Major Chromosomal Abnormalities Research Articles

Neurodevelopment Outcomes in Very-Low-Birth-Weight Infants with Metabolic Bone Disease at 2 Years of Age.

Metabolic bone disease (MBD) predominantly affects preterm infants, particularly very-low-birth-weight (VLBW) infants weighing <1500 g. However, there are limited reports on MBD and neurodevelopmental outcomes. This study aimed to analyze the risk factors for MBD and understand its impact on neurodevelopmental outcomes at 2 years of corrected age. Overall, 749 VLBW infants weighing <1350 g at birth were enrolled. Exclusion criteria were major congenital abnormalities, chromosomal abnormalities, and loss of follow-up on the Bayley Scales of Infant Development, Third Edition (BSID-III) test at 24 months of corrected age. Infants were retrospectively assessed by a trained case manager using the BSID-III test at 6, 12, and 24 months old. Infants were categorized as with or without MBD according to radiographic signs. Of those enrolled, 97 VLBW infants were diagnosed with MBD, compared to 362 VLBW infants without MBD. The proportion of infants that completed three follow-ups was 86%. At the assessment at 2 years of age, infants with MBD had lower and more significant differences in motor, language, and cognitive composites. MBD is associated with poor neurodevelopmental outcomes in cognitive, motor, and language composites for VLBW infants at 24 months of corrected age.

Genetic and Cytometric Characteristics of Pediatric B-Other Acute Lymphoblastic Leukemia Cohort

Background: According to WHO-HAEM5, the majority of precursor B-cell acute lymphoblastic leukemia (B-ALL) cases are classified based on cytogenetic testing according to ploidy changes or well-known chromosomal rearrangements. Approximately 30% of patients with B-ALL, however, display none of the major chromosomal abnormalities. This population is classified together as B-other-ALL, a highly diverse subgroup with heterogenous genetic profiles, clinical characteristics, and outcomes. Recent advances in gene expression profiling and sequencing allowed to identify multiple genetic drivers that confer distinct clinical and prognostic features in B-other ALL resulting in better understanding of this subgroup. Among them, B-ALL with specific gene expression signatures (i.e. BCR-ABL1-like and ETV6-RUNX1-like) have been described and included in the classification. However, due to the complex mechanisms underlying the phenotype, standard molecular and cytogenetic workup is not sufficient to make a diagnosis and there is still no universally accepted definition or diagnostic algorithm. Therefore, there is a need to improve our understanding of genetic aberrations driving B-other ALL, screen for unknown lesions, and associate these findings with clinical picture. Aims: Genetic and cytometric characteristics of pediatric B-other ALL cohort treated in a single center in Poland to evaluate population frequencies of known ALL subtypes, genetic aberrations, immunophenotypes, and evaluate their associations with outcome and clinical and demographic parameters. Methods The study included 54 consecutive children (aged 1-18 years) diagnosed in 2014-2022 with B-other ALL, i.e. excluding hyperdiploidy, hypodiploidy, ETV6-RUNX1, BCR-ABL1, TCF3-PBX1, and KMT2A-fusions. In all samples, targeted RNA sequencing using FusionPlex Acute Lymphoblastic Leukemia library preparation kit (ArcherDx) and digital MLPA using SALSA digital MLPA assay were performed. The samples were sequenced on Illumina MiSeq platform. RNAseq data were analyzed using Archer Analysis software v7.0 and aimed to identify fusions, point mutations and expression levels in 81 genes, including fusion transcripts with unknown partners. MLPA data were analyzed using Coffalyser digitalMLPA software. All novel in-frame fusion transcripts were confirmed with Sanger sequencing. Cytometric evaluation included both standard and extended panel of immunophenotypic markers, i.e. CD45, CD3, CD19, CD34, HLA-DR, phospho-TYR, phospho-STAT3, phospho-STAT5, phospho-CRKL, CRLF2 CD127, CD115, CD25, SOCS1, BLNK, CD97, CD99, CD140A, CD140B, and viability stains (FVS780 and/or 7AAD). Clinical data was obtained retrospectively from medical records. Results: The cohort included 35% of BCR-ABL1-like cases, 2% ETV6-RUNX-like, and 5,5% PAX5 rearranged (1 fusion, 2 mutations). Mutations activating RAS/RAF-MAPK signaling were observed in 64% of cases and spread across all subtypes. JAK-STAT class aberrations were observed in 37% cases whereas ABL-class aberrations - in 7,2%. Three novel in-frame fusion transcripts were detected, including two lesions affecting cytokine/kinase signaling related to BCR-ABL1-like phenotype (TCOF3/PDGFRB and CD74/PDGFRB) and one affecting DNA repair mechanisms (SSBP2/CHD1). Novel aberrations were associated with poor prognosis. In addition, HOOK3/FGFR1 fusion transcript previously described for other hematological malignancies, but not in ALL, was detected in a single subject. Except for CRLF2, none of the single markers alone allowed to distinguish new subtypes of ALL. However, multiparameter statistical analysis of the data allowed to build a Ph-like ALL predictor for the identification of Ph-like ALL cases Conclusion: Our study shows population-based frequencies of novel ALL subtypes, including both recurrent and novel genetic aberrations. This data widens our knowledge on the interplay between molecular aberrations and clinical course of the disease and provides clues for diagnostics optimization.

High-Dose Docosahexaenoic Acid in Newborns Born at Less Than 29 Weeks’ Gestation and Behavior at Age 5 Years

Children born at less than 29 weeks' gestation are at risk of behavioral difficulties. This may be due in part to the lack of transplacental supply of docosahexaenoic acid (DHA), a key fatty acid with structural and functional roles in the brain. To determine whether meeting the neonatal DHA requirement through supplementation is associated with improved behavioral functioning of children born at less than 29 weeks' gestation. This was a follow-up of children from 10 Australian participating centers in a multi-center, blinded, parallel group randomized clinical trial of infants born at less than 29 weeks' gestation conducted from June 2012 and September 2015, excluding those with additional fatty acid supplementation or major congenital or chromosomal abnormalities. Follow-up took place from August 2018 to May 2021. Parents of surviving children who had not withdrawn from the original trial were invited to complete questionnaires when the child turned 5 years' corrected age. Infants were randomized to receive daily enteral emulsions providing 60 mg/kg/d of DHA or a soy-oil emulsion (with no DHA) from within the first 3 days of enteral feeding until 36 weeks' postmenstrual age or discharge home, whichever occurred first. The primary outcome of this follow-up was parent-rated behavior and emotional functioning as indicated by the Total Difficulties score of the Strengths and Difficulties Questionnaire. Parents also completed questionnaires about their child's behavioral manifestations of executive functioning, as well as a range of health outcomes to assess potential longer-term side effects of DHA intervention. Primary outcome data were available for 731 children (76% of 958 surviving eligible children; 361 in the intervention group and 370 in the control group). Of these 731, 452 (47%) were female, and the mean (SD) corrected age at follow-up was 5.4 (0.5) years. Following imputation for missing data, the mean Total Difficulties score was the same in both groups (intervention group, n = 465; mean [SD], 11.8 [6.3]; control group, n = 493; mean [SD], 11.8 [6.0]; mean difference adjusted for sex, gestational age stratum, and hospital, 0.01; 95% CI, -0.87 to 0.89; P = .98). There was no evidence for differences between the groups in any secondary outcomes of behavior, executive functioning, or health. In this follow-up of a randomized clinical trial, enteral DHA supplementation at the equivalent of the estimated in utero dose for infants born at less than 29 weeks' gestation did not improve behavioral functioning at age 5 years. There were no indications of adverse effects with DHA supplementation. Australian New Zealand Clinical Trial Registry: ACTRN12612000503820.

Development of neonatal-specific sequences for portable ultralow field magnetic resonance brain imaging: a prospective, single-centre, cohort study

Magnetic Resonance (MR) imaging is key for investigation of suspected newborn brain abnormalities. Access is limited in low-resource settings and challenging in infants needing intensive care. Portable ultralow field (ULF) MRI is showing promise in bedside adult brain imaging. Use in infants and children has been limited as brain-tissue composition differences necessitate sequence modification. The aim of this study was to develop neonatal-specific ULF structural sequences and test these across a range of gestational maturities and pathologies to inform future validation studies. Prospective cohort study within a UK neonatal specialist referral centre. Infants undergoing 3T MRI were recruited for paired ULF (64mT) portable MRI by convenience sampling from the neonatal unit and post-natal ward. Key inclusion criteria: 1) Infants with risk or suspicion of brain abnormality, or 2) preterm and term infants without suspicion of major genetic, chromosomal or neurological abnormality. Exclusions: presence of contra-indication for MR scanning. ULF sequence parameters were optimised for neonatal brain-tissues by iterative and explorative design. Neuroanatomic and pathologic features were compared by unblinded review, informing optimisation of subsequent sequence generations in a step-wise manner. Main outcome: visual identification of healthy and abnormal brain tissues/structures. ULF MR spectroscopy, diffusion, susceptibility weighted imaging, arteriography, and venography require pre-clinical technical development and have not been tested. Between September 23, 2021 and October 25, 2022, 102 paired scans were acquired in 87 infants; 1.17 paired scans per infant. Median age 9 days, median postmenstrual age 40+2 weeks (range: 31+3-53+4). Infants had a range of intensive care requirements. No adverse events observed. Optimised ULF sequences can visualise key neuroanatomy and brain abnormalities. In finalised neonatal sequences: T2w imaging distinguished grey and white matter (7/7 infants), ventricles (7/7), pituitary tissue (5/7), corpus callosum (7/7) and optic nerves (7/7). Signal congruence was seen within the posterior limb of the internal capsule in 10/11 infants on finalised T1w scans. In addition, brain abnormalities visualised on ULF optimised sequences have similar MR signal patterns to 3T imaging, including injury secondary to infarction (6/6 infants on T2w scans), hypoxia-ischaemia (abnormal signal in basal ganglia, thalami and white matter 2/2 infants on T2w scans, cortical highlighting 1/1 infant on T1w scan), and congenital malformations: polymicrogyria 3/3, absent corpus callosum 2/2, and vermian hypoplasia 3/3 infants on T2w scans. Sequences are susceptible to motion corruption, noise, and ULF artefact. Non-identified pathologies were small or subtle. On unblinded review, optimised portable MR can provide sufficient contrast, signal, and resolution for neuroanatomical identification and detection of a range of clinically important abnormalities. Blinded validation studies are now warranted. The Bill and Melinda Gates Foundation, the MRC, the Wellcome/EPSRC Centre for Medical Engineering, the MRC Centre for Neurodevelopmental Disorders, and the National Institute for Health Research (NIHR) Biomedical Research Centres based at Guy's and St Thomas' and South London & Maudsley NHS Foundation Trusts and King's College London.

The prevalence of congenital anomalies: nationwide study in 2020 in Estonia

Objective To assess the prevalence of congenital anomalies (CAs), chromosomal abnormalities and monogenic diseases among births and terminated pregnancies due to fetal anomalies (TOPFA) in 2020 in Estonia. Up to 2020 no data on prevalence of CAs in Estonia is reported. Methods For retrospective observational study data of all births and terminations of pregnancies after 12th gestational week from (i) the Estonian Medical Birth Registry, (ii) Abortion Registy, (iii) Health Insurance Fund and (iv) hospital records were linked. To calculate the total, live birth, stillbirth and TOPFA prevalence of CAs with 95% confidence intervals (CI), guidelines issued by EUROCAT, European network for the epidemiological surveillance of CAs, https://eu-rd-platform.jrc.ec.europa.eu/eurocat_en were followed. Results In 2020 the total prevalence of CAs, chromosomal abnormalities and monogenic diseases in Estonia was 378.6 per 10,000 births (95% CI 346.0, 413.5). The most prevalent CAs were heart defects, 163.7 cases per 10,000 births (95%CI 142.5, 187.2). The prevalence of chromosomal abnormalities and genetic diseases was 92.6 per 10,000 births (95%CI 76.8, 110.6), 80% of cases were among TOPFAs. No newborns with major aneuploidies (Trisomy 21, 18, 13, polyploidy) were reported in 2020. Live birth prevalence of CAs, including chromosomal abnormalities and genetic diseases was 258.4 per 10,000 live births (95%CI 231.5, 287.5) and stillbirth prevalence of CAs 0.8 per 10,000 births. Conclusions The prevalence of CAs and genetic disorders in Estonia is one of the highest compared to prevalence reported by other European regions. It indicates to high population coverage with prenatal diagnostics in Estonia. Low number of major aneuploidies among live births may reflect good detection rate of major chromosomal abnormalities and cultural preferences.

Intra-abdominal umbilical venous diameter and abdominal circumference discordance at 15-20weeks' gestation: simple markers in transverse abdominal plane to predict adverse pregnancy outcomes in monochorionic diamniotic twins.

This study aimed to investigate the association between simple markers in fetal abdominal plane, intra-abdominal umbilical venous diameter (DIUV) and abdominal circumference (AC) discordance at 15-20weeks' gestation, and adverse pregnancy outcomes in monochorionic diamniotic (MCDA) twins. We performed a retrospective analysis of MCDA twins with two live fetuses examined at 15-20weeks from Jun 2020 to Dec 2021 at Beijing Obstetrics and Gynecology Hospital. Measurement of fetal AC and DIUV was performed according to standard protocols. Twin pregnancies with major fetal structural anomalies, chromosomal abnormalities, miscarriage, and twin reversed arterial perfusion sequence were excluded. DIUV and AC discordance in MCDA twins with an adverse pregnancy outcome was compared with a normal pregnancy outcome. Furthermore, the performance of DIUV and AC discordance in predicting adverse pregnancy outcomes in MCDA twins was assessed. A total of 105 women with MCDA twin pregnancies were enrolled, contributing 179 visits. Adverse pregnancy outcomes occurred in 33.3% (35/105) of cases in our study. The intra-observer and inter-observer intraclass correlation coefficient (ICC) of both AC and DIUV were very good or excellent. There was no statistical difference in AC and DIUV discordance (%) between 15-16, 17-18, and 19-20weeks (χ2 = 3.928, P = 0.140; χ2 = 2.840, P = 0.242). Both AC and DIUV discordance were greater in twins with adverse pregnancy outcomes than that in twins with normal pregnancy outcome at each pregnancy periods. Both AC discordance (OR 1.2, 95% CI 1.1-1.3) and DIUV discordance (OR 1.2, 95% CI 1.1-1.2) were associated with adverse pregnancy outcomes. The AUC for predicting adverse pregnancy outcomes by AC discordance was 0.75 (95% CI 0.68-0.83), with a sensitivity of 58.7% (95% CI 51.9-64.5) and a specificity of 86.2% (95% CI 81.7-88.4). The AUC for predicting adverse pregnancy outcomes by DIUV was 0.78 (95% CI 0.70-0.86), with sensitivity and specificity of 65.1% (95% CI 58.1-70.3) and 86.2% (95% CI 81.7-88.4), respectively. The AC discordance and DIUV discordance could predict adverse pregnancy outcomes in MCDA twins. When these simple markers occurred, intensive surveillance was recommended.

Comparative Study of Perinatal Outcome in Uncomplicated Monochorionic Diamniotic versus Dichorionic Diamniotic Twins at a Specialized Twin Clinic—A Prospective Study

Abstract Background Monochorionic twins have higher perinatal morbidity and mortality than dichorionic twins. However, there is conflicting data on outcomes of uncomplicated monochorionic twins. Purpose of the Study The aim of this study is to compare the outcomes of apparently uncomplicated monochorionic twins to dichorionic twins. Methods This is a prospective study conducted from August 2019 to December 2020 at a specialized twin clinic. All twins, whose chorionicity was determined before 14 weeks with two live fetuses at 24 weeks, were recruited. Complicated monochorionic diamniotic (MCDA) twins with twin-to-twin transfusion syndrome, twin anemia polycythemia syndrome, selective fetal growth restriction before 24 weeks and single or double fetal demise before 24 weeks were excluded. Other exclusion criteria were major congenital and chromosomal abnormalities, higher order multiples, monoamniotic twins, and twins with undetermined chorionicity antenatally. Both the groups were followed till delivery and neonates followed till 28 days. Maternal and neonatal outcomes were studied and compared. Results One-hundred forty-eight mothers with dichorionic diamniotic (DCDA) and 74 with uncomplicated MCDA were studied. Mean gestational age at delivery was 35 weeks in both the groups. Maternal, fetal, and neonatal morbidities were similar in both, except early onset preeclampsia that was higher in the DCDA group. Prospective risk of stillbirth for DCDA and MCDA after 24 weeks was 1.35 and 4.05%, respectively. Prospective risk of stillbirth for DCDA and MCDA after 30 weeks was 1.49 and 0%, respectively. Conclusion The maternal and perinatal outcomes in uncomplicated MCDA twins are similar to DCDA twins. Prospective risk of stillbirth after 30 weeks is extremely low. Hence, uncomplicated MCDA twins should not be delivered electively before 36 weeks.

Cytogenetics evaluation of 261 couples with first-trimester recurrent pregnancy loss: A prevalent case–control study

Introduction: Recurrent pregnancy loss (RPL) is a common occurrence which affects approximately 15-20% of couples. Chromosomal abnormality is an important cause of recurrent abortions especially if either of the partner is a carrier of balanced translocation. The current study aimed to determine the prevalence of chromosomal abnormalities in couples suffering from first trimester RPL and compare with normal control. Materials and Methods: A prospective case-control study, in which 261 couples with history of two or more abortions were evaluated for various chromosomal abnormalities; and compared with 190 healthy couples with no history of abortion and at least one normal biological child. Peripheral blood T-lymphocytes were cultured using RPMI-1640 medium for obtaining metaphases and chromosomal analysis. SPSS software and Student's t test were used. p value < 0.05 was considered statistically significant. Results: Among 261 couples in RPL group, 240(91.95%) had normal karyotype, 17(6.51%) had major chromosomal abnormalities and 04(1.53%) had polymorphic variants. Most of the couples had two abortions (39.8%). Females were more commonly affected with M:F=0.214. Structural abnormalities (n=12,70.59%) were more frequent than numerical abnormalities (n=5,29.41%). There was no statistical correlation between age, number of abortions and major chromosomal abnormalities (p=0.06). Conclusion: Chromosomal aberrations in carrier parents, predispose them to RPL and can also be transmitted to the offspring which may results in imbalance in their genetic constitution, thus justifying the requirement of cytogenetic testing in these patients.

Isolated aortic arch anomalies are associated with defect severity and outcome in patients with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) patients often have suspected isolated aortic arch anomalies (IAAA) on imaging. The purpose of this work was to describe the incidence and outcomes of CDH + IAAA patients. Cardiovascular data were collected for infants from the CDH Study Group born between 2007 and 2019. IAAA were defined as coarctation of aorta, hypoplastic aortic arch, interrupted aortic arch, and aortic aneurysmal disease on early, postnatal echocardiography. Patients with major cardiac malformations and/or chromosomal abnormalities were excluded. Primary outcomes included the rate of aortic intervention, rates of extracorporeal life support (ECLS) utilization, and mortality. Of 6357 CDH infants, 432 (7%) were diagnosed with a thoracic aortic anomaly. Of these, 165 were diagnosed with IAAA, most commonly coarctation of the aorta (n = 106; 64%) or hypoplastic aortic arch (n = 58; 35%). CDH + IAAA patients had lower birthweights (3kg vs. 2.9kg) and Apgar scores (7 vs. 6) than patients without IAAA (both χ2 p < 0.001). CDH + IAAA were less likely to undergo diaphragm repair (72 vs. 87%, p < 0.001), and overall mortality was higher for CDH + IAAA infants (58 vs. 24%, p < 0.001). When controlling for defect size, birth weight, and Apgar, IAAA were significantly associated with mortality (OR 3.3, 95% CI 2.2-5.0; p < 0.01) but not associated with ECLS (OR 0.98, 95% CI 0.65-1.50; p = 0.90). Only17% (n = 28) of CDH + IAAA patients underwent aortic intervention. IAAA in CDH are associated with increased mortality. This often simply reflects severity of the defect and thoracic anatomic derangement, as opposed to unique aortic pathology, givenfew CDH + IAAA patients undergo aortic intervention.

Fishing for ETV6/RUNX1 fusion and MLL gene rearrangements and their additional abnormalities in childhood acute lymphoblastic leukemia patients of Kashmir

ObjectiveEvidence suggests that ETV6/RUNX1 translocation in pediatric acute lymphocytic leukemia shows geographical variation. Therefore, the present study aimed at unveiling the incidence of ETV6/RUNX1 fusion in pediatric acute lymphocytic leukemia cases of this region using fluorescent in-situ hybridization. Besides, we aimed to determine the incidence of MLL gene rearrangement and the pattern of chromosomal abnormalities in this study group. MethodsSamples from 57 acute lymphocytic leukemia cases of pediatric age group were subjected to fluorescent in-situ hybridization and conventional cytogenetic analysis using standard methods. ResultsConventional cytogenetic analysis revealed chromosomal abnormalities in 19.3% cases. The other major chromosomal abnormalities reported were monosomies in 10.5%, hypodiploidy in 7%, marker chromosomes in 3.5% and deletions in 3.5% cases. We found a 44,XX,-7,-18, r(5), i(17q) complex karyotype in one of the cases. Fluorescent in-situ hybridization analysis revealed ETV6/RUNX1 translocation to be present in 28.07% cases and MLL gene rearrangement in 3.5% cases. 12.5% of ETV6/RUNX1 fusion positive cases were found to have a loss of ETV6 allele. Besides, 8.8% cases were found to exhibit a signal pattern suggestive of RUNX1 amplification. ETV6 gene deletion and MLL gene amplification was detected in 3.5% cases each, of our study. ConclusionsFrequency of ETV6/RUNX1 fusion oncogene was found to be higher in pediatric ALL cases of Kashmir region as compared to that reported from other parts of India. Besides, a case was found to have a karyotype viz 44,XX,-7,-18, r(5), i(17q) that has not been reported elsewhere in the childhood ALL.

Major Chromosomal Abnormalities and Necrotizing Enterocolitis: Is there a Link?

Major Chromosomal Abnormalities and Necrotizing Enterocolitis: Is there a Link?

Is cell-free fetal DNA testing a safe option for women in a high-risk population after combined first-trimester testing?

ObjectivesOur study aimed to examine the relevance of cell-free fetal DNA (cfDNA) testing on the screening of chromosomal defects and the issue of pregnancies in patients with a risk over 1:50 after the first-trimester combined test. MethodsThis is a retrospective monocentric study. We included all consecutive patients with a singleton pregnancy between January 2015 and December 2020 attending our fetal medicine center because the estimated risk for trisomy 21 after the first-trimester combined screening was over 1:50. The patients could either choose to have invasive testing or cell-free DNA testing. We collected data about the patient, the tests results (cfDNA, karyotype) and the pregnancy outcome (born alive, medical termination, miscarriage or intrauterine fetal death). ResultsWe included 98 patients with an estimated risk for trisomy 21 over 1:50. We found a total of 14 major chromosomal abnormalities (14/98; 14.3%), of which: thirteen trisomies 21 and one triploidy 69, XXY. A cfDNA testing was chosen by 34 (34/98; 34.7%) patients. Among the pathological results of invasive testing, 5 (5/64; 7.8%) couldn't be targeted by cfDNA testing. Two of them were placental mosaicism, one a triploidy 69, XXY, and two defects inherited from a parent and considered benign. There was no miscarriage linked to an invasive test in the population study. ConclusionIn our monocentric cohort, a third of the patients choose cfDNA in a case of a risk over 1:50 after combined testing. Even if this cohort is too small to draw definitive conclusions, cfDNA could be safe in a high-risk population after combined testing. None of the chromosomal abnormalities found at the karyotype and non-detectable by cfDNA was a loss of information that impacted pregnancy follow-up. Further study could explore the input of Genome-Wide cfDNA and chromosomal micro-array in this population.

Correlation of Maternal Age and Chromosomal Abnormality in Products of Conception- A Single Centric Study

Purpose: The purpose of this study is to find out the types and incidence rate of chromosomal abnormalities and the relationship between maternal age and chromosomal abnormality in products of conception by retrospective analysis. Method: Karyotype study using standard GTG banding and FISH study for aneuploidy detection was done from products of conception samples. Results: A total of 513 cases of products of conception were studied retrospectively. 98 cases were studied by conventional cytogenetic technique and 415 cases were studied by a FISH method. The chromosomal abnormality was observed in 97 cases (18.91%). Trisomy was found to be a major chromosomal abnormality amongst the cases studied, followed by triploidy and monosomy. A higher incidence of chromosomal abnormality was found in women with advanced maternal age as compared to the maternal age less than 35 years.

Basis of Inheritance in Humans.

In humans, traits and diseases are inherited primarily by complex or multifactorial modes. These imply that contributions come from more than one gene, and these can be influenced by the environment. They are the mechanisms that underlie inheritance of dental caries, erosive tooth wear, and amelogenesis. Major gene effects (monogenic or Mendelian inheritance) and chromosomal abnormalities explain the scenarios that do not fit well with complex or multifactorial inheritance. Furthermore, there are numerous non-traditional modes of inheritance. These are all exceptions of the most common complex modes of inheritance, and their understanding is important for a number of relatively rare scenarios in humans. In this chapter, these modes of inheritance are presented, and some rare conditions are explored to highlight the relevance of studying rare diseases for the understanding of more common diseases that affect populations, using dental caries as a model.

Gene utility recapitulates chromosomal aberrancies in advanced stage neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid tumor in children. Although only a few recurrent somatic mutations have been identified, chromosomal abnormalities, including the loss of heterozygosity (LOH) at the chromosome 1p and gains of chromosome 17q, are often seen in the high-risk cases. The biological basis and evolutionary forces that drive such genetic abnormalities remain enigmatic. Here, we conceptualize the Gene Utility Model (GUM) that seeks to identify genes driving biological signaling via their collective gene utilities and apply it to understand the impact of those differentially utilized genes on constraining the evolution of NB karyotypes. By employing a computational process-guided flow algorithm to model gene utility in protein–protein networks that built based on transcriptomic data, we conducted several pairwise comparative analyses to uncover genes with differential utilities in stage 4 NBs with distinct classification. We then constructed a utility karyotype by mapping these differentially utilized genes to their respective chromosomal loci. Intriguingly, hotspots of the utility karyotype, to certain extent, can consistently recapitulate the major chromosomal abnormalities of NBs and also provides clues to yet identified predisposition sites. Hence, our study not only provides a new look, from a gene utility perspective, into the known chromosomal abnormalities detected by integrative genomic sequencing efforts, but also offers new insights into the etiology of NB and provides a framework to facilitate the identification of novel therapeutic targets for this devastating childhood cancer.

Reexamining the optimal nuchal translucency cutoff for diagnostic testing in the cell-free DNA and microarray era: results from the Victorian Perinatal Record Linkage study

The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine recently recommended offering genetic counseling and diagnostic testing for enlarged nuchal translucency at ≥3.0 mm, regardless of previous negative screening with noninvasive prenatal testing. This study aimed to perform a population-based, individual record linkage study to determine the optimal definition of an enlarged nuchal translucency for the detection of atypical chromosome abnormalities. This was a retrospective study of women resident in Victoria, Australia, undergoing combined first-trimester screening during the 24-month period from January 2015 to December 2016. Linkages between statewide results for combined first-trimester screening, prenatal diagnostic procedures, and postnatal cytogenetic results from products of conception and infants up to 12 months of age were used to ascertain the frequency and type of chromosome abnormality by gestation and nuchal translucency measurement. An atypical chromosome abnormality was defined as any major chromosome abnormality other than whole chromosome aneuploidy involving chromosomes 21, 18, 13, X, and Y. Of the 81,244 singleton pregnancies undergoing combined first-trimester screening, 491 (0.60%) had a nuchal translucency of ≥3.5 mm, 534 (0.66%) had a nuchal translucency of 3.0 to 3.4 mm, and 80,219 (98.74%) had a nuchal translucency of < 3.0 mm. When grouped by nuchal translucency multiples of the median (MoM), 192 (0.24%) had a nuchal translucency of ≥3.0 MoM, 513 (0.63%) had a nuchal translucency of 1.9 to 2.9 MoM, and 80,539 (99.13%) had a nuchal translucency of <1.9 MoM. A total of 1779 pregnancies underwent prenatal or postnatal diagnostic testing, of which 89.60% were performed by whole-genome single-nucleotide polymorphism chromosomal microarray. The frequency of total major chromosome abnormalities was significantly higher in the group with a nuchal translucency of ≥3.5 mm (147 of 491, 29.94%) than the group with a nuchal translucency of 3.0 to 3.4 mm (21 of 534, 3.93%) or a nuchal translucency of <3.0 mm (71 of 80,219, 0.09%) (P<.001). There were 93 atypical chromosome abnormalities in the total screened cohort. The frequency of an atypical chromosome abnormality was 4.07% (95% confidence interval, 2.51-6.22), 0.37% (95% confidence interval, 0.05-1.35), and 0.09% (95% confidence interval, 0.07-0.11) in the groups with a nuchal translucency of ≥3.5 mm, 3.0 to 3.4 mm, and <3.0 mm, respectively. The frequency of atypical chromosome abnormalities was 4.69% (95% confidence interval, 2.17-8.71), 2.53% (95% confidence interval, 1.36-4.29), and 0.09% (95% confidence interval, 0.07-0.11) in the groups with a nuchal translucency of ≥3.0 MoM, 1.9 to 2.9 MoM, and <1.9 MoM, respectively. When defining thresholds for offering diagnosis with chromosomal microarray at 11 to 13 weeks, both a nuchal translucency threshold of 1.9 MoM and a fixed threshold of 3.0 mm captured 22 of 93 fetuses (23.7%) with an atypical chromosome abnormality. Of these, 50.0% had a coexisting fetal abnormality on ultrasound. However, the gestation-specific threshold of 1.9 MoM had a better specificity than 3.0 mm. The positive predictive value of an enlarged nuchal translucency for any atypical chromosome abnormality was 1 in 47 for nuchal translucency of >3.0 mm and 1 in 32 for nuchal translucency of >1.9 MoM. Our nuchal translucency threshold of 1.9 MoM captured 0.87% of fetuses, thus approximating the 99th centile. A gestational age-adjusted nuchal translucency threshold of 1.9 MoM or 99th centile is superior to the fixed cutoff of 3.0 mm for the identification of atypical chromosome abnormalities. The risk of an atypical chromosome abnormality in a fetus with an enlarged nuchal translucency is more than tripled in the presence of an additional ultrasound abnormality.

First-trimester fetal heart evaluation: time to move forward.

First-trimester fetal heart evaluation: time to move forward.

The Spectrum of Chromosomal Abnormalities and Endocrine Profile of Male Infertility with Nonobstructive Semen Abnormality: A Case-Control Study.

Background:Primary infertility is a common occurrence which affects approximately 15% of couples who desire to begin their family. Chromosomal abnormalities are well-established causes of pregnancy loss but may also have a role in explaining the cause of male infertility, especially with nonobstructive semen abnormalities. Hence, awareness regarding safety of artificial reproductive technology in these individuals due to underlying sperm aneuploidy is required.Aims:The aims of the study are to determine the prevalence of chromosomal abnormalities in primary infertile males with nonobstructive semen abnormalities and correlate with their endocrine profile.Study Design:A case–control study, in which 100 males with primary infertility and non-obstructive semen abnormalities were evaluated for chromosomal abnormality and hormonal profile; and were compared with 50 healthy males with normal semen analysis and at least one biological child.Materials and Methods:Blood T-lymphocytes were cultured using RPMI-1640 medium for obtaining metaphases and chromosomal analysis.Statistical Analysis:SPSS software and Student's t-test were used. A p < 0.05 was considered statistically significant.Results:Azoospermia (81%) was the most common nonobstructive semen abnormality. Overall prevalence of major chromosomal abnormalities and polymorphic variants was 16% and 7%, respectively. Klinefelter syndrome was the most common sex chromosomal numerical abnormality seen in 6.17% of cases with azoospermia. All healthy control males had 46, XY karyotype. Higher levels of follicle-stimulating hormone and luteinizing hormone and lower levels of testosterone along with testicular volumes were observed in infertile males with abnormal karyotype (p < 0.05).Conclusion:Primary infertile males with nonobstructive semen abnormality have high frequency of chromosomal aberrations, which justify the requirement of cytogenetic testing in these patients.

Accuracy of Ultrasound to Predict Neonatal Birth Weight Among Fetuses With Gastroschisis: Impact on Timing of Delivery.

To determine the accuracy of ultrasound estimation of fetal weight among fetuses with gastroschisis and how the diagnosis of fetal growth restriction (FGR) affects the timing of delivery. This was a retrospective cohort study including all fetuses with a diagnosis of gastroschisis at our institution from November 2012 through October 2017. We excluded multiple gestations, pregnancies with major structural or chromosomal abnormalities, and those for which prenatal and postnatal follow-up were unavailable. Performance characteristics of ultrasound to predict being small for gestational age (SGA) were calculated for the first and last ultrasound estimations of fetal weight. Our cohort included 75 cases of gastroschisis. At the initial ultrasound estimation, 15 of 58 (25.9%) fetuses met criteria for FGR; 48 of 70 (68.6%) met criteria at the time of the last ultrasound estimation (median, 34.7 weeks). Cesarean delivery was performed for 37 of 75 (49.3%), with FGR and concern for fetal distress as the indication for delivery in 17 of 37 (45.9%). Only 6 of 17 (35.3%) of the neonates born by cesarean delivery for an indication of FGR and fetal distress were SGA. The initial ultrasound designation of FGR corresponded to SGA at birth in 8 of 15 (53.3%), whereas the last ultrasound estimation corresponded to SGA in 17 of 48 (35.4%). The initial ultrasound estimation agreed with the last ultrasound estimation before delivery with the diagnosis of FGR in 13 of 15 (86.7%). Ultrasound in the third trimester was sensitive but had a low positive predictive value and low accuracy for the diagnosis of SGA at birth for fetuses with gastroschisis. A large proportion of fetuses were born by cesarean delivery with indications related to FGR or fetal concerns.

VP11.07: Fetal urinary tract obstruction with normal amniotic fluid and outcomes

To investigate the causes and outcomes in pregnancies where a lower urinary tract obstruction with normal levels of AF was diagnosed in the second trimester. We studied all pregnancies with a sonographic diagnosis of lower urinary tract obstruction and normal AFI between 2015 and 2019. Fetuses with major structural and/or chromosomal abnormalities were excluded from the study. We defined urinary tract obstruction as the presence of an enlarged urinary bladder with bilateral hydroureters and hydronephrosis and normal AF as an AFI bigger than 9cm between 20 and 24 weeks. Cases that developed significant oligohydramnios were examined for eligibility for intervention. Data regarding demographics, fetal interventions, postnatal diagnoses and care (need for respiratory support or dialysis, overall survival) were collected. Of the 21 cases, 7 fetuses maintained a normal AFI throughout the pregnancy (33%) while 12 went on to develop oligohydramnios. In 8 cases oligohydramnios manifested between 28 and 35 weeks (7 fetuses underwent intervention), whille 4 developed oligohydramnios after 35 weeks and required no intervention. There was only one case of neonatal death (severe oligohydramnios at 27 weeks – patient declined fetal intervention). Perinatal survival of neonates diagnosed with urinary tract obstruction and normal AFI is good, however, they are at greater risk for end-stage renal disease and need of dialysis.