Genetic Testing for Global Developmental Delay in Early Childhood.

Importance: Global developmental delay (GDD) is characterized by a complex etiology, diverse phenotypes, and high individual heterogeneity, presenting challenges for early clinical etiologic diagnosis. Cognitive impairment is the core symptom, and despite the pivotal role of genetic factors in GDD development, the understanding of them remains limited. Objectives: To assess the utility of genetic detection in patients with GDD and to examine the potential molecular pathogenesis of GDD to identify targets for early intervention. Design, Setting, and Participants: This multicenter, prospective cohort study enrolled patients aged 12 to 60 months with GDD from 6 centers in China from July 4, 2020, to August 31, 2023. Participants underwent trio whole exome sequencing (trio-WES) coupled with copy number variation sequencing (CNV-seq). Bioinformatics analysis was used to unravel pathogenesis and identify therapeutic targets. Main Outcomes and Measures: The main outcomes of this study involved enhancing the rate of positive genetic diagnosis for GDD, broadening the scope of genetic testing indications, and investigating the underlying pathogenesis. The classification of children into levels of cognitive impairment was based on the developmental quotient assessed using the Gesell scale. Results: The study encompassed 434 patients with GDD (262 [60%] male; mean [SD] age, 25.75 [13.24] months) with diverse degrees of cognitive impairment: mild (98 [23%]), moderate (141 [32%]), severe (122 [28%]), and profound (73 [17%]). The combined use of trio-WES and CNV-seq resulted in a 61% positive detection rate. Craniofacial abnormalities (odds ratio [OR], 2.27; 95% CI, 1.45-3.56), moderate or severe cognitive impairment (OR, 1.69; 95% CI, 1.05-2.70), and age between 12 and 24 months (OR, 1.57; 95% CI, 1.05-2.35) were associated with a higher risk of carrying genetic variants. Additionally, bioinformatics analysis suggested that genetic variants may induce alterations in brain development and function, which may give rise to cognitive impairment. Moreover, an association was found between the dopaminergic pathway and cognitive impairment. Conclusions and Relevance: In this cohort study of patients with GDD, combining trio-WES with CNV-seq was a demonstrable, instrumental strategy for advancing the diagnosis of GDD. The close association among genetic variations, brain development, and clinical phenotypes contributed valuable insights into the pathogenesis of GDD. Notably, the dopaminergic pathway emerged as a promising focal point for potential targets in future precision medical interventions for GDD.

[Clinical features and genetic analysis of a child with EAST/SeSAME syndrome].

OBJECTIVE: To explore the genetic basis for a EAST/SeSAME syndrome child featuring epilepsy, ataxia, sensorineural deafness and intellectual disability. METHODS: A child with EAST/SeSAME syndrome who had presented at the Third Affiliated Hospital of Zhengzhou University in January 2021 was selected as the study object. Peripheral blood samples of the child and her parents were collected and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. RESULTS: Genetic testing revealed that the child has harbored compound heterozygous variants of the KCNJ10 gene, namely c.557T>C (p.Val186Ala) and c.386T>A (p.Ile129Asn), which were inherited from her mother and father, respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted as likely pathogenic (PM1+PM2_Supporting+PP3+PP4; PM1+PM2_Supporting+PM3+PP3+PP4). CONCLUSION: The patient was diagnosed with EAST/SeSAME syndrome due to the compound heterozygous variants of the KCNJ10 gene.

[Analysis of CYP2U1 gene variants in a child with Hereditary spastic paraplegia type 56].

OBJECTIVE: To analyze the clinical phenotype and genetic characteristics of a child with Hereditary spastic paraplegia (HSP). METHODS: A child with HSP who was admitted to the Third Affiliated Hospital of Zhengzhou University on August 10, 2020 due to discovery of tiptoeing for 2 years was selected as the study subject, and relevant clinical data was collected. Peripheral blood samples of the child and her parents were collected for the extraction of genomic DNA. And trio-whole exome sequencing (trio-WES) was carried out. Candidate variants were verified by Sanger sequencing. Bioinformatic software was used to analyze the conservation of variant sites. RESULTS: The child was a 2-year-and-10-month-old female with clinical manifestations including increased muscle tone of lower limbs, pointed feet, and cognitive language delay. Trio-WES results showed that she had harbored compound heterozygous variants of c.865C>T (p.Gln289*) and c.1126G>A (p.Glu376Lys) of the CYP2U1 gene. And the corresponding amino acid for c.1126G>A (p.Glu376Lys) is highly conserved among various species. Based on guidelines from the American College of Medical Genetics and Genomics, the c.865C>T was predicted as a pathogenic variant (PVS1+PM2_Supporting), and c.1126G>A was rated as a variant of uncertain significance (PM2_Supporting+PM3+PP3). CONCLUSION: The child was diagnosed with HSP type 56 due to compound variants of the CYP2U1 gene. Above findings have enriched the mutation spectrum of the CYP2U1 gene.

[Analysis of NOVA2 gene variant in a child with Neurodevelopmental disorder with or without autistic features and/or structural brain abnormalities].

OBJECTIVE: To explore the genetic basis for a child with Neurodevelopmental disorder with or without autistic features and/or structural brain abnormalities (NEDASB). METHODS: A child with NEDASB who presented at the Third Affiliated Hospital of Zhengzhou University in July 2021 was selected as the subject. Peripheral blood samples of the child and her parents were collected and subjected to high-throughput sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The child was found to harbor a heterozygous c.820_828delinsCTTCA (p.Thr274Leufs*121) variant of the NOVA2 gene, for which both of her parents were of wild type. The variant was predicted as pathogenic based on the guidelines from the American College of Medical Genetics and Genomics. CONCLUSION: The heterozygous c.820_828delinsCTTCA (p.Thr274Leufs*121) variant of the NOVA2 gene probably underlay the disease in this child. Above finding has enriched the spectrum of NOVA2 gene variants and provided a basis for genetic counseling and prenatal diagnosis for this family.

[Effect of rehabilitation treatment based on the ICF-CY Core Sets on activities of daily living in children with cerebral palsy: a prospective randomized controlled study].

OBJECTIVE: To study the effect of rehabilitation treatment based on the International Classification of Functioning, Disability and Health-Children and Youth Version (ICF-CY) Core Sets on activities of daily living in children with cerebral palsy. METHODS: The children with cerebral palsy were divided into an observation group (n=63) and a control group (n=59) using a random number table. The children in the observation group were evaluated using the brief ICF-CY Core Sets for children under 6 years to identify intervention targets and develop rehabilitation plans and goals, and then specific methods were selected for rehabilitation treatment. The children in the control group were evaluated and treated with the traditional rehabilitation mode. The scores of the Functional Independence Measure for Children (WeeFIM) and the Infants-Junior Middle School Students' Social-Life Abilities Scale were assessed for both groups before treatment and after three courses of treatment. The intervention of environmental factors was compared between the two groups. RESULTS: There was no significant difference in the scores of the WeeFIM and Social-Life Abilities scales between the two groups before treatment (P > 0.05). After treatment, both groups had significant increases in the scores of the WeeFIM and Social-Life Abilities scales (P < 0.001). The observation group had significantly higher scores of WeeFIM and Social-Life Abilities scales than the control group after treatment (P < 0.05). There was no significant difference in the use rate of orthosis between the two groups (P > 0.05), but the use rate of assistive devices for self-help, transfer and communication, the rate of facility renovation, and the rate of family rehabilitation guidance in the observation group were significantly higher than those in the control group (P < 0.05). CONCLUSIONS: The rehabilitation treatment regimen for cerebral palsy based on the CF-CY Core Sets pays more attention to the influence of environmental factors in the process of rehabilitation and can effectively improve the activities of daily living of children with cerebral palsy.

[Autosomal dominant intellectual disability-40 caused by a de novo mutation of the CHAMP1 gene: a case report].

A boy, aged 6 months, had the manifestations of intellectual and motor developmental delay, head instability, general weakness, unawareness of grasping objects by hands, and unusual facies (slightly wide eye distance, epicanthus, esotropia, mouth-opening appearance, short philtrum, and low-set ears). Gene detection results showed a de novo heterozygous frameshift mutation of the CHAMP1 gene at the chromosomal location of chr13:115089847, and nuclear acid was changed to c.530delCinsTTT, resulting in a change in amino acid to p.S177Ffs*2. Therefore, the boy was diagnosed with autosomal dominant intellectual disability-40 caused by the mutation in the CHAMP1 gene. This case report suggests that for children with unexplained intellectual disability, especially those with generalized hypotonia and severe language disorder, the possibility of CHAMP1 gene mutation should be considered, and genetic testing should be performed as early as possible.

[Effect of botulinum toxin A injection in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy: a prospective study].

OBJECTIVE: To investigate the long-term clinical efficacy and adverse effects of botulinum toxin-A (BTX-A) injection in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy. METHODS: Eighty children aged 9-36 months with cerebral palsy and gastrocnemius spasticity were selected and randomly divided into a BTX-A injection group and a conventional treatment group (n=40 each). The children in the BTX-A injection group received injections of BTX-A guided by color Doppler ultrasound and 4 courses of rehabilitation training after injection. Those in the conventional treatment group received 4 courses of the same rehabilitation training alone. Before treatment and at 1, 2, 3, and 6 months after treatment, the modified Tardieu scale (MTS) was applied to assess the degree of gastrocnemius spasticity, the values in the passive state measured by surface electromyography (sEMG) were applied to evaluate muscle tension, and the Gross Motor Function Measure (GMFM) was used to evaluate gross motor function. RESULTS: Compared with the conventional treatment group, the BTX-A injection group had significantly greater reductions in MTS score and the values in the passive state measured by sEMG (P<0.05), as well as significantly greater increases in joint angles R1 and R2 in MTS and gross motor score in GMFM (P<0.05). No serious adverse reactions related to BTX-A injection were found. CONCLUSIONS: BTX-A injection is effective and safe in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy.

[Therapeutic effects of different doses of botulinum toxin A injection on tiptoe deformation in children with cerebral palsy].

OBJECTIVE: To study the therapeutic effects of different doses of botulinum toxin A (BTX-A) injection on tiptoe deformation in children with cerebral palsy. METHODS: A total of 256 children with tiptoe deformation due to spastic cerebral palsy were classified into group A (muscle tension levels I-II, n=147) and group B (muscle tension levels III-IV, n=109). Group A was randomly divided into group A1 (injected with high-dose BTX-A, n=73) and group A2 (injected with low-dose BTX-A, n=74). Group B was randomly divided into group B1 (injected with high-dose BTX-A, n=55) and group B2 ( injected with low-dose BTX-A, n=54). The dose of BTX-A was 6 U/kg for groups A1 and B1 and was 3 U/kg for groups A2 and B2. Before the injection and at 1,2,6, and 12 months after injection, the muscle tension of limbs was evaluated with the modified Ashworth Scale, and the recovery of motor function of lower limbs was assessed with the Gross Motor Function Measure (GMFM). RESULTS: Before and after treatment, there were no significant differences in Ashworth and GMFM scores between groups A1 and A2 (P>0.05). After treatment, group B1 had a significantly reduced Ashworth score and a significantly increased GMFM score, and group B1 had a significantly lower Ashworth score and a significantly higher GMFM score compared with group B2 (P<0.05). For groups A and B, Ashworth score gradually declined post-treatment, reached the lowest point at 3 months after treatment, and returned to the level before treatment at 12 months after treatment; GMFM score gradually increased post-treatment and reached the peak level at 12 months after treatment (P<0.05). CONCLUSIONS: The level of muscle tension should be considered when BTX-A injection is used for treating tiptoe deformation in children with cerebral palsy. It makes no difference to use high- or low-dose BTX-A when the muscle tension level is within I-II, but high-dose BTX-A has a better performance in reducing muscle tension and improving motor function when the muscle tension level is within III-IV.