ABSTRACT
Epidemiologic studies of birth defects often conduct separate analyses for cases that have isolated defects (e.g., spina bifida only) and cases that have multiple defects (e.g., spina bifida and a congenital heart defect). However, in some instances, cases with additional defects (e.g., spina bifida and clubfoot) may be more appropriately considered as isolated because the co-occurring defect (clubfoot) is believed to be developmentally related to the defect of interest. Determining which combinations should be considered isolated can be challenging and potentially resource intensive for registries. Thus, we developed automated classification procedures for differentiating between isolated versus multiple defects, while accounting for developmentally related defects, and applied the approach to data from the Texas Birth Defects Registry (1999-2018 deliveries). Among 235,544 nonsyndromic cases in Texas, 89% of cases were classified as having isolated defects, with proportions ranging from 25% to 92% across 43 specific defects analyzed. A large proportion of isolated cases with spina bifida (44%), lower limb reduction defects (44%), and holoprosencephaly (32%) had developmentally related defects. Overall, our findings strongly support the need to account for isolated versus multiple defects in risk factor association analyses and to account for developmentally related defects when doing so, which has implications for interpreting prior studies.
ABSTRACT
Structural birth defects that occur in infants with syndromes may be etiologically distinct from those that occur in infants in whom there is not a recognized pattern of malformations; however, population-based registries often lack the resources to classify syndromic status via case reviews. We developed criteria to systematically identify infants with suspected syndromes, grouped by syndrome type and level of effort required for syndrome classification (e.g., text search). We applied this algorithm to the Texas Birth Defects Registry (TBDR) to describe the proportion of infants with syndromes delivered during 1999-2014. We also developed a bias analysis tool to estimate the potential percent bias resulting from including infants with syndromes in studies of risk factors. Among 207,880 cases with birth defects in the TBDR, 15% had suspected syndromes and 85% were assumed to be nonsyndromic, with a range across defect types from 28.5% (atrioventricular septal defects) to 98.9% (pyloric stenosis). Across hypothetical scenarios varying expected parameters (e.g., nonsyndromic proportion), the inclusion of syndromic cases in analyses resulted in up to 50.0% bias in prevalence ratios. In summary, we present a framework for identifying infants with syndromic conditions; implementation might harmonize syndromic classification across registries and reduce bias in association estimates.
Subject(s)
Congenital Abnormalities , Heart Septal Defects , Infant , Humans , Syndrome , Prevalence , Registries , Texas/epidemiology , Congenital Abnormalities/diagnosis , Congenital Abnormalities/epidemiology , Congenital Abnormalities/geneticsABSTRACT
Whole-exome sequencing of 13 individuals with developmental delay commonly accompanied by abnormal muscle tone and seizures identified de novo missense mutations enriched within a sub-region of GNB1, a gene encoding the guanine nucleotide-binding protein subunit beta-1, Gß. These 13 individuals were identified among a base of 5,855 individuals recruited for various undiagnosed genetic disorders. The probability of observing 13 or more de novo mutations by chance among 5,855 individuals is very low (p = 7.1 × 10(-21)), implicating GNB1 as a genome-wide-significant disease-associated gene. The majority of these 13 mutations affect known Gß binding sites, which suggests that a likely disease mechanism is through the disruption of the protein interface required for Gα-Gßγ interaction (resulting in a constitutively active Gßγ) or through the disruption of residues relevant for interaction between Gßγ and certain downstream effectors (resulting in reduced interaction with the effectors). Strikingly, 8 of the 13 individuals recruited here for a neurodevelopmental disorder have a germline de novo GNB1 mutation that overlaps a set of five recurrent somatic tumor mutations for which recent functional studies demonstrated a gain-of-function effect due to constitutive activation of G protein downstream signaling cascades for some of the affected residues.
Subject(s)
Developmental Disabilities/etiology , GTP-Binding Protein beta Subunits/genetics , Germ-Line Mutation/genetics , Intellectual Disability/etiology , Muscle Hypotonia/etiology , Seizures/etiology , Adolescent , Adult , Child , Child, Preschool , Developmental Disabilities/pathology , Exome/genetics , Female , GTP-Binding Protein beta Subunits/chemistry , Humans , Infant , Intellectual Disability/pathology , Male , Muscle Hypotonia/pathology , Phenotype , Protein Conformation , Seizures/pathology , Signal Transduction , Young AdultABSTRACT
Type 1 Gaucher disease (GD) is the most common lysosomal storage disorder. Previously, treatment for GD was limited to intravenous enzyme replacement therapies (ERTs). More recently, oral substrate reduction therapies (SRTs) were approved for treatment of GD. Although both therapies alleviate disease symptoms, attitudes toward SRTs and patient perceptions of health while using SRT have not been well established. Electronic surveys were administered to adults with GD and asked about treatment history, attitudes toward SRTs, and perception of health while using SRTs as compared to ERTs, if applicable to the participant. ERT users that were offered treatment with SRTs cited potential side effects, wanting more research on SRTs, and satisfaction with their current treatment regimen as reasons for declining SRTs. SRT users expressed convenience and less invasiveness as reasons for choosing SRTs. Additionally, those using SRTs most often perceived their health to be similar to when they previously used ERT. Participant responses illustrate that attitudes toward SRTs can be variable and that one particular treatment may not be ideal for all patients with GD depending on individual perceptions of factors such as convenience, invasiveness, or side effects. Thus, individuals with GD should be counseled adequately by healthcare providers about both ERTs and SRTs for treatment of GD now that SRTs are clinically available.
Subject(s)
Attitude to Health , Enzyme Replacement Therapy/methods , Enzyme Replacement Therapy/psychology , Gaucher Disease/drug therapy , Gaucher Disease/psychology , Adult , Glucosylceramidase , HumansABSTRACT
Disorders resulting from 5p deletions (5p-) were first recognized by Lejeune et al. in 1963 [Lejeune et al. (1963); C R Hebd Seances Acad Sci 257:3098-3102]. 5p- is caused by partial or total deletion of the short arm of chromosome 5. The most recognizable phenotype is characterized by a high-pitched cry, dysmorphic features, poor growth, and developmental delay. This report reviews 5p- disorders and their molecular basis. Hemizygosity for genes located within this region have been implicated in contributing to the phenotype. A review of the genes on 5p which may be dosage sensitive is summarized. Because of the growing knowledge of these specific genes, future directions to explore potential targeted therapies for individuals with 5p- are discussed. © 2015 Wiley Periodicals, Inc.
Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 5/genetics , Developmental Disabilities/genetics , Developmental Disabilities/therapy , Developmental Disabilities/diagnosis , Humans , PhenotypeABSTRACT
Background: Birth defects are a leading cause of neonatal, infant, and childhood mortality, but recent population-based survival estimates for a spectrum in the U.S. are lacking. Methods: Using the statewide Texas Birth Defects Registry (1999-2017 births) and vital records linkage to ascertain deaths, we conducted Kaplan-Meier analyses to estimate survival probabilities at 1, 7, and 28 days, and 1, 5, and 10 years. We evaluated survival in the full cohort of infants with any major defect and for 30 specific conditions. One-year survival analyses were stratified by gestational age, birth year, and case classification. Findings: Among 246,394 live-born infants with any major defect, the estimated survival probabilities were 98.9% at 1 day, 95.0% at 1 year, and 93.9% at 10 years. Ten-year survival varied by condition, ranging from 36.9% for holoprosencephaly to 99.3% for pyloric stenosis. One-year survival was associated with increasing gestational age (e.g., increasing from 46.9% at <28 weeks to 95.8% at ≥37 weeks for spina bifida). One-year survival increased in more recent birth years for several defect categories (e.g., increasing from 86.0% among 1999-2004 births to 93.1% among 2014-2017 births for unilateral renal agenesis/dysgenesis) and was higher among infants with an isolated defect versus those with multiple defects. Interpretation: This study describes short- and long-term survival outcomes from one of the largest population-based birth defect registries in the world and highlights improved survival over time for several conditions. Our results may lend insight into future healthcare initiatives aimed at reducing mortality in this population. Funding: This study was funded in part by a Centers for Disease Control and Prevention (CDC) birth defects surveillance cooperative agreement with the Texas Department of State Health Services and Health Resources and Services Administration (HRSA) Block Grant funds.