The prevalence of developmental disabilities in Taiwan remains unclear, especially in young children under the age 3. We aimed to study the prevalence of developmental disabilities and verify a useful developmental screening tool in a community setting in Taiwan. We conducted a prospective cross-sectional study in northeastern Taiwan from July 2008 to December 2009 in children aged 4 months to 6 years old from well-child visits. We devised a screening program using Taipei City Developmental Screening Checklist for Preschoolers, 2nd Version (Taipei-II), a validated parent-report milestone checklist tailored to the Taiwanese culture and language to assess the prevalence of developmental disabilities in Taiwan. Information about the children's medical conditions and their family were recorded. A total of 3214 children were recruited, of whom 365 had developmental disabilities, with an overall prevalence of 11.36%. Speech and language delay/disorders were the most common developmental problems followed by motor delays, with prevalence rates of 4.79% and 2.33%, respectively. Low economic status, prematurity and/or small for gestational age and a history of perinatal hypoxia or underlying medical disorders were the main risk factors correlated with developmental delays. However, foreign-born mother and aboriginal families were not important factors for poor developmental outcomes. The prevalence rate of developmental disabilities in northeastern Taiwan was 11.36%. Low economic status, prematurity and/or small for gestational age and a history of underlying medical disorders were the main risk factors correlated with developmental disabilities. Taipei II is an easy-to-use and effective developmental surveillance tool for Taiwanese children.

Unexplained global developmental delay (GDD) and intellectual disabilities (ID) together affect nearly 2% of the pediatric population. Establishing an etiologic diagnosis is crucial for disease management, prognostic evaluation, and provision of physical and psychological support for both the patient and the family. Advancements in genome sequencing have allowed rapid accumulation of gene–disorder associations and have accelerated the search for an etiologic diagnosis for unexplained GDD/ID. We reviewed recent studies that utilized genome-wide analysis technologies, and we discussed their diagnostic yield, strengths, and limitations. Overall, exome sequencing (ES) and genome sequencing (GS) outperformed chromosomal microarrays and targeted panel sequencing. GS provides coverage for both ES and chromosomal microarray regions, providing the maximal diagnostic potential, and the cost of ES and reanalysis of ES-negative results is currently still lower than that of GS alone. Therefore, singleton or trio ES is the more cost-effective option for the initial investigation of individuals with GDD/ID in clinical practice compared to a staged approach or GS alone. Based on these updated evidence, we proposed an evaluation algorithm with ES as the first-tier evaluation for unexplained GDD/ID.

This study aimed to clarify whether brain-derived neurotrophic factor (BDNF) is a biomarker for cognitive dysfunction in children with type 1 diabetes. We conducted a cross-sectional case-control study of children aged between 6 and 18 years with type 1 diabetes and healthy volunteers. Serum BDNF level was measured in all of the studied children, and they all underwent intelligence tests with the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV). We further compared the cognitive function and BDNF levels in the diabetic children with positive glutamic acid decarboxylase 65 antibody (GAD65-Ab) and those with negative GAD65-Ab. Forty-five children with type 1 diabetes (mean age 14.0 ± 2.6 years, 42% male) and 50 normal controls (mean age 13.2 ± 2.3 years, 54% male) were recruited. The serum BDNF level was significantly lower in the diabetes group than in the controls (15.92 ± 7.2 vs. 18.5 ± 5.1 ng/mL, respectively, t = -2.03, p = 0.045) and much lower in the subgroup with GAD65-Ab positive type 1 diabetes. The average Full-Scale IQ, verbal comprehension, perceptual reasoning and working memory scores in the diabetes group were significantly lower than in the controls (all p < 0.05). Among the children with type 1 diabetes, poor glycemic control was related to lower general cognitive abilities (r = -0.34, p < 0.02), lower verbal comprehension (r = -0.305, p < 0.05), and lower perceptual reasoning scores (r = -0.346, p = 0.02). The children with type 1 diabetes had a lower serum BDNF level and poorer neurocognitive function than normal healthy children, especially those with GAD65-Ab positive diabetes. Poor glycemic control was correlated with worse cognitive performance.

This study aimed to understand the longitudinal relationship between psychosocial stress with tic exacerbation in children with Tourette syndrome (TS) and chronic tic disorder. Consecutive ratings of tic severity as well as child and parental reports of psychosocial stress were obtained for 373 children (296 males, 77 females; mean age 9y 5mo; SD 3y 3mo) with TS and chronic tic disorder between January 2018 and December 2020. The Yale Global Tic Severity Scale (YGTSS) global severity score, total tic score, and impairment rating were calculated. The stressful events and YGTSS measurements were used and treated as time-varying variables in the analyses. Models that controlled for non-independence among the repeated observations using a random intercept and random slope model were employed. Each participant was treated as a random factor in the modelling. Family-related stress, personal relationship stress and school-related stress were independently associated with increasing YGTSS global severity, total tic score, and impairment rating over time. An increased number of stressful events were associated with increased severity of tics. Family, personal relationships, and school-related stress were consistently associated with the exacerbation of tics. Managing these stressful events is important in the treatment of TS and chronic tic disorder.

Background: Lesch–Nyhan syndrome (LNS) is a rare X-linked recessive metabolic disorder caused by mutations in the HPRT1 gene, resulting in hypoxanthine–guanine phosphoribosyltransferase (HPRT) deficiency. Early diagnosis is critical for optimizing management and improving outcomes. This study presents a case series of three Taiwanese patients diagnosed at a single medical center. Methods: Exome sequencing and biochemical testing were used to confirm the diagnoses. Early clinical manifestations, including hyperuricemia, hypotonia, and developmental delay, were documented during the initial stages of the disease. Results: All three patients had hyperuricemia, hypotonia, spasticity, and motor developmental delay. Pathogenic variants in the HPRT1 gene were identified in two patients, while the third was confirmed by biochemical testing. Two patients had orange-colored crystalline deposits in their diapers, indicative of hyperuricosuria. Self-injurious behavior had not yet developed in two patients due to their young age. Conclusions: Early clinical features such as hyperuricemia, hypotonia, and motor delay may suggest LNS in infancy. Molecular genetic testing, particularly whole exome sequencing, can facilitate an early diagnosis before specific manifestations occur, enabling timely interventions and improving patient outcomes.