Chijioke Ikomi

Background: 48,XXYY syndrome is a rare sex chromosome aneuploidy (SCA) characterized by neurodevelopmental deficits and medical comorbidities. The limited information available in the literature is almost exclusively limited to postnatally diagnosed cases. This study aims to describe the early medical and developmental features of prenatally identified 48,XXYY infants, with comparisons to 47,XYY, 47,XXY cohorts, and typical populations, as well as previously reported postnatally diagnosed 48,XXYY cases. Methods: The eXtraordinarY Babies Study prospectively follows children prenatally identified to be at high risk for SCA with annual medical and neurodevelopmental evaluations. Data presented herein include the prevalence of medical conditions, developmental milestones, developmental and adaptive functioning assessment scores, and therapy utilization in participants confirmed to have 48,XXYY. Comparisons were made between this cohort and the typical population, infants with 47,XYY and 47,XXY also enrolled in the eXtraordinarY Babies Study, and a 2008 cohort of individuals postnatally identified 48,XXYY. Results: Infants with 48,XXYY exhibited a range of early medical features, including high rates of feeding and GI disorders (breastfeeding difficulties, gastroesophageal reflux, and eosinophilic esophagitis), allergic disorders (food allergies and environmental allergies), and hypotonia. Developmental and adaptive functioning scores indicated delays in motor, communication, and social domains, with nearly all infants receiving speech therapy, physical and/or occupational therapy. Comparisons with the 47,XYY and 47,XXY cohorts revealed more medical and developmental challenges in the 48,XXYY group, however there was variability and some overlap with both the general population and sex chromosome trisomy conditions. Additionally, comparison to the 2008 postnatally identified 48,XXYY cohort indicated that while prenatal diagnosis allowed for earlier intervention, developmental outcomes in the first years of life were similar between the two groups. Conclusions: 48,XXYY diagnosed prenatally facilitates early monitoring, anticipatory guidance, and proactive referrals for medical evaluations and intervention, given developmental delays and medical challenges are more common in infancy and early childhood compared to the general population and trisomy SCAs. These findings provide valuable insights for genetic counselors and healthcare providers, emphasizing the spectrum of medical and developmental findings and importance of early and proactive care to support individual outcomes. Prospective study of this prenatally identified cohort will provide important natural history and phenotypic variability in XXYY, as well as identification of predictors of health and developmental outcomes.

Sex chromosome aneuploidies (SCAs), including Klinefelter syndrome (47,XXY), Turner syndrome (45,X), XYY syndrome, trisomy X (47,XXX), and rarer tetrasomies and pentasomies, affect approximately 1 in 400 births and are associated with a wide range of developmental, cognitive, and physical health outcomes. While clinical research on SCAs has expanded over the past two decades, it is unclear whether the populations included in these studies reflect the demographic diversity of those affected. Assessing representation is critical to ensuring research findings are generalizable and applicable to diverse patient populations. We conducted a systematic review of global clinical research on SCAs published in English between January 2004 and May 2024. Searches were performed in Ovid MEDLINE ALL, Embase, and Web of Science. Studies were included if they enrolled ≥ 10 participants and excluded if they were case reports, reviews, or meta‐analyses. We extracted data from 1474 studies on geographic location, participant karyotypes, and demographic metrics, including race, ethnicity, and socioeconomic status (SES) reported. Trends in demographic reporting were examined over time and by geographic region. For US‐based studies reporting race/ethnicity, we compared pooled participant demographics to national census data. SCA research is concentrated within a small number of geographic areas, primarily in Europe (51.4%) and the United States (23.6%). Reporting rates of race or ethnicity for US papers increased over the 20‐year observation period, with an average increase of 1.5% ± 0.4% per year ( p = 0.003), peaking in 2024 with 61.4% of US‐based papers presenting demographics. When reported, studies consistently overrepresented White non‐Hispanic ( p < 0.001) and college‐educated ( p < 0.001) participants relative to US census benchmarks. This systematic review reveals persistent gaps in the demographic reporting and representation of participants in SCA research. Even in the United States, where population diversity is high, published studies do not reflect the expected racial, ethnic, and socioeconomic makeup of affected individuals. To ensure that research findings are equitable and clinically relevant, future studies should adopt standardized demographic reporting and prioritize inclusive enrollment strategies to reflect the full spectrum of individuals with SCAs.

Individuals with Turner syndrome (TS) are known to be at increased risk for neurodevelopmental disorders (NDD) and mental health (MH) conditions, but data from large, population‐based pediatric samples remain limited. We examined the prevalence of NDD and MH diagnoses among youth with TS ( N = 2145) compared to matched female controls ( N = 8580) across six US pediatric health systems. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using generalized estimating equations. Youth with TS had significantly higher odds of an NDD diagnosis (24.2% vs. 11.9%; OR 2.37, 95% CI 2.11–2.67), particularly for speech‐language, motor, learning, and attentional disorders. Increased odds were also observed for autism spectrum disorder (ASD) and intellectual developmental disorder (IDD), though these remained relatively uncommon. In contrast, MH diagnoses, such as anxiety and mood disorders, were not more prevalent in TS compared to controls (17.3% vs. 18.5%; OR 0.92, 95% CI 0.81–1.05). These findings support the need for proactive neurodevelopmental screening in TS and raise important questions about the recognition and documentation of MH conditions in this population. Additional research is warranted to understand whether MH symptoms are underdiagnosed, present differently, or emerge later in development in youth with TS.

Individuals with Turner syndrome (TS) are known to be at increased risk for neurodevelopmental disorders (NDD) and mental health (MH) conditions, but data from large, population-based pediatric samples remain limited. We examined the prevalence of NDD and MH diagnoses among youth with TS (N = 2,145) compared to matched female controls (N = 8,580) across six U.S. pediatric health systems. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using generalized estimating equations. Youth with TS had significantly higher odds of an NDD diagnosis (24.2% vs. 11.9%; OR 2.37, 95% CI 2.11–2.67), particularly for speech-language, motor, learning, and attentional disorders. Increased odds were also observed for autism spectrum disorder (ASD) and intellectual developmental disorder (IDD), though these remained relatively uncommon. In contrast, MH diagnoses, such as anxiety and mood disorders, were not more prevalent in TS compared to controls (17.3% vs. 18.5%; OR 0.92, 95% CI 0.81–1.05). These findings support the need for proactive neurodevelopmental screening in TS and raise important questions about the recognition and documentation of MH conditions in this population. Additional research is warranted to understand whether MH symptoms are underdiagnosed in youth with TS or emerge later in development.

Background Sex chromosome aneuploidies (SCAs), including Klinefelter syndrome (47,XXY), Turner syndrome (45,X), XYY syndrome, trisomy X (47,XXX), and rarer tetrasomies and pentasomies, affect approximately 1 in 400 births and are associated with a wide range of developmental, cognitive, and physical health outcomes. While clinical research on SCAs has expanded over the past two decades, it is unclear whether the populations included in these studies reflect the demographic diversity of those affected. Assessing representation is critical to ensuring research findings are generalizable and applicable to diverse patient populations. Methods We conducted a systematic review of global clinical research on SCAs published in English between January 2004 and May 2024. Searches were performed in Ovid MEDLINE® ALL, Embase, and Web of Science. Studies were included if they enrolled ≥10 participants and excluded if they were case reports, reviews, or meta-analyses. We extracted data from 1,474 studies on geographic location, participant karyotypes, and demographic metrics, including race, ethnicity, and socioeconomic status (SES) reported. Trends in demographic reporting were examined over time and by geographic region. For U.S.-based studies reporting race/ethnicity, we compared pooled participant demographics to national census data. Results SCA research is concentrated within a small number of geographic areas, primarily in Europe (51.4%) and the U.S. (23.6%). Reporting rates of race or ethnicity for U.S. papers increased over the 20-year observation period, with an average increase of 1.5% ± 0.4% per year (p = 0.003), peaking in 2024 with 61.4% of U.S.-based papers presenting demographics. When reported, studies consistently overrepresented non-Hispanic White (pConclusions This systematic review reveals persistent gaps in the demographic reporting and representation of participants in SCA research. Even in the U.S., where population diversity is high, published studies do not reflect the expected racial, ethnic, and socioeconomic makeup of affected individuals. To ensure that research findings are equitable and clinically relevant, future studies should adopt standardized demographic reporting and prioritize inclusive enrollment strategies to reflect the full spectrum of individuals with SCAs.

Background and objectives Sex chromosome trisomy (SCT) is a common chromosomal abnormality associated with increased risks for early developmental delays and neurodevelopmental disorders later in childhood. Our objective was to quantify the spectrum of early developmental milestones in SCT. We hypothesized later milestone achievement in SCT than the general population. Methods Data were collected as part of the eXtraordinarY Babies Study, a prospective natural history of developmental and health trajectories in a prenatally identified sample of infants with SCT. Parent reported, clinician-validated, early motor and language milestones were collected at 2, 6, 12, 18, 24, and 36-months. Age distributions of milestone achievement were compared with normative data. Results In all SCT conditions, compared with normative data, there was increased variability and a later median age of skill development across multiple gross motor and expressive language milestones. Results also show a significant amount of overlap with the general pediatric population, suggesting that for many children with prenatally identified SCT, early milestones present within, or close to, the expected timeline. Conclusions As increasing numbers of infants with prenatal SCT diagnoses present at pediatric practices, we provide an evidence-based schedule of milestone achievement in SCT as a tool for pediatricians and families. Detailed data on SCT milestones can support clinical interpretation of milestone achievement. Increased variability and later median age of milestone acquisition in SCT compared to norms support consideration of all infants with SCT as high risk.

Objectives: Lymphedema (LD) in Turner syndrome (TS) is a commonly reported comorbidity, though its associations with karyotype and other comorbidities are poorly understood. Characteristics of patients with TS and LD, including correlation with phenotype and karyotype, are described. Methods: Medical records of patients with TS seen in two pediatric institutions from 2002 to 2020 were retrospectively reviewed. Demographic data (age, presentation onset, clinical features, genetics, LD presence, investigations, treatments) were collected. Results: 393 girls with TS with mean age of 12.5 years (SD: 5.7) were identified. LD was noted in 37 % of patients (n=146). Among the 112 patients with TS and documentation of onset of LD, LD was noted within the first year of life in 78.6 % (n=88). 67.6 % (n=96) of total patients with TS and LD had non-mosaic 45, X karyotype. Frequency of webbed neck was significantly greater in girls with TS and LD compared with girls without LD (58 vs. 7 %, p<0.001). Congenital heart anomalies, hypertension, and renal anomalies were also more common in girls with LD. Nail abnormalities with presence of hypoplastic or dysplastic nails were significantly associated with LD (OR: 6.784, 95 % CI 4.235–11.046). The number of girls reporting presence of LD decreased with age. Conclusions: LD in TS often occurs within the first year of life, is less prevalent in older children and adolescents, and is significantly associated with 45, X karyotype, presence of webbed neck, nail changes, congenital heart anomalies, and renal anomalies.

BACKGROUND AND OBJECTIVE Sex chromosome trisomies (SCT), including XXY, XYY, and XXX syndromes, have been historically underdiagnosed. Noninvasive prenatal cell-free DNA screening has significantly increased identification of these conditions, leading to a need for pediatric care for a growing population of newborns with SCT. Our goal was to analyze and compare perinatal features, medical diagnoses, and physical features in infants with prenatal identification of SCT conditions through the first year of life. METHODS The eXtraordinarY Babies Study is an ongoing, prospective natural history study of prenatally identified children with SCT conducted by interdisciplinary teams in Colorado and Delaware. Participants were enrolled prior to 12 months of age and had pregnancy, birth, medical histories, and physical exams completed by board-certified pediatricians at 2, 6, and/or 12-month visits. Descriptive statistics were followed by comparisons between SCT groups using t-tests or ANOVA, Fisher exact, and correlations between medical features with alpha of 0.05. Relative risks were calculated compared to general population rates. RESULTS 327 infants were included in the analysis (XXY=195, XXX=79, XYY=53). Major congenital anomalies were rare (1.7%). Relative risk compared to general population was elevated for breastfeeding difficulties (51.7%;RR 2.7), positional torticollis (28.2%;RR 7.2), eczema (48.0%;RR 3.5), food allergies (19.3%;RR 2.4), constipation requiring intervention (33.9%;RR 7.6), small cardiac septal defects (7.7%;RR 17.2), and structural renal abnormalities (4.4%;RR 9.7). Inpatient hospitalization was required for 12.4%, with 59.5% of hospitalizations attributable to respiratory infections. DISCUSSION These findings of medical conditions with a higher prevalence can inform anticipatory guidance and medical management for pediatricians caring for infants with SCT. Article Summary Medical findings in largest cohort of prenatally identified infants with XXY, Trisomy X, and XYY from birth to 12 months and implications for pediatric care. What’s Known on This Subject One in ∼500 individuals have an extra X or Y chromosome, or sex chromosome trisomy (SCT). Prenatal screening is now routinely identifying SCT, however there are few studies to guide perinatal and infant care for these individuals. What This Study Adds This prospective observational study presents medical features for 327 infants with prenatally identified SCT from birth through the first year of life. Results identify where proactive screenings and/or interventions may be warranted for infants with SCT.

Context: Diabetes and cardiovascular diseases are common among men with Klinefelter syndrome (KS) and contribute to high morbidity and mortality.Objective: To determine if cardiometabolic-related diagnoses are more prevalent among youth with KS than matched controls in a large population-based cohort.Methods: Secondary data analysis of electronic health records from 6 pediatric institutions in the United States (PEDSnet). Patients included all youth with KS in the database (n = 1080) and 4497 youth without KS matched for sex, age (mean 13 years at last encounter), year of birth, race, ethnicity, insurance, site, and duration of care (mean 7 years). The main outcome measures were prevalence of 5 cardiometabolic-related outcomes: overweight/obesity, dyslipidemia, dysglycemia, hypertension, and liver dysfunction.Results: The odds of overweight/obesity (OR 1.6; 95% CI 1.4-1.8), dyslipidemia (3.0; 2.2-3.9), and liver dysfunction (2.0; 1.6-2.5) were all higher in KS than in controls. Adjusting for covariates (obesity, testosterone treatment, and antipsychotic use) attenuated the effect of KS on these outcomes; however, boys with KS still had 45% greater odds of overweight/obesity (95% CI 1.2-1.7) and 70% greater odds of liver dysfunction (95% CI 1.3-2.2) than controls, and both dyslipidemia (1.6; 1.1-2.4) and dysglycemia (1.8; 1.1-3.2) were higher in KS but of borderline statistical significance when accounting for multiple comparisons. The odds of hypertension were not different between groups.Conclusion: This large, population-based cohort of youth with KS had a higher odds of most cardiometabolic-related diagnoses than matched controls.

BACKGROUND AND OBJECTIVES: Iodine is an essential trace element for maintenance of normal thyroid function. Normal thyroid function is a prerequisite for neurocognitive development and growth in children. In the United States, iodine is not routinely added as a trace element in parenteral nutrition (PN). Our objective was to determine the prevalence of iodine deficiency and hypothyroidism in children on chronic PN. METHODS: This was a cross-sectional study of children 6 months at a tertiary children’s hospital. Primary outcomes were spot urine iodine concentration (UIC), serum thyrotropin, and free thyroxine levels. RESULTS: Twenty-seven patients were identified (74% male). The median age at screening was 48 months (range: 7–213 months). The median duration on PN was 27 months (range: 11–77 months). Seventeen out of 20 patients (85%) were iodine deficient (spot UIC n = 8). None of the children with hypothyroidism screened for autoimmune thyroiditis had positive test results. There was no statistically significant association between duration of PN use and development of iodine deficiency (P = .08) or hypothyroidism (P = .96). CONCLUSIONS: Children on chronic PN are at risk for developing iodine deficiency and resultant hypothyroidism; hence, these children should be screened for these outcomes. Further studies are needed to define the temporal onset of iodine deficiency and timing to thyroid dysfunction related to PN.