymosin treatment and other clinical intervention may help to improve the prognosis of patients with partial DiGeorge anomaly.

Cells, Cultured ; Chromosome Deletion ; Chromosomes, Human, Pair 22 ; genetics ; DiGeorge Syndrome ; diagnosis ; genetics ; immunology ; Female ; Heart Defects, Congenital ; diagnosis ; genetics ; Humans ; Hypocalcemia ; diagnosis ; genetics ; In Situ Hybridization, Fluorescence ; Infant, Newborn ; Male ; T-Lymphocytes ; immunology ; Thymus Gland ; immunology ; pathology

BACKGROUND: Microdeletion syndromes not detectable by conventional cytogenetic analysis have been reported to occur in approximately 5% of patients with unexplained mental retardation (MR). Therefore, it is essential to ensure that patients with MR are screened for these microdeletion syndromes. Mental retardation syndrome multiplex ligation-dependent probe amplification (MRS-MLPA) is a new technique for measuring sequence dosages that allows for the detection of copy number changes of several microdeletion syndromes (1p36 deletion syndrome, Williams syndrome, Smith-Magenis syndrome, Miller-Dieker syndrome, DiGeorge syndrome, Prader-Willi/Angelman syndrome, Alagille syndrome, Saethre-Chotzen syndrome, and Sotos syndrome) to be processed simultaneously, thus significantly reducing the amount of laboratory work. METHODS: We assessed the performance of MLPA (MRC-Holland, The Netherlands) for the detection of microdeletion syndromes by comparing the results with those generated using FISH assays. MLPA analysis was carried out on 12 patients with microdeletion confirmed by FISH (three DiGeorge syndrome, four Williams syndrome, four Prader-Willi syndrome, and one Miller-Dieker syndrome). RESULTS: The results of MLPA analysis showed a complete concordance with FISH in 12 patients with microdeletion syndromes. CONCLUSIONS: On the basis of these results, we conclude that MLPA is an accurate, reliable, and cost-effective alternative to FISH in the screening for microdeletion syndromes.
*Chromosome Deletion ; Classical Lissencephalies and Subcortical Band Heterotopias/genetics ; DiGeorge Syndrome/genetics ; Humans ; In Situ Hybridization, Fluorescence/*methods ; Laboratories, Hospital ; Mental Retardation/*diagnosis/genetics ; Nucleic Acid Amplification Techniques/*methods ; Prader-Willi Syndrome/genetics ; Williams Syndrome/genetics