With the extensive application of highly sensitive genetic techniques in the field of prenatal diagnosis, prenatal chromosomal mosaicisms including true fetal mosaicisms and confined placental mosaicisms are frequently identified in clinical settings, and the diagnostic criteria and principle of genetic counseling and clinical management for such cases may vary significantly among healthcare centers across the country. This not only has brought challenges to laboratory technician, genetic counselor and fetal medicine doctor, but can also cause confusion and anxiety of the pregnant woman and their family members. In this regard, we have formulated a consensus over the prenatal diagnosis and genetic counseling for chromosomal mosaicisms with the aim to promote more accurate and rational evaluation for fetal chromosomal mosaicisms in prenatal clinics.
Consensus ; Female ; Genetic Counseling ; Humans ; Mosaicism ; Placenta ; Pregnancy ; Prenatal Diagnosis/methods*

PURPOSE: Physicians' attitudes may have a strong influence on women's decision regarding prenatal screening options. The aim of this study is to assess the physicians' attitudes toward prenatal screening for fetal aneuploidy including non-invasive prenatal testing (NIPT) in South Korea. MATERIALS AND METHODS: Questionnaires were distributed and collected at several obstetrics-gynecological conferences and meetings. The questionnaire included 31 multiple choice and 5 fill-in-the-blank questions. Seven questions requested physicians' demographic information, 17 questions requested information about the NIPT with cell-free fetal DNA, and 12 questions requested information about general prenatal screening practices. RESULTS: Of the 203 obstetricians that completed the survey. In contrast with professional guidelines recommending the universal offering of aneuploidy screening, only 53.7% answered that prenatal aneuploidy testing (screening and/or invasive diagnostic testing) should be offered to all pregnant women. Physicians tended to have positive attitudes toward the clinical application of NIPT as both primary and secondary screening methods for patients at high-risk for fetal trisomy. However, for patients at average-risk for fetal trisomy, physicians tended to have positive attitudes only as a secondary screening method. Physicians with more knowledge about NIPT were found to tend to inform their patients that the detection rate of NIPT is higher. CONCLUSION: This is the first study to investigate expert opinion on prenatal screening in South Korea. Education of physicians is essential to ensure responsible patient counseling, informed consent, and appropriate management after NIPT.
Aneuploidy* ; Congresses as Topic ; Counseling ; DNA* ; Education ; Expert Testimony ; Female ; Genetic Testing ; Humans ; Informed Consent ; Korea ; Mass Screening ; Methods ; Practice Patterns, Physicians' ; Pregnant Women ; Prenatal Care ; Prenatal Diagnosis* ; Trisomy

Noonan syndrome (NS) is a genetic disorder caused by autosomal dominant inheritance and is characterized by a distinctive facial appearance, short stature, chest deformity, and congenital heart disease. In individuals with NS, germline mutations have been identified in several genes involved in the RAS/mitogen-activated protein kinase signal transduction pathway. Because of its clinical and genetic heterogeneity, the conventional diagnostic protocol with Sanger sequencing requires a multistep approach. Therefore, molecular genetic diagnosis using targeted exome sequencing (TES) is considered a less expensive and faster method, particularly for patients who do not fulfill the clinical diagnostic criteria of NS. In this case, the patient showed short stature, dysmorphic facial features suggestive of NS, feeding intolerance, cryptorchidism, and intellectual disability in early childhood. At the age of 16, the patient still showed extreme short stature with delayed puberty and characteristic facial features suggestive of NS. Although the patient had no cardiac problems or chest wall deformities, which are commonly present in NS and are major concerns for patients and clinicians, the patient showed several other characteristic clinical features of NS. Considering the possibility of a genetic disorder, including NS, a molecular genetic study with TES was performed. With TES analysis, we detected a pathogenic variant of c.458A > T in KRAS in this patient with atypical NS phenotype and provided appropriate clinical management and genetic counseling. The application of TES enables accurate molecular diagnosis of patients with nonspecific or atypical features in genetic diseases with several responsible genes, such as NS.
Congenital Abnormalities ; Cryptorchidism ; Diagnosis ; Exome* ; Genetic Counseling ; Genetic Heterogeneity ; Germ-Line Mutation ; Heart Defects, Congenital ; Humans ; Intellectual Disability ; Male ; Methods ; Molecular Biology ; Noonan Syndrome* ; Phenotype ; Protein Kinases ; Puberty, Delayed ; Signal Transduction ; Thoracic Wall ; Thorax ; Wills

OBJECTIVE: The current study investigates disease patterns and outcomes in young Israeli epithelial ovarian cancer (EOC) patients and their association with BRCA mutation status. METHODS: Consecutive EOC patients diagnosed at or below 50 years in a single institution between 1995–2011 were identified. All patients are referred for genetic counseling and testing for the predominant Jewish BRCA mutations: BRCA1-185delAG, BRCA1-5382insC, and BRCA2-6174delT. A comparison between BRCA mutation carriers and non-carriers was undertaken across demographic, pathologic, and clinical features; recurrence and survival were compared using the Kaplan-Meier method and associations with the variables of interest were analyzed using the Cox proportional hazards method. RESULTS: One hundred eighty-six patients diagnosed with EOC at 50 years or younger were included, with a total follow-up of 1,088 person years. Mean age at diagnosis was 44±5 years. Of 113 patients with documented BRCA testing, 49.6% carried a germline BRCA mutation, compared with 29% in the general Israeli EOC population (p=0.001). BRCA mutation carriers had a higher rate of serous tumors (75% vs. 64%, p=0.040) and higher CA125 levels at diagnosis (median, 401 vs. 157, p=0.001) than non-carriers. No significant association between BRCA mutations and recurrence (hazard ratio [HR]=1.03; p=0.940) or survival (HR=1.40; p=0.390) was found. CONCLUSION: BRCA mutations are encountered in almost 50% of young Israeli ovarian cancer patients; they are associated with serous tumors and high CA125 levels at diagnosis, but are not independently associated with recurrence or survival in this patient population.
Diagnosis ; Female ; Follow-Up Studies ; Genetic Counseling ; Humans ; Methods ; Neoplasms, Glandular and Epithelial ; Ovarian Neoplasms* ; Prevalence* ; Recurrence ; Young Adult

OBJECTIVETo investigate the genetic cause and prognosis of a fetus with a rare karyotype.

METHODSFluorescence in situ hybridization (FISH) was used for verifying a structural chromosomal abnormality detected by conventional karyotyping analysis. Whole genome DNA microarray was used to analyze copy number variations carried by the fetus.

RESULTSThe fetus was found to have a 46,XX,dup(21)(?q21q22) karyotype, which was verified by FISH analysis as repetition of chromosome 21 region, namely nuc ish 21q22×3. Whole genome DNA microarray confirmed that there was a 17.87 Mb duplication in the 21q21.3q22.3 region, which involved GATA1, JAK2 and ALL genes and spanned the Down syndrome region. The genes are implicated in craniofacial abnormalities, cardiac abnormalities, mental retardation, growth retardation, limb abnormalities. In addition, there was also an 8.43 Mb deletion in the 4p16.1p16.3 region, which involved FGFR3, LETM1, WHSC1 and WHSC2 and other 64 OMIM genes and spanned the Wolf-Hirschhorn syndrome region. The genes are implicated in growth retardation, craniofacial abnormalities, cardiac abnormalities, mental retardation, and hypotonia. After consultation, the family chose to terminate the pregnancy at 25th week of gestation.

CONCLUSIONFISH can help to verify structural chromosome abnormalities suspected by conventional karyotyping analysis. Combined with whole genome microarray, these can determine copy number variation and its region containing the disease genes, and facilitate clinical analysis of the fetus.

Abortion, Eugenic ; Adult ; Chromosome Banding ; Chromosome Deletion ; Chromosome Disorders ; diagnosis ; genetics ; Chromosome Duplication ; Chromosomes, Human, Pair 21 ; genetics ; Chromosomes, Human, Pair 4 ; genetics ; DNA Copy Number Variations ; Female ; Fetal Diseases ; diagnosis ; genetics ; Genetic Counseling ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Pregnancy ; Prenatal Diagnosis ; methods

Constitutional interstitial deletions of the long arm of chromosome 5 (5q) are quite rare, and the corresponding phenotype is not yet clearly delineated. Severe mental retardation has been described in most patients who present 5q deletions. Specifically, the interstitial deletion of chromosome 5q33.3q35.1, an extremely rare chromosomal aberration, is characterized by mental retardation, developmental delay, and facial dysmorphism. Although the severity of mental retardation varies across cases, it is the most common feature described in patients who present the 5q33.3q35.1 deletion. Here, we report a case of a de novo deletion of 5q33.3q35.1, 46,XY,del(5)(q33.3q35.1) in an 11-year-old boy with mental retardation; to the best of our knowledge this is the first case in Korea to be reported. He was diagnosed with severe mental retardation, developmental delay, facial dysmorphisms, dental anomalies, and epilepsy. Chromosomal microarray analysis using the comparative genomic hybridization array method revealed a 16-Mb-long deletion of 5q33. 3q35.1(156,409,412-172,584,708)x1. Understanding this deletion may help draw a rough phenotypic map of 5q and correlate the phenotypes with specific chromosomal regions. The 5q33.3q35.1 deletion is a rare condition; however, accurate diagnosis of the associated mental retardation is important to ensure proper genetic counseling and to guide patients as part of long-term management.
Arm ; Child ; Chromosome Aberrations ; Chromosomes, Human, Pair 5 ; Comparative Genomic Hybridization ; Diagnosis ; Epilepsy ; Genetic Counseling ; Humans ; Intellectual Disability* ; Korea ; Male* ; Methods ; Microarray Analysis ; Phenotype

OBJECTIVETo analyze the genetic characteristics and molecular mechanism of Chinese patients with Rett syndrome (RTT) and assess the recurrent risk in order to provide genetic counseling for the family with RTT patient.

METHODSMethyl-CpG-binding protein 2 (MECP2) gene mutation analysis were performed on 405 Chinese RTT cases and 292 mothers of the patients with MECP2 mutations with polymerase chain reaction (PCR), direct sequencing and multiplex ligation-dependent probe amplification (MLPA). Then cyclin-dependent kinase-like 5 (CDKL5) and forkhead box protein G1 (FOXG1) genes mutation analysis were performed on the patients without MECP2 mutation. Parental origin of mutated MECP2 gene was detected with allele specific PCR analysis. Based on the difference methylation in CpG island of the first exon of human androgen-receptor gene on active and inactive X-chromosomes, methylation sensitive restriction endonuclease digestion was used to analyze the X-chromosome inactive (XCI) patterns.

RESULTSMECP2 gene mutation was found in 86.9% RTT cases. CDKL5 gene mutation was found in only 3 cases with early-onset seizures variant. No FOXG1 mutation was found. There were 94.4% MECP2 mutations of paternal origin,and point mutations were common. However, microdeletions were common in maternal origin mutation. MECP2 gene mutation was found in only 1 (0.34%,1/292) mother with normal phenotype and non-random XCI pattern. Her daughter was a RTT patient with preserved speech variant, and her XCI pattern was random.

CONCLUSIONMECP2 is the main pathogenic gene in RTT. CDKL5 gene should be screened in patients with early-onset seizures variant without MECP2 gene mutation. The majority of RTT patients had paternally derived de novo MECP2 gene mutation, which may explain the high female to male ratio in RTT. Only 0.34% mothers carried the pathogenic mutation, indicating a lower recurrent risk for RTT families. The XCI may modulate the phenotype of RTT, so MECP2 gene mutation screening in the mothers is important for genetic counseling.

Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Child ; Child, Preschool ; Female ; Genetic Counseling ; methods ; Genetic Predisposition to Disease ; Humans ; Methyl-CpG-Binding Protein 2 ; genetics ; Prenatal Diagnosis ; methods ; Rett Syndrome ; genetics ; Young Adult

OBJECTIVETo perform spectral karyotyping (SKY), fluorescence in situ hybridization (FISH) and conventional karyotyping on prenatally detected marker chromosomes and complex chromosomal aberrations.

METHODSFive marker chromosomes and 2 complex chromosome aberrations diagnosed by G banding were collected. SKY was performed to verify the composition of marker chromosomes. FISH was used to confirm the diagnosis when necessary. In certain cases, C or N banding technique was employed to verify the composition of chromosomes. Results of ultrasonography and pregnancy outcome were reviewed.

RESULTSAmong the 5 marker chromosomes, 2 were large and 3 were medium in size, 4 were de novo and one was inherited from the father. By SKY analysis, 2 marker chromosomes have originated from non-acrocentric chromosomes (4 and 9), whilst the other two have originated from acrocentric chromosomes (21 and 22). The remainder was derived from X chromosome. The SKY results were confirmed by FISH in 3 cases. Four cases have chosen to terminate the pregnancy after genetic counseling. A fetus with inherited paternal marker chromosome was delivered at term, and showed normal development during the first year of life. As for the other 2 cases with complex chromosome aberrations, by SKY examination, one had duplication in chromosome 8 and the other had chromosome rearrangements derived from translocation between chromosomes 2 and 6. In the latter case the fetus was delivered at term but showed developmental retardation at 6 months.

CONCLUSIONSKY in combination with FISH can facilitate identification of the origins of marker chromosomes as well as complex chromosomal aberrations. With combined information from ultrasonography, SKY and FISH, effective counseling may be offered to the patients.

Chromosome Aberrations ; Chromosome Banding ; methods ; Chromosome Disorders ; genetics ; Female ; Genetic Counseling ; methods ; Genetic Markers ; genetics ; Humans ; Male ; Pregnancy ; Spectral Karyotyping ; methods

OBJECTIVETo set up thalassemia population intervention model in order to decrease the birth of thalassemia major, relying on population and family planning service system.

METHODSPregnant women and their husbands were educated about thalassemia, and participated in screening and prenatal diagnosis if the couple were carriers of thalassemia in the areas of Huangpu, Panyu, Zengcheng and Tianhe districts of Guangzhou.

RESULTSThe network of thalassemia intervention mainly dependent on family planning service system was set up in these regions. A total of 10 695 families participated in thalassemia screening and 16 thalassemia major fetuses were diagnosed in the last two years. No one was thalassemia major in the 8360 newborn.

CONCLUSIONThalassemia population intervention model was set up relying on family planning service system and it significantly decreased the birth of thalassemia major.

Family Planning Services ; methods ; Female ; Genetic Counseling ; Heterozygote ; Humans ; Infant, Newborn ; Male ; Mass Screening ; methods ; Pregnancy ; Prenatal Diagnosis ; methods ; Spouses ; Thalassemia ; diagnosis ; genetics ; prevention & control

OBJECTIVETo analyze the aberrant der(X) chromosome using conventional and molecular cytogenetic approaches in a fetus of second trimester and to discuss its clinical effect.

METHODSConventional cytogenetic procedures (GTG and CBG banding) were performed on cultured amniotic fluid cells. Three-color fluorescence in situ hybridization (FISH) consisting of X chromosome enumeration probes(CEPX), CEPY and Tel Xp/Yp was further performed to study the aberrant der(X) chromosome.

RESULTSDer(X) was a rare X/Y translocation. The final karyotypes of the fetus was designated as: 46,X,der(X)t(X;Y)(p22.3;q11.2). ish der(X)t(X;Y)(p22.3;q11.2)(X/Ypter-, DXZ1+, DYZ1+)mat.

CONCLUSIONThe combination of FISH and conventional cytogenetic techniques is a powerful tool to determine derivative chromosome and to offer an accurate genetic counseling. Identification of Xp; Yq rearrangement can help estimate the risk of fetus abnormalities and give a more precise prognosis.

Adult ; Amniocentesis ; methods ; Amniotic Fluid ; cytology ; Chromosome Aberrations ; Chromosome Banding ; methods ; Chromosomes, Human, X ; Cytogenetic Analysis ; methods ; Female ; Fetus ; abnormalities ; Genetic Counseling ; methods ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Pregnancy ; Pregnancy Trimester, Second