Prenatal and fetal diagnosis of trisomy 18 after low-risk cell-free fetal DNA screening: A report of four cases.

INTRODUCTION: Non-Invasive Prenatal Screening (NIPS) is a useful screening method for common aneuploidies that can occur in pregnancies. It yields high sensitivities and specificities for the targeted conditions it tests for. Most commonly, these include Trisomies in chromosomes 21, 18, and 13, as well as aneuploidies in chromosomes X and Y. It does not, however, replace diagnostic testing. We review four cases seen by our institutions of patients who had NIPS performed with low-risk results and subsequently had fetuses affected with trisomy 18. METHODS: All fetal samples were evaluated by level II anatomic ultrasound and tested on amniocytes or products of conception through karyotype or chromosomal microarray following low-risk NIPS. RESULTS: None of the fetuses showed evidence of mosaicism and had features (both on ultrasound and postnatally) consistent with Trisomy 18. Postnatal fluorescence in situ hybridization performed on Formalin-Fixed Paraffin-Embedded tissue from 3 of the affected pregnancies' placentas identified mosaicism of trisomy 18. DISCUSSION: We discuss the possible explanations for the discrepancy between NIPS results and fetal karyotype, including, but not limited to placental mosaicism, placental size, and limitations of NIPS as a screening test.

Antenatal Milk Expression as a Lactation Support Intervention for Parents of Infants With Severe Birth Defects: A Case Series.

BACKGROUND: A diet high in parent's own milk (parental milk) is a lifesaving intervention for critically ill infants. Lactating parents whose infants are born with birth defects that require surgical repair (surgical infants) shortly after birth often struggle to initiate and maintain a milk supply that meets their infant's nutritional needs. Antenatal milk expression has been identified as a safe, feasible, and potentially effective strategy that promotes parents' direct chest/breastfeeding or milk expression (lactation) confidence and helps parents attain their lactation goals. Two cases are presented to illustrate the potential for using antenatal milk expression as a lactation support intervention for parents of surgical infants. CASE PRESENTATION: Cases were drawn from a pilot study exploring the feasibility of implementing antenatal milk expression among pregnant parents of surgical infants. Participants were healthy women recruited after 30 weeks of gestation who received a fetal diagnosis of a complex congenital heart defect. Despite variability in clinical course and length of stay, parental milk was provided for the duration of each infant's hospitalization. Participant perceptions of antenatal milk expression varied. CONCLUSION: More research is needed to evaluate the feasibility, efficacy, and parent or provider perceptions of antenatal milk expression as a lactation support intervention for parents of surgical infants.

Reproductive outcomes in individuals with chromosomal reciprocal translocations.

PURPOSE: Patients with reciprocal balanced translocations (RBT) have a risk for recurrent pregnancy losses (RPL), affected child, and infertility. Currently, genetic counseling is based on karyotypes found among the products of conception (POC), although factors influencing the success of assisted reproductive technologies (ART) in RBT couples are not established. METHODS: Cytogenetic results from 261 POC and offspring of the parents (113 women and 90 men) with RBT were evaluated. Chromosome segregation modes and number of euploid embryos were assessed in couples undergoing in vitro fertilization. RESULTS: Patients with translocations involving an acrocentric chromosome have a higher risk of unbalanced gametes caused by a 3:1 segregation. Female RBT patients have a statistically higher risk of aneuploidy due to an interchromosomal effect. The rate of euploid embryos is low due to meiosis I malsegregation of RBT, meiosis II nondisjunction, additional whole chromosome or segmental aneusomies. RBT patients with RPL have a higher rate of miscarriage of euploid fetuses with RBT. CONCLUSION: Chromosome-specific factors, female gender, age, and history of RPL are the risk elements influencing pregnancy and in vitro fertilization success in RBT patients. Chromosomal microarray analysis of POC is necessary to provide an accurate and timely diagnosis for patients with adverse reproductive outcomes.

Beyond Down syndrome phenotype: Paternally derived isodicentric chromosome 21 with partial monosomy 21q22.3.

Inverted isodicentric chromosome 21 is a rare form of chromosomal rearrangement that may result in trisomy 21; sometimes this rearrangement may also lead to segmental monosomy of the terminal long arm of chromosome 21. In this report, we describe the prenatal diagnosis and neonatal follow-up of a child with a paternally derived, de novo isodicentric chromosome 21 and a concurrent ∼1.2 Mb deletion of the 21q22.3 region [46,XX,idic(21)(q22.3)]. This child presented with unusual phenotype of Down syndrome and additional defects including esophageal atresia and tethered cord syndrome. The resulting phenotype in this infant might be a coalescence of the partial trisomy and monosomy 21, as well as homozygosity for idic (21). The utilization of chromosomal microarray in this case enabled accurate characterization of a rare chromosome abnormality, potentially contributes to future phenotype-genotype correlation and produced evidence for a molecular mechanism underlying this rearrangement.

Genotype-phenotype correlation and pregnancy outcomes of partial trisomy 14q: A systematic review.

Over the last decade, several advances in ultrasound techniques, increasing availability of whole genome microarray testing, and overall expansion of our knowledge about the human genome have drastically enhanced our ability to detect chromosomal abnormalities prenatally. Despite that, genotype-phenotype correlation is difficult to establish for many chromosomal aberrations, particularly for those that are rare, as it requires thorough analysis of a significant number of cases. This in turn increases the burden of the obstetric provider to appropriately counsel a patient regarding prognosis and pregnancy options in these complicated situations. Our experience in prenatal diagnosis and management of a fetus with multiple anomalies and partial trisomy for the 14q11-q24.2 prompted a comprehensive analysis of the relevant literature. Although complete non-mosaic trisomy 14 is associated with first trimester miscarriages, partial trisomy 14q is a rare condition with undefined genotype-phenotype correlation, preventing accurate prenatal counseling, and informed decision making. We performed a systematic literature review, that aimed to summarize prenatal and postnatal findings of individual case reports on 51 patients with partial trisomy 14q in order to elucidate genotype-phenotype correlation, and to supply healthcare professionals with recommendation on essential fetal and parental testing for accurate diagnosis, pregnancy outcomes, and proper family counseling. Comparison of the clinical findings among the patients with partial 14q trisomy suggest that the resulting phenotype is likely to be influenced by the extent of the 14q trisomy segment, associated chromosomal imbalances, parental origin of the rearrangement, and dosage of the genes within the imprinted 14q32 cluster. © 2016 Wiley Periodicals, Inc.

Mutations in FKBP10, which result in Bruck syndrome and recessive forms of osteogenesis imperfecta, inhibit the hydroxylation of telopeptide lysines in bone collagen.

Although biallelic mutations in non-collagen genes account for <10% of individuals with osteogenesis imperfecta, the characterization of these genes has identified new pathways and potential interventions that could benefit even those with mutations in type I collagen genes. We identified mutations in FKBP10, which encodes the 65 kDa prolyl cis-trans isomerase, FKBP65, in 38 members of 21 families with OI. These include 10 families from the Samoan Islands who share a founder mutation. Of the mutations, three are missense; the remainder either introduce premature termination codons or create frameshifts both of which result in mRNA instability. In four families missense mutations result in loss of most of the protein. The clinical effects of these mutations are short stature, a high incidence of joint contractures at birth and progressive scoliosis and fractures, but there is remarkable variability in phenotype even within families. The loss of the activity of FKBP65 has several effects: type I procollagen secretion is slightly delayed, the stabilization of the intact trimer is incomplete and there is diminished hydroxylation of the telopeptide lysyl residues involved in intermolecular cross-link formation in bone. The phenotype overlaps with that seen with mutations in PLOD2 (Bruck syndrome II), which encodes LH2, the enzyme that hydroxylates the telopeptide lysyl residues. These findings define a set of genes, FKBP10, PLOD2 and SERPINH1, that act during procollagen maturation to contribute to molecular stability and post-translational modification of type I procollagen, without which bone mass and quality are abnormal and fractures and contractures result.

Prenatally diagnosed 17q12 microdeletion syndrome with a novel association with congenital diaphragmatic hernia.

We describe the first reported case of a prenatally diagnosed and recently described 17q12 microdeletion syndrome. The fetus was noted to have a congenital diaphragmatic hernia (CDH), echogenic kidneys and cystic left lung on prenatal ultrasound. The patient underwent amniocentesis which resulted in a normal fluorescence in-situ hybridization and karyotype. An oligonucleotide microarray was then performed which demonstrated a 1.4-Mb deletion within the 17q12 region. The deletion caused haploinsufficiency for 17 genes, including AATF, ACACA, DDX52, DUSP14, GGNBP2, HNF-1B, LHX1, PIGW, SYNRG, TADA2A, and ZNHIT3. The deleted region on 17q12 is similar in size and gene content to previously reported 17q12 microdeletion syndromes, which have a minimal critical region of 1.52 Mb. The newly described 17q12 microdeletion syndrome has been associated with MODY5 (maturity-onset of diabetes of the young type 5), cystic renal disease, pancreatic atrophy, liver abnormalities, cognitive impairment and structural brain abnormalities. CDH has not been previously described with the 17q12 microdeletion syndrome. We hypothesize that CDH is part of the spectrum of this syndrome and likely not detected postnatally due to high prenatal mortality.

TFAP2A mutations result in branchio-oculo-facial syndrome.

Branchio-oculo-facial syndrome (BOFS) is a rare autosomal-dominant cleft palate-craniofacial disorder with variable expressivity. The major features include cutaneous anomalies (cervical, infra- and/or supra-auricular defects, often with dermal thymus), ocular anomalies, characteristic facial appearance (malformed pinnae, oral clefts), and, less commonly, renal and ectodermal (dental and hair) anomalies. The molecular basis for this disorder is heretofore unknown. We detected a 3.2 Mb deletion by 500K SNP microarray in an affected mother and son with BOFS at chromosome 6p24.3. Candidate genes in this region were selected for sequencing on the basis of their expression patterns and involvement in developmental pathways associated with the clinical findings of BOFS. Four additional BOFS patients were found to have de novo missense mutations in the highly conserved exons 4 and 5 (basic region of the DNA binding domain) of the TFAP2A gene in the candidate deleted region. We conclude BOFS is caused by mutations involving TFAP2A. More patients need to be studied to determine possible genetic heterogeneity and to establish whether there are genotype-phenotype correlations.

Genotype-phenotype analysis of the branchio-oculo-facial syndrome.

Branchio-oculo-facial syndrome (BOFS; OMIM#113620) is a rare autosomal dominant craniofacial disorder with variable expression. Major features include cutaneous and ocular abnormalities, characteristic facies, renal, ectodermal, and temporal bone anomalies. Having determined that mutations involving TFAP2A result in BOFS, we studied a total of 30 families (41 affected individuals); 26/30 (87%) fulfilled our cardinal diagnostic criteria. The original family with the 3.2 Mb deletion including the TFAP2A gene remains the only BOFS family without the typical CL/P and the only family with a deletion. We have identified a hotspot region in the highly conserved exons 4 and 5 of TFAP2A that harbors missense mutations in 27/30 (90%) families. Several of these mutations are recurrent. Mosaicism was detected in one family. To date, genetic heterogeneity has not been observed. Although the cardinal criteria for BOFS have been based on the presence of each of the core defects, an affected family member or thymic remnant, we documented TFAP2A mutations in three (10%) probands in our series without a classic cervical cutaneous defect or ectopic thymus. Temporal bone anomalies were identified in 3/5 patients investigated. The occurrence of CL/P, premature graying, coloboma, heterochromia irides, and ectopic thymus, are evidence for BOFS as a neurocristopathy. Intrafamilial clinical variability can be marked. Although there does not appear to be mutation-specific genotype-phenotype correlations at this time, more patients need to be studied. Clinical testing for TFAP2A mutations is now available and will assist geneticists in confirming the typical cases or excluding the diagnosis in atypical cases.

Fetal diagnosis and treatment of craniomaxillofacial anomalies.

So many advances in health care are built on the evolution of technology. In the case of fetal medicine, technology has availed an entirely new patient. Advances in prenatal imaging allow us to see and diagnose disease not previously appreciated. Armed with this information, clinicians can better plan for the delivery of the neonate such that any identified anomalies are optimally managed, and the impact on the neonate's health minimized. The oral and maxillofacial surgeon can be a key member in this team by offering expertise in the management of craniomaxillofacial anomalies including congenital tumors, facial clefts, craniosynostosis, micrognathia, and other congenital abnormalities. The techniques for perinatal care of the patient with craniofacial abnormalities continue to evolve as the technology improves. The review of the cases presented at the University of Pittsburgh Fetal Diagnosis and Treatment Team during the past 6 years has shown many opportunities for craniomaxillofacial prenatal evaluation. We describe our recent experience and some of the more common abnormalities with their management considerations that may be encountered by the oral and maxillofacial surgeon on the fetal diagnosis and treatment team.

Critical congenital heart disease--utility of routine screening for chromosomal and other extracardiac malformations.

Objective. Infants with critical congenital heart disease (CHD) can have genetic and other extracardiac malformations, which add to the short- and long-term risk of morbidity and perhaps mortality. We sought to examine our center's practice of screening for extracardiac anomalies and to determine the yield of these tests among specific cardiac diagnostic categories. Design. Retrospective review of infants admitted to the cardiac intensive care unit with a new diagnosis of CHD. Subjects were categorized into six groups: septal defects (SD), conotruncal defects (CTD), single-ventricle physiology (SV), left-sided obstructive lesions (LSO), right-sided obstructive lesions (RSO), and "other" (anomalous pulmonary venous return, Ebstein's anomaly). Screening modalities included genetic testing (karyotype and fluorescent in situ hybridization for 22q11.2 deletion), renal ultrasound (RUS), and head ultrasound (HUS). Results. One hundred forty-one patients were identified. The incidence of cardiac anomalies was: CTD (36%), SD (18%), SV (18%), LSO (14%), RSO (3%), and "other" (8%). Overall 14% had an abnormal karyotype, 5% had a deletion for 22q11.2, 28% had an abnormal RUS and 22% had abnormal HUS. Patients in SD and SV had the highest incidence of abnormal karyotype (36% and 17%); 22q11.2 deletion was present only in CTD and LSO groups (9% and 7%, respectively); abnormal RUS and HUS were seen relatively uniformly in all categories. Premature infants had significantly higher incidence of renal 43% vs. 24%, and intracranial abnormalities 46% vs. 16%. Conclusion. Infants with critical CHD and particularly premature infants have high incidence of genetic and other extracardiac anomalies. Universal screening for these abnormalities with ultrasonographic and genetic testing maybe warranted because early detection could impact short and long-term outcomes.

Single umbilical artery: what does it mean for the fetus? A case-control analysis of pathologically ascertained cases.

PURPOSE: To ascertain the frequency of chromosomal and other anomalies in fetuses with single umbilical artery. METHODS: Placentas with single umbilical artery were identified from hospital pathology laboratory records. For each identified case, the next consecutive placenta with two umbilical arteries served as a control. Pathology records, maternal histories, and prenatal ultrasounds when available were reviewed for congenital anomalies, pregnancy complications, and maternal characteristics. When indicated, placental specimens, amniocytes, or neonatal bloods were karyotyped. RESULTS: Single umbilical artery existed in 2.0% (97/4846) of pathological specimens. Fetuses with single umbilical artery had significantly more chromosomal (10.3% vs. 1.0%) and other congenital anomalies (27% vs. 8%). CONCLUSIONS: The high incidence of major chromosomal and congenital anomalies justifies detailed fetal ultrasonography, echocardiography, and amniocentesis for karyotype when single umbilical artery is discovered during routine ultrasound.