Preimplantation Genetic Diagnosis T he opportunity to exclude in-vitro derived embryos with documented genetic abnormalities before the initiation of pregnancy is an attractive means of preventing heritable genetic disease. Currently couples who are carriers of genetic disease have the option of undergoing chorionic villus sampling in the first trimester or amniocentesis in the second trimester...

OBJECTIVE To examine the significance of fetal nuchal translucency at 10-14 weeks' gestation in the prediction of abnormal fetal karyotype. DESIGN Prospective screening study. SETTING The Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London. SUBJECTS 827 fetuses undergoing first trimester karyotyping by amniocentesis or chorionic villus sampling. MAIN OU...

OBJECTIVE In women with hyperglycemia due to heterozygous glucokinase (GCK) mutations, the fetal genotype determines its growth. If the fetus inherits the mutation, birth weight is normal when maternal hyperglycemia is not treated, whereas intensive treatment may adversely reduce fetal growth. However, fetal genotype is not usually known antenatally, making treatment decisions difficult. HIST...

We present here an analysis of 888 unrelated beta-thal chromosomes consisting of 444 transfusion dependent children from various regions of Punjab and Islamabad Pakistan. By using Multiplex ARMS- PCR, restriction endonuclease analysis, allele specific oligonucleotide (ASO) hybridization and sequencing, 17 beta-thal mutations and 3 Hb variants were detected in 99.5 % (884/888) of the chromosomes...

Risk of procedure-related pregnancy loss is currently widely quoted in the UK as 1% for amniocentesis and 1.5% for chorionic villus sampling. Published data suggest that these risk figures are out of date and inaccurate, and that new guidelines are required for pre-test counseling. It is our opinion that accurate and evidence-based information concerning miscarriage risk is vital when counselin...

Invasive methods for prenatal diagnosis include chorionic villus sampling (CVS) and amniocentesis that entail the risk of fetal loss and mortality. During pregnancy, fetal cells including fetal DNA crossed the placenta and within maternal peripheral blood those valuable sources of the sex and genetics information fetuses. It is demonstrated fetal DNA in plasma and serum from healthy pregnant wo...

Noninvasive prenatal testing (NIPT) and direct karyotyping of cytotrophoblast were normal for a male fetus, but cultured chorionic villus mesenchymal cells and umbilical cord fibroblasts showed nonmosaic trisomy 18. This observation provides direct evidence for the cytotrophoblastic origin of cell-free fetal DNA and yields a biological explanation for falsely reassuring NIPT results.

INTRODUCTION recent studies have proposed the introduction of cell-free fetal DNA testing (NIPT-Non Invasive Prenatal Testing) in routine clinical practice emphasizing its high sensibility and specificity. In any case, false positive and false negative findings may result from placental mosaicism, because cell-free fetal DNA originates mainly from placenta. CASE WE REPORT SIX CASES OF WOMEN W...

Isochromosome (tetrasomy) 9p is a rare chromosomal aberration characterized by phenotypic abnormalities ranging from mild developmental delay to multiple anomalies including intrauterine growth retardation, cerebral ventriculomegaly, dysmorphic facial features, cleft lip or palate, abnormal genitalia and renal anomalies. We present a patient with isochromosome (tetrasomy) 9p mosaicism who is a ...

The introduction of new technologies has dramatically changed the current practice of prenatal screening and testing for genetic abnormalities in the fetus. Expanded carrier screening panels and non-invasive cell-free fetal DNA-based screening for aneuploidy and single-gene disorders, and more recently for subchromosomal abnormalities, have been introduced into prenatal care. More recently intr...