A novel unbalanced translocation between chromosomes 5p and 18q leading to dysmorphology and global developmental delay.

BACKGROUND: Individuals with various sized terminal duplications of chromosome 5p or terminal deletions of chromosome 18q have been described. These aberrations may cause congenital malformations and intellectual disability of varying severity. METHODS: Via an international collaborative effort, we obtained a cytogenetic diagnosis for a 5-year-old boy of Afro-Caribbean ancestry who has global developmental delay, dysmorphology, hypotonia, feeding difficulties, bilateral club feet, and intellectual disability. RESULTS: Conventional G-banded karyotyping showed additional chromatin of unknown origin on the long arm of chromosome 18. SNP microarray confirmed the loss of ~6.4 Mb from chromosome 18q: arr[hg19] 18q22.3-q23(71,518,518-77,943,115)x1. The source of the additional chromatin was determined from the microarray to be ~32 Mb from the short arm of chromosome 5 (arr[hg19] 5p13.3-p15.33(51,045-32,062,984)x3). The unbalanced translocation was verified by fluorescent in situ hybridization (FISH). Both parents are healthy and have normal karyotypes suggesting that this abnormality arose de novo in the proband, although gonadal mosaicism in a parent cannot be excluded. CONCLUSION: The combination of clinical features in this individual is most likely due to the partial deletion of 18q and partial duplication of 5p, which to our knowledge has not been previously described.

Frequency of Sex Chromosome Involvement in a Large Cohort of Subjects with Two Copy Number Variants.

Copy number variants (CNVs) are a common finding in the clinical setting and contribute to both genetic variation and disease. Studies have described the accumulation of multiple CNVs as a disease-modifying mechanism. While it has been described how additional CNVs may play a role in phenotype, in which ways and to what extent sex chromosomes are involved in dual CNV scenario has not been fully defined. To describe the distribution of CNVs, a secondary data analysis using the DECIPHER database on 2,273 de-identified individuals with two CNVs was performed. CNVs were designated larger and secondary based on size and characteristics. We found that the X chromosome was observed to be the most common chromosome involved in secondary CNVs. Further analysis showed CNVs on the sex chromosome have significant differences compared to autosomes when comparing median size (p = 0.013), pathogenicity groups (p < 0.001), and variant classification (p = 0.001). Lastly, we identified chromosome combinations for larger and secondary CNVs and observed the plurality of secondary CNVs fell in the same chromosome as the larger. The observations of this study provide additional information on sex chromosome CNV involvement in a variety of indications.

Experiences with offering pro bono medical genetics services in the West Indies: Benefits to patients, physicians, and the community.

We describe our experiences with organizing pro bono medical genetics and neurology outreach programs on several different resource-limited islands in the West Indies. Due to geographic isolation, small population sizes, and socioeconomic disparities, most Caribbean islands lack medical services for managing, diagnosing, and counseling individuals with genetic disorders. From 2015 to 2019, we organized 2-3 clinics per year on various islands in the Caribbean. We also organized a week-long clinic to provide evaluations for children suspected of having autism spectrum disorder. Consultations for over 100 different individuals with suspected genetic disorders were performed in clinics or during home visits following referral by locally registered physicians. When possible, follow-up visits were attempted. When available and appropriate, clinical samples were shipped to collaborating laboratories for molecular analysis. Laboratory tests included karyotyping, cytogenomic microarray analysis, exome sequencing, triplet repeat expansion testing, blood amino acid level determination, biochemical assaying, and metabolomic profiling. We believe that significant contributions to healthcare by genetics professionals can be made even if availability is limited. Visiting geneticists may help by providing continuing medical education seminars. Clinical teaching rounds help to inform local physicians regarding the management of genetic disorders with the aim of generating awareness of genetic conditions. Even when only periodically available, a visiting geneticist may benefit affected individuals, their families, their local physicians, and the community at large.

Application of exome sequencing to diagnose a novel presentation of the Cornelia de Lange syndrome in an Afro-Caribbean family.

BACKGROUND: Cornelia de Lange syndrome (CdLS) comprises a recognizable pattern of multiple congenital anomalies caused by variants of the DNA cohesion complex. Affected individuals may display a wide range of phenotypic severity, even within the same family. METHODS: Exome sequencing and confirmatory Sanger sequencing showed the same previously described p.Arg629Ter NIPBL variant in two half-brothers affected with CdLS. Clinical evaluations were obtained in a pro bono genetics clinic. RESULTS: One brother had relatively mild proportionate limb shortening; the other had complete bilateral hypogenesis of the upper arm with absence of lower arm structures, terminal transverse defects, and no digit remnants. His complex lower limb presentation included long bone deficiency and a deviated left foot. The mother had intellectual disability and microcephaly but lacked facial features diagnostic of the CdLS. CONCLUSION: We describe a collaboration between a pediatrics team from a resource-limited nation and USA-based medical geneticists. Reports describing individuals of West Indian ancestry are rarely found in the medical literature. Here, we present a family of Afro-Caribbean ancestry with CdLS presenting with phenotypic variability, including unusual lower limb abnormalities. The observation of this novel family adds to our knowledge of the phenotypic and molecular aspects of CdLS.

Parental somatic mosaicism for CNV deletions - A need for more sensitive and precise detection methods in clinical diagnostics settings.

To further assess the scale and level of parental somatic mosaicism, we queried the CMA database at Baylor Genetics. We selected 50 unrelated families where clinically relevant apparent de novo CNV-deletions were found in the affected probands. Parental blood samples screening using deletion junction-specific PCR revealed four parents with somatic mosaicism. Droplet digital PCR (ddPCR), qPCR, and amplicon-based next-generation sequencing (NGS) were applied to validate these findings. Using ddPCR levels of mosaicism ranged from undetectable to 18.5%. Amplicon-based NGS and qPCR for the father with undetectable mosaicism was able to detect mosaicism at 0.39%. In one mother, ddPCR analysis revealed 15.6%, 10.6%, 8.2%, and undetectable levels of mosaicism in her blood, buccal cells, saliva, and urine samples, respectively. Our data suggest that more sensitive and precise methods, e.g. CNV junction-specific LR-PCR, ddPCR, or qPCR may allow for a more refined assessment of the potential disease recurrence risk for an identified variant.

Copy number variant and runs of homozygosity detection by microarrays enabled more precise molecular diagnoses in 11,020 clinical exome cases.

BACKGROUND: Exome sequencing (ES) has been successfully applied in clinical detection of single nucleotide variants (SNVs) and small indels. However, identification of copy number variants (CNVs) using ES data remains challenging. The purpose of this study is to understand the contribution of CNVs and copy neutral runs of homozygosity (ROH) in molecular diagnosis of patients referred for ES. METHODS: In a cohort of 11,020 consecutive ES patients, an Illumina SNP array analysis interrogating mostly coding SNPs was performed as a quality control (QC) measurement and for CNV/ROH detection. Among these patients, clinical chromosomal microarray analysis (CMA) was performed at Baylor Genetics (BG) on 3229 patients, either before, concurrently, or after ES. We retrospectively analyzed the findings from CMA and the QC array. RESULTS: The QC array can detect ~ 70% of pathogenic/likely pathogenic CNVs (PCNVs) detectable by CMA. Out of the 11,020 ES cases, the QC array identified PCNVs in 327 patients and uniparental disomy (UPD) disorder-related ROH in 10 patients. The overall PCNV/UPD detection rate was 5.9% in the 3229 ES patients who also had CMA at BG; PCNV/UPD detection rate was higher in concurrent ES and CMA than in ES with prior CMA (7.2% vs 4.6%). The PCNVs/UPD contributed to the molecular diagnoses in 17.4% (189/1089) of molecularly diagnosed ES cases with CMA and were estimated to contribute in 10.6% of all molecularly diagnosed ES cases. Dual diagnoses with both PCNVs and SNVs were detected in 38 patients. PCNVs affecting single recessive disorder genes in a compound heterozygous state with SNVs were detected in 4 patients, and homozygous deletions (mostly exonic deletions) were detected in 17 patients. A higher PCNV detection rate was observed for patients with syndromic phenotypes and/or cardiovascular abnormalities. CONCLUSIONS: Our clinical genomics study demonstrates that detection of PCNV/UPD through the QC array or CMA increases ES diagnostic rate, provides more precise molecular diagnosis for dominant as well as recessive traits, and enables more complete genetic diagnoses in patients with dual or multiple molecular diagnoses. Concurrent ES and CMA using an array with exonic coverage for disease genes enables most effective detection of both CNVs and SNVs and therefore is recommended especially in time-sensitive clinical situations.

Clinical exome sequencing reveals locus heterogeneity and phenotypic variability of cohesinopathies.

PURPOSE: Defects in the cohesin pathway are associated with cohesinopathies, notably Cornelia de Lange syndrome (CdLS). We aimed to delineate pathogenic variants in known and candidate cohesinopathy genes from a clinical exome perspective. METHODS: We retrospectively studied patients referred for clinical exome sequencing (CES, N = 10,698). Patients with causative variants in novel or recently described cohesinopathy genes were enrolled for phenotypic characterization. RESULTS: Pathogenic or likely pathogenic single-nucleotide and insertion/deletion variants (SNVs/indels) were identified in established disease genes including NIPBL (N = 5), SMC1A (N = 14), SMC3 (N = 4), RAD21 (N = 2), and HDAC8 (N = 8). The phenotypes in this genetically defined cohort skew towards the mild end of CdLS spectrum as compared with phenotype-driven cohorts. Candidate or recently reported cohesinopathy genes were supported by de novo SNVs/indels in STAG1 (N = 3), STAG2 (N = 5), PDS5A (N = 1), and WAPL (N = 1), and one inherited SNV in PDS5A. We also identified copy-number deletions affecting STAG1 (two de novo, one of unknown inheritance) and STAG2 (one of unknown inheritance). Patients with STAG1 and STAG2 variants presented with overlapping features yet without characteristic facial features of CdLS. CONCLUSION: CES effectively identified disease-causing alleles at the mild end of the cohensinopathy spectrum and enabled characterization of candidate disease genes.

Genetic diagnosis of Down syndrome in an underserved community.

It is a matter of course that in high-income countries, infants born with features suggestive of Down syndrome (DS) are offered genetic testing for confirmation of a clinical diagnosis. Benefits of a definitive diagnosis include an end to the diagnostic odyssey, informed prognosis, opportunities for caregiver support, inclusion to social support networks, and more meaningful genetic counseling. The healthcare experience for families of children born with DS in low- and middle-income nations is in stark contrast with such a level of care. Barriers to obtaining genetic diagnosis might include economic disparities, geographical isolation, and lack of access to health care professionals trained in genetic medicine. As part of a combined research and community outreach effort, we provided genetic testing for several patients with DS. These individuals and their families live on several resource-limited Caribbean islands and have either limited or virtually no access to medical genetics services. Within this group were three families with recurrent DS. Karyotype established that translocation events were not involved in the DS in any of these families. This information enabled genetic counseling to help family members understand their recurrent DS. A definitive diagnosis of DS is beneficial to families in resource-limited communities and may help to provide such families with genetic counseling, reassurance, and peace of mind.

Positive predictive value estimates for cell-free noninvasive prenatal screening from data of a large referral genetic diagnostic laboratory.

BACKGROUND: Since its debut in 2011, cell-free fetal DNA screening has undergone rapid expansion with respect to both utilization and coverage. However, conclusive data regarding the clinical validity and utility of this screening tool, both for the originally included common autosomal and sex-chromosomal aneuploidies as well as the more recently added chromosomal microdeletion syndromes, have lagged behind. Thus, there is a continued need to educate clinicians and patients about the current benefits and limitations of this screening tool to inform pre- and posttest counseling, pre/perinatal decision making, and medical risk assessment/management. OBJECTIVE: The objective of this study was to determine the positive predictive value and false-positive rates for different chromosomal abnormalities identified by cell-free fetal DNA screening using a large data set of diagnostic testing results on invasive samples submitted to the laboratory for confirmatory studies. STUDY DESIGN: We tested 712 patient samples sent to our laboratory to confirm a cell-free fetal DNA screening result, indicating high risk for a chromosome abnormality. We compiled data from all cases in which the indication for confirmatory testing was a positive cell-free fetal DNA screen, including the common trisomies, sex chromosomal aneuploidies, microdeletion syndromes, and other large genome-wide copy number abnormalities. Testing modalities included fluorescence in situ hybridization, G-banded karyotype, and/or chromosomal microarray analysis performed on chorionic villus samples, amniotic fluid, or postnatally obtained blood samples. Positive predictive values and false-positive rates were calculated from tabulated data. RESULTS: The positive predictive values for trisomy 13, 18, and 21 were consistent with previous reports at 45%, 76%, and 84%, respectively. For the microdeletion syndrome regions, positive predictive values ranged from 0% for detection of Cri-du-Chat syndrome and Prader-Willi/Angelman syndrome to 14% for 1p36 deletion syndrome and 21% for 22q11.2 deletion syndrome. Detection of sex chromosomal aneuploidies had positive predictive values of 26% for monosomy X, 50% for 47,XXX, and 86% for 47,XXY. CONCLUSION: The positive predictive values for detection of common autosomal and sex chromosomal aneuploidies by cell-free fetal DNA screening were comparable with other studies. Identification of microdeletions was associated with lower positive predictive values and higher false-positive rates, likely because of the low prevalence of the individual targeted microdeletion syndromes in the general population. Although the obtained positive predictive values compare favorably with those seen in traditional screening approaches for common aneuploidies, they highlight the importance of educating clinicians and patients on the limitations of cell-free fetal DNA screening tests. Improvement of the cell-free fetal DNA screening technology and continued monitoring of its performance after introduction into clinical practice will be important to fully establish its clinical utility. Nonetheless, our data provide valuable information that may aid result interpretation, patient counseling, and clinical decision making/management.

Identification of novel candidate disease genes from de novo exonic copy number variants.

BACKGROUND: Exon-targeted microarrays can detect small (<1000 bp) intragenic copy number variants (CNVs), including those that affect only a single exon. This genome-wide high-sensitivity approach increases the molecular diagnosis for conditions with known disease-associated genes, enables better genotype-phenotype correlations, and facilitates variant allele detection allowing novel disease gene discovery. METHODS: We retrospectively analyzed data from 63,127 patients referred for clinical chromosomal microarray analysis (CMA) at Baylor Genetics laboratories, including 46,755 individuals tested using exon-targeted arrays, from 2007 to 2017. Small CNVs harboring a single gene or two to five non-disease-associated genes were identified; the genes involved were evaluated for a potential disease association. RESULTS: In this clinical population, among rare CNVs involving any single gene reported in 7200 patients (11%), we identified 145 de novo autosomal CNVs (117 losses and 28 intragenic gains), 257 X-linked deletion CNVs in males, and 1049 inherited autosomal CNVs (878 losses and 171 intragenic gains); 111 known disease genes were potentially disrupted by de novo autosomal or X-linked (in males) single-gene CNVs. Ninety-one genes, either recently proposed as candidate disease genes or not yet associated with diseases, were disrupted by 147 single-gene CNVs, including 37 de novo deletions and ten de novo intragenic duplications on autosomes and 100 X-linked CNVs in males. Clinical features in individuals with de novo or X-linked CNVs encompassing at most five genes (224 bp to 1.6 Mb in size) were compared to those in individuals with larger-sized deletions (up to 5 Mb in size) in the internal CMA database or loss-of-function single nucleotide variants (SNVs) detected by clinical or research whole-exome sequencing (WES). This enabled the identification of recently published genes (BPTF, NONO, PSMD12, TANGO2, and TRIP12), novel candidate disease genes (ARGLU1 and STK3), and further confirmation of disease association for two recently proposed disease genes (MEIS2 and PTCHD1). Notably, exon-targeted CMA detected several pathogenic single-exon CNVs missed by clinical WES analyses. CONCLUSIONS: Together, these data document the efficacy of exon-targeted CMA for detection of genic and exonic CNVs, complementing and extending WES in clinical diagnostics, and the potential for discovery of novel disease genes by genome-wide assay.

Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features.

Bromodomain PHD finger transcription factor (BPTF) is the largest subunit of nucleosome remodeling factor (NURF), a member of the ISWI chromatin-remodeling complex. However, the clinical consequences of disruption of this complex remain largely uncharacterized. BPTF is required for anterior-posterior axis formation of the mouse embryo and was shown to promote posterior neuroectodermal fate by enhancing Smad2-activated wnt8 expression in zebrafish. Here, we report eight loss-of-function and two missense variants (eight de novo and two of unknown origin) in BPTF on 17q24.2. The BPTF variants were found in unrelated individuals aged between 2.1 and 13 years, who manifest variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10). Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of gene function, we observed a significant reduction in head size of F0 mutants compared to control larvae. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and phospho-histone H3 (PH3) staining to assess apoptosis and cell proliferation, respectively, showed a significant increase in cell death in F0 mutants compared to controls. Additionally, we observed a substantial increase of the ceratohyal angle of the craniofacial skeleton in bptf F0 mutants, indicating abnormal craniofacial patterning. Taken together, our data demonstrate the pathogenic role of BPTF haploinsufficiency in syndromic neurodevelopmental anomalies and extend the clinical spectrum of human disorders caused by ablation of chromatin remodeling complexes.

Characterization of chromosomal abnormalities in pregnancy losses reveals critical genes and loci for human early development.

Detailed characterization of chromosomal abnormalities, a common cause for congenital abnormalities and pregnancy loss, is critical for elucidating genes for human fetal development. Here, 2,186 product-of-conception samples were tested for copy-number variations (CNVs) at two clinical diagnostic centers using whole-genome sequencing and high-resolution chromosomal microarray analysis. We developed a new gene discovery approach to predict potential developmental genes and identified 275 candidate genes from CNVs detected from both datasets. Based on Mouse Genome Informatics (MGI) and Zebrafish model organism database (ZFIN), 75% of identified genes could lead to developmental defects when mutated. Genes involved in embryonic development, gene transcription, and regulation of biological processes were significantly enriched. Especially, transcription factors and gene families sharing specific protein domains predominated, which included known developmental genes such as HOX, NKX homeodomain genes, and helix-loop-helix containing HAND2, NEUROG2, and NEUROD1 as well as potential novel developmental genes. We observed that developmental genes were denser in certain chromosomal regions, enabling identification of 31 potential genomic loci with clustered genes associated with development.

De Novo Disruption of the Proteasome Regulatory Subunit PSMD12 Causes a Syndromic Neurodevelopmental Disorder.

Degradation of proteins by the ubiquitin-proteasome system (UPS) is an essential biological process in the development of eukaryotic organisms. Dysregulation of this mechanism leads to numerous human neurodegenerative or neurodevelopmental disorders. Through a multi-center collaboration, we identified six de novo genomic deletions and four de novo point mutations involving PSMD12, encoding the non-ATPase subunit PSMD12 (aka RPN5) of the 19S regulator of 26S proteasome complex, in unrelated individuals with intellectual disability, congenital malformations, ophthalmologic anomalies, feeding difficulties, deafness, and subtle dysmorphic facial features. We observed reduced PSMD12 levels and an accumulation of ubiquitinated proteins without any impairment of proteasome catalytic activity. Our PSMD12 loss-of-function zebrafish CRISPR/Cas9 model exhibited microcephaly, decreased convolution of the renal tubules, and abnormal craniofacial morphology. Our data support the biological importance of PSMD12 as a scaffolding subunit in proteasome function during development and neurogenesis in particular; they enable the definition of a neurodevelopmental disorder due to PSMD12 variants, expanding the phenotypic spectrum of UPS-dependent disorders.

Fluorescence In Situ Hybridization Probe Validation for Clinical Use.

In this chapter, we provide a systematic overview of the published guidelines and validation procedures for fluorescence in situ hybridization (FISH) probes for clinical diagnostic use. FISH probes-which are classified as molecular probes or analyte-specific reagents (ASRs)-have been extensively used in vitro for both clinical diagnosis and research. Most commercially available FISH probes in the United States are strictly regulated by the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), the Centers for Medicare & Medicaid Services (CMS) the Clinical Laboratory Improvement Amendments (CLIA), and the College of American Pathologists (CAP). Although home-brewed FISH probes-defined as probes made in-house or acquired from a source that does not supply them to other laboratories-are not regulated by these agencies, they too must undergo the same individual validation process prior to clinical use as their commercial counterparts. Validation of a FISH probe involves initial validation and ongoing verification of the test system. Initial validation includes assessment of a probe's technical specifications, establishment of its standard operational procedure (SOP), determination of its clinical sensitivity and specificity, development of its cutoff, baseline, and normal reference ranges, gathering of analytics, confirmation of its applicability to a specific research or clinical setting, testing of samples with or without the abnormalities that the probe is meant to detect, staff training, and report building. Ongoing verification of the test system involves testing additional normal and abnormal samples using the same method employed during the initial validation of the probe.

Mechanisms for Complex Chromosomal Insertions.

Chromosomal insertions are genomic rearrangements with a chromosome segment inserted into a non-homologous chromosome or a non-adjacent locus on the same chromosome or the other homologue, constituting ~2% of nonrecurrent copy-number gains. Little is known about the molecular mechanisms of their formation. We identified 16 individuals with complex insertions among 56,000 individuals tested at Baylor Genetics using clinical array comparative genomic hybridization (aCGH) and fluorescence in situ hybridization (FISH). Custom high-density aCGH was performed on 10 individuals with available DNA, and breakpoint junctions were fine-mapped at nucleotide resolution by long-range PCR and DNA sequencing in 6 individuals to glean insights into potential mechanisms of formation. We observed microhomologies and templated insertions at the breakpoint junctions, resembling the breakpoint junction signatures found in complex genomic rearrangements generated by replication-based mechanism(s) with iterative template switches. In addition, we analyzed 5 families with apparently balanced insertion in one parent detected by FISH analysis and found that 3 parents had additional small copy-number variants (CNVs) at one or both sides of the inserting fragments as well as at the inserted sites. We propose that replicative repair can result in interchromosomal complex insertions generated through chromothripsis-like chromoanasynthesis involving two or three chromosomes, and cause a significant fraction of apparently balanced insertions harboring small flanking CNVs.

Triploidy mosaicism (45,X/68,XX) in an infant presenting with failure to thrive.

Triploid mosaicism is a rare aneuploidy syndrome characterized by growth retardation, developmental delay, 3-4 syndactyly, microphthalmia, coloboma, cleft lip and/or palate, genitourinary anomalies, and facial or body asymmetry. In the present report, we describe a 3-month-old female presenting with failure to thrive, growth retardation, and developmental delay. A chromosomal microarray demonstrated monosomy X, but her atypical phenotype prompted further evaluation with a chromosome analysis, which demonstrated 45,X/68,XX mixoploidy. To our knowledge, this is the first report of a patient with this chromosome complement. Mosaicism in chromosomal aneuploidies is likely under-recognized and may obscure the clinical diagnosis. At a time when comparative genomic hybridization and genome sequencing are increasingly used as diagnostic tools, this report highlights the clinical utility of chromosome analysis when a molecular diagnosis is not consistent with the observed phenotype.

NUDT21-spanning CNVs lead to neuropsychiatric disease and altered MeCP2 abundance via alternative polyadenylation.

The brain is sensitive to the dose of MeCP2 such that small fluctuations in protein quantity lead to neuropsychiatric disease. Despite the importance of MeCP2 levels to brain function, little is known about its regulation. In this study, we report eleven individuals with neuropsychiatric disease and copy-number variations spanning NUDT21, which encodes a subunit of pre-mRNA cleavage factor Im. Investigations of MECP2 mRNA and protein abundance in patient-derived lymphoblastoid cells from one NUDT21 deletion and three duplication cases show that NUDT21 regulates MeCP2 protein quantity. Elevated NUDT21 increases usage of the distal polyadenylation site in the MECP2 3' UTR, resulting in an enrichment of inefficiently translated long mRNA isoforms. Furthermore, normalization of NUDT21 via siRNA-mediated knockdown in duplication patient lymphoblasts restores MeCP2 to normal levels. Ultimately, we identify NUDT21 as a novel candidate for intellectual disability and neuropsychiatric disease, and elucidate a mechanism of pathogenesis by MeCP2 dysregulation via altered alternative polyadenylation.

Influence of anchoring on miscarriage risk perception associated with amniocentesis.

One factor women consider when deciding whether to pursue amniocentesis is the risk of miscarriage. People use mechanisms like anchoring, or the prior belief regarding the magnitude of risk, as a frame of reference for new information. This study aimed to determine a woman's perception of miscarriage risk associated with amniocentesis before and after genetic counseling and to determine what factors anchor a woman's perception of miscarriage risk. One hundred thirteen women being seen for prenatal genetic counseling and possible amniocentesis at six Houston clinics participated in the two-part anonymous survey. While most women (56.7 %) perceived the risk as low or average pre-counseling and indicated the numeric risk of amniocentesis as <1 %, significantly more patients (73 %) correctly identified the numeric risk as <1 % post-counseling (p < 0.0001). However, the majority of patients' qualitative risk perception did not change after the genetic counseling session (60 %). Those who changed their feeling about the risk after counseling showed a decreased perception of the risk (p < 0.0001). Participants who elected amniocentesis had a significantly lower perception of the risk (p = 0.017) whereas those who declined amniocentesis were more likely to view the risk as high (p = 0.004). The only two anchoring factors that had an effect were having a friend or relative with a personal or family history of a genetic disorder (p = 0.001) and having a child already (p = 0.038); both were associated with a lower risk perception. The lack of significant factors may reflect the uniqueness of each patient's risk assessment framework and reinforces the importance of genetic counseling to elucidate individual concerns, particularly as non-invasive prenatal testing becomes more widely available and further complicates the prenatal testing landscape.

Neurodevelopmental and neurobehavioral characteristics in males and females with CDKL5 duplications.

Point mutations and genomic deletions of the CDKL5 (STK9) gene on chromosome Xp22 have been reported in patients with severe neurodevelopmental abnormalities, including Rett-like disorders. To date, only larger-sized (8-21 Mb) duplications harboring CDKL5 have been described. We report seven females and four males from seven unrelated families with CDKL5 duplications 540-935 kb in size. Three families of different ethnicities had identical 667kb duplications containing only the shorter CDKL5 isoform. Four affected boys, 8-14 years of age, and three affected girls, 6-8 years of age, manifested autistic behavior, developmental delay, language impairment, and hyperactivity. Of note, two boys and one girl had macrocephaly. Two carrier mothers of the affected boys reported a history of problems with learning and mathematics while at school. None of the patients had epilepsy. Similarly to CDKL5 mutations and deletions, the X-inactivation pattern in all six studied females was random. We hypothesize that the increased dosage of CDKL5 might have affected interactions of this kinase with its substrates, leading to perturbation of synaptic plasticity and learning, and resulting in autistic behavior, developmental and speech delay, hyperactivity, and macrocephaly.