Exome sequencing reveals genetic heterogeneity and clinically actionable findings in children with cerebral palsy.

Cerebral palsy (CP) is the most common motor disability in children. To ascertain the role of major genetic variants in the etiology of CP, we conducted exome sequencing on a large-scale cohort with clinical manifestations of CP. The study cohort comprised 505 girls and 1,073 boys. Utilizing the current gold standard in genetic diagnostics, 387 of these 1,578 children (24.5%) received genetic diagnoses. We identified 412 pathogenic and likely pathogenic (P/LP) variants across 219 genes associated with neurodevelopmental disorders, and 59 P/LP copy number variants. The genetic diagnostic rate of children with CP labeled at birth with perinatal asphyxia was higher than the rate in children without asphyxia (P = 0.0033). Also, 33 children with CP manifestations (8.5%, 33 of 387) had findings that were clinically actionable. These results highlight the need for early genetic testing in children with CP, especially those with risk factors like perinatal asphyxia, to enable evidence-based medical decision-making.

Bioinformatics-based discovery of biomarkers and immunoinflammatory targets in children with cerebral palsy: An observational study.

Cerebral palsy (CP) is the most common disabling disease in children, and motor dysfunction is the core symptom of CP. Although relevant risk factors have been found to be closely associated with CP: congenital malformations, multiple gestation, prematurity, intrauterine inflammation and infection, birth asphyxia, thrombophilia, and perinatal stroke. Its important pathophysiological mechanism is amniotic fluid infection and intraamniotic inflammation leading to fetal developing brain damage, which may last for many years. However, the molecular mechanism of CP is still not well explained. This study aimed to use bioinformatics to identify key biomarker-related signaling pathways in CP. The expression profile of children with CP was selected from the Gene Expression Comprehensive Database, and the CP disease gene data set was obtained from GeneCards. A protein-protein interaction network was established and functional enrichment analysis was performed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. A total of 144 differential key intersection genes and 10 hub genes were identified through molecular biology. Gene Ontology functional enrichment analysis results show that differentially expressed genes are mainly concentrated in biological processes, such as immune response and neurogenesis. The cellular components involved mainly include axons, postsynaptic membranes, etc, and their molecular functions mainly involve proteoglycan binding, collagen binding, etc. Kyoto Encyclopedia of Genes and Genomes analysis shows that the intersection genes are mainly in signaling pathways related to the immune system, inflammatory response, and nervous system, such as Th17 cell differentiation, Toll-like receptor signaling pathway, tumor necrosis factor signaling pathway, NF-κB signaling pathway, axon guidance, PI3K-Akt signaling pathway, HIF-1 signaling pathway, gap junction, etc. Jak-STAT signaling pathway, mTOR signaling pathway, and related hub genes regulate immune cells and inflammatory factors and play an important role in the development and progression of CP.

Comprehensive whole-genome sequence analyses provide insights into the genomic architecture of cerebral palsy.

We performed whole-genome sequencing (WGS) in 327 children with cerebral palsy (CP) and their biological parents. We classified 37 of 327 (11.3%) children as having pathogenic/likely pathogenic (P/LP) variants and 58 of 327 (17.7%) as having variants of uncertain significance. Multiple classes of P/LP variants included single-nucleotide variants (SNVs)/indels (6.7%), copy number variations (3.4%) and mitochondrial mutations (1.5%). The COL4A1 gene had the most P/LP SNVs. We also analyzed two pediatric control cohorts (n = 203 trios and n = 89 sib-pair families) to provide a baseline for de novo mutation rates and genetic burden analyses, the latter of which demonstrated associations between de novo deleterious variants and genes related to the nervous system. An enrichment analysis revealed previously undescribed plausible candidate CP genes (SMOC1, KDM5B, BCL11A and CYP51A1). A multifactorial CP risk profile and substantial presence of P/LP variants combine to support WGS in the diagnostic work-up across all CP and related phenotypes.

Genetic variants in the HLA region contribute to the risk of cerebral palsy.

Cerebral palsy (CP) is the most common physical disability in childhood, and genetic factors play an important role in its pathogenesis. However, the genetic contributions remain incompletely elucidated. Here, we conducted a two-stage association study between 1090 CP cases and 1100 healthy controls after whole exome sequencing. The human leukocyte antigen (HLA) allelic predispositions were further analyzed in overall CP and subgroups using multivariate logistic regression. We found a strong signal in the HLA region on chromosome 6, where rs3131787 harbored the most significant association with CP (P = 2.05 × 10-14, OR = 2.22). In comparison to controls, the carrier frequencies of HLA-B*13:02 were significantly higher in children with CP (9.82 % in control vs 19.27 % in CP, P = 1.03 × 10-4, OR = 2.17). Furthermore, the effect of HLA-B*13:02 on increasing the risk of CP mainly existed in cryptogenic CP without exposure to premature birth, low birth weight, birth asphyxia, or periventricular leukomalacia. This study indicated a strong association of HLA variants with CP, which implied that immune dysregulation resulting from immunogenetic variants might underlie the pathogenesis of CP. Our findings provide genetic evidence that an immunomodulator may serve as a promising therapeutic intervention for patients with CP by reinstating the neuroinflammation hemostasis.

Etiology and Ontogeny of Cerebral Palsy: Implications for Practice and Research.

Cerebral palsy (CP) has been recognized as a group of neurologic disorders with varying etiologies and ontogenies. While a percentage of CP cases arises during labor, the expanded use of electronic fetal monitoring (EFM) to include prevention of CP has resulted in decades of vastly increased interventions that have not significantly reduced the incidence of CP for infants born at term in the USA. Litigation alleging that poor obstetrical practice caused CP in most of these affected children has led to contentious arguments regarding the actual etiologies of this condition and often resulted in substantial monetary awards for plaintiffs. Recent advances in genetic testing using whole exome sequencing have revealed that at least one-third of CP cases in term infants are genetic in origin and therefore not labor-related. Here, we will present and discuss previous attempts to sort out contributing etiologies and ontogenies of CP, and how these newer diagnostic techniques are rapidly improving our ability to better detect and understand such cases. In light of these developments, we present our vision for an overarching spectrum for proper categorization of CP cases into that the following groups: (1) those begun at conception from genetic causes (nonpreventable); (2) those stemming from adverse antenatal/pre-labor events (possibly preventable with heightened antepartum assessment); (3) Those arising from intrapartum events (potentially preventable by earlier interventions); (4) Those occurring shortly after birth (possibly preventable with closer neonatal monitoring); (5) Those that appear later in the postnatal period from non-labor-related causes such as untreated infections or postnatal intracranial hemorrhages.

Gain-of-Function KIDINS220 Variants Disrupt Neuronal Development and Cause Cerebral Palsy.

BACKGROUND: Kinase D-interacting substrate of 220 kDa (KIDINS220) is a multifunctional scaffolding protein essential for neuronal development. It has been implicated in neurological diseases with either autosomal dominant (AD) or autosomal recessive (AR) inheritance patterns. The molecular mechanisms underlying the AR/AD dual nature of KIDINS220 remain elusive, posing challenges to genetic interpretation and clinical interventions. Moreover, increased KIDINS220 exhibited neurotoxicity, but its role in neurodevelopment remains unclear. OBJECTIVE: The aim was to investigate the genotype-phenotype correlations of KIDINS220 and elucidate its pathophysiological role in neuronal development. METHODS: Whole-exome sequencing was performed in a four-generation family with cerebral palsy. CRISPR/Cas9 was used to generate KIDINS220 mutant cell lines. In utero electroporation was employed to investigate the effect of KIDINS220 variants on neurogenesis in vivo. RESULTS: We identified in KIDINS220 a pathogenic nonsense variant (c.4177C > T, p.Q1393*) that associated with AD cerebral palsy. We demonstrated that the nonsense variants located in the terminal exon of KIDINS220 are gain-of-function (GoF) variants, which enable the mRNA to escape nonsense-mediated decay and produce a truncated yet functional KIDINS220 protein. The truncated protein exhibited significant resistance to calpain and consequently accumulated within cells, resulting in the hyperactivation of Rac1 and defects in neuronal development. CONCLUSIONS: Our findings demonstrate that the location of variants within KIDINS220 plays a crucial role in determining inheritance patterns and corresponding clinical outcomes. The proposed interaction between Rac1 and KIDINS220 provides new insights into the pathogenesis of cerebral palsy, implying potential therapeutic perspectives. © 2023 International Parkinson and Movement Disorder Society.

Prevalence, Clinical Features, Neuroimaging, and Genetic Findings in Children With Ataxic Cerebral Palsy in Europe.

BACKGROUND AND OBJECTIVES: To report on prevalence, associated impairments, severity, and neuroimaging findings in children with ataxic cerebral palsy (CP). METHODS: In children coded as having ataxic CP in the Central database of Joint Research Center-Surveillance of Cerebral Palsy in Europe (JRC-SCPE) and born during 1980-2010, birth characteristics, severity profiles including associated impairments, neuroimaging patterns, and the presence of syndromes were analyzed. Definitions were according to validated SCPE guidelines. Prevalence over time was estimated using Poisson regression. RESULTS: In total, 679 children with ataxic CP were identified in 20 European CP registers. The proportion with ataxic CP was 3.8% and varied from 0% to 12.9%. Prevalence over time showed no significant trend. Approximately 70% of children with ataxic CP were able to walk, and 40% had severe intellectual impairment and a high impairment index. Children with ataxic CP were mostly born at term (79%) and with normal birth weight (77%). Neuroimaging patterns revealed normal findings in 29%, brain maldevelopments in 28.5%, miscellaneous findings in 23.5%, and brain injuries in 19%, according to the SCPE classification. Genetic syndromes were described in 9%. DISCUSSION: This register-based multicenter study on children with ataxic CP provides a large sample size for the analysis of prevalence, severity, and origin of this rare CP subtype. Even with strict inclusion and classification criteria, there is variation between registers on how to deal with this subtype, and diagnosis of ataxic CP remains a challenge. Ataxic cerebral palsy differs from other CP subtypes: children with ataxic CP have a disability profile that is more pronounced in terms of cognitive than gross motor dysfunction. They are mostly term born and the origin rarely suggests acquired injuries. In addition to neuroimaging, a comprehensive genetic workup is particularly recommended for children with this CP type.

Limitations of Multigene Next-Generation Sequencing Panel for "Cerebral Palsy" Phenotype and Other Complex Movement Disorders.

In the past couple of decades, literature in pediatric neurology and clinical genetics has identified hundreds of monogenic disorders that can masquerade as infantile cerebral palsy (CP). Accurate and prompt diagnosis in such cases may be challenging due to several reasons. There are commercial multigene CP panels, but their diagnostic yield is often limited compared with exome sequencing because of diverse etiologies that may mimic CP. We report one such case where a patient with spastic hemiplegia underwent a long diagnostic journey before genetic diagnosis was established with exome sequencing and appropriate management was started. TTC19-related mitochondrial complex III deficiency is an ultrarare disorder of energy metabolism that presents with bilateral lesions in the basal ganglia and a degenerative neuropsychiatric phenotype.

Radiological and Genetic Evaluation in Hypotonic Infants.

OBJECTIVE: To investigate the importance and diagnostic yield of genetic and radiological evaluations in children with hypotonia. STUDY DESIGN: Comparative observational study. Place and Duration of the Study: Department of Pediatrics Neurology, Namik Kemal University, Tekirdag, Turkey, between 2019 and 2022. METHODOLOGY: Patients' medical histories, laboratory results, radiological examinations, and genetic tests, if any, were obtained retrospectively from the patients' clinic files. Children with hypotonia detected since the infantile period and who were on regular follow-up were included in the study. Patients who lost the follow-up were excluded. RESULTS: Out of one hundred and seventy patients, 61.8% (n=105) were boys and 38.2% (n=65) were girls. The admission age of the patients ranged from 1 to 121 months; the mean age at presentation was 13.52±17.35 months. Hypotonia was central in 85.3% (n=145), peripheral in 12.4% (n=21), and mixed in 2.3% (n=4). Cerebral palsy was the predominant, non-genetic clinical cause of hypotonia (n=66, 39%). Brain magnetic resonance imaging (MRI) was normal in 48.2% (n=82). The most common MRI abnormality was periventricular leukomalacia in 15.9% (n=27). Sixty-five (38.2%) patients were diagnosed genetically. More than half of the patients with a genetic diagnosis were diagnosed by whole exome sequencing (WES). CONCLUSION: Brain MRI is the first choice for the patients with central hypotonia. Patients who cannot be diagnosed with clinical findings and brain MRI should undergo WES. This is helpful for the long-term prognosis and management. KEY WORDS: Hypotonia, Whole exome sequencing, Magnetic resonance, Spinal muscular atrophy, Cerebral palsy.

De novo TRPM3 missense variant associated with neurodevelopmental delay and manifestations of cerebral palsy.

We identified a de novo heterozygous transient receptor potential cation channel subfamily M (melastatin) member 3 (TRPM3) missense variant, p.(Asn1126Asp), in a patient with developmental delay and manifestations of cerebral palsy (CP) using phenotype-driven prioritization analysis of whole-genome sequencing data with Exomiser. The variant is localized in the functionally important ion transport domain of the TRPM3 protein and predicted to impact the protein structure. Our report adds TRPM3 to the list of Mendelian disease-associated genes that can be associated with CP and provides further evidence for the pathogenicity of the variant p.(Asn1126Asp).

Redefining cerebral palsies as a diverse group of neurodevelopmental disorders with genetic aetiology.

Cerebral palsy is a clinical descriptor covering a diverse group of permanent, non-degenerative disorders of motor function. Around one-third of cases have now been shown to have an underlying genetic aetiology, with the genetic landscape overlapping with those of neurodevelopmental disorders including intellectual disability, epilepsy, speech and language disorders and autism. Here we review the current state of genomic testing in cerebral palsy, highlighting the benefits for personalized medicine and the imperative to consider aetiology during clinical diagnosis. With earlier clinical diagnosis now possible, we emphasize the opportunity for comprehensive and early genomic testing as a crucial component of the routine diagnostic work-up in people with cerebral palsy.

Dystonic Cerebral Palsy Phenotype Due to GNAO1 Variant Responsive to Levodopa.

Background: Cerebral palsy (CP) should not be considered a diagnosis, but rather a syndrome related to several etiologies, including, but not limited to, neurological sequelae of a perinatal brain injury. Case report: 24-years-old man with dystonia and delayed motor and cognitive development had been previously diagnosed with CP. Molecular genetic testing identified a heterozygosity variant in GNAO 1 gene. A therapeutic trial with levodopa was started, with improvement of dystonia. Discussion: GNAO1 gene variant disorders share similarities with other causes of CP syndrome, and thus investigation of this variant should be included in instances of CP syndrome without a clear history of previous perinatal brain injury. GNAO1 dystonic phenotype (DYT-GNAO1) should be considered as dopa-responsive dystonia in some cases.

Scalp acupuncture Yikang therapy on Baihui (GV20), Sishencong (EX-HN1), Zhisanzhen, Niesanzhen improves neurobehavior in young rats with cerebral palsy through Notch signaling pathway.

OBJECTIVE: To investigate the efficacy of scalp acupuncture Yikang therapy on Baihui (GV20), Sishencong (EX-HN1), Zhisanzhen, Niesanzhen, on neurobehavior in young rats with cerebral palsy based on Notch signaling pathway. METHODS: Thirty 7-day-old rats were randomly divided into sham, model and acupuncture, 10 rats in each group. The cerebral palsy model was established by the accepted modeling method, the acupuncture group selected "Baihui (GV20)", "Sishencong (EX-HN1)", "Zhisanzhen" and "Niesanzhen" for intervention 24 h after the model was made. The body masses were recorded before and after the treatment, respectively. After the intervention, the rats were subjected to suspension experiment, slope experiment, tactile stimulation experiment and Morris water maze experiment. After the end of the experiment, the morphological changes of hippocampal histology were observed by hematoxylin-eosin (HE) staining under light microscope, and the expression of Notch1, Notch3 and Hes5 were detected by Western blot and quantitative real-time polymerase chain reaction (PCR). RESULTS: The changes in body mass of the rats in each group were different; in behavioral experiments, compared with the sham, the suspension time of the model was shortened, the slope experiment, tactile stimulation experiment, and escape latency time were prolonged, and the number of platform crossing was reduced in the model, compared with the model, the suspension time of the acupuncture was prolonged, the slope experiment, tactile stimulation experiment, and escape latency time were shortened, and the number of platform crossing times was increased; HE staining showed severe hippocampal damage in the model and reduced hippocampal damage in the acupuncture. Western Blot and real-time fluorescence quantitative PCR showed that the expression of Notch1, Notch3 and Hes5 were increased in the model and the expression of Notch1, Notch3, Hes5 in acupuncture were decreased. CONCLUSIONS: Scalp acupuncture Yikang therapy may improve neurobehavior and reduce brain injury in rats with cerebral palsy by downregulating the expression of Notch1, Notch3, and Hes5.

Predictors of whole exome sequencing in dystonic cerebral palsy and cerebral palsy-like disorders.

INTRODUCTION: Cerebral palsy (CP) is a group of permanent disorders attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. Cerebral palsy-like (CP-like) disorders may clinically resemble CP but do not fulfill CP criteria and have often a progressive course and/or neurodevelopmental regression. To assess which patients with dystonic CP and dystonic CP-like disorder should undergo Whole Exome Sequencing (WES), we compared the rate of likely causative variants in individuals regarding their clinical picture, co-morbidities, and environmental risk factors. METHOD: Individuals with early onset neurodevelopmental disorder (ND) manifesting with dystonia as a core feature were divided into CP or CP-like cohorts based on their clinical picture and disease course. Detailed clinical picture, co-morbidities, and environmental risk factors including prematurity, asphyxia, SIRS, IRDS, and cerebral bleeding were evaluated. RESULTS: A total of 122 patients were included and divided into the CP group with 70 subjects (30 males; mean age 18y5m±16y6m, mean GMFCS score 3.3 ± 1.4), and the CP-like group with 52 subjects (29 males; mean age 17y7m±1y,6 m, mean GMFCS score 2,6 ± 1,5). The WES-based diagnosis was present in 19 (27.1%) CP patients and 30 CP-like patients (57.7%) with genetic conditions overlap in both groups. We found significant differences in diagnostic rate in CP individuals with vs. without risk factors (13.9% vs. 43.3%); Fisher's exact p = 0.0065. We did not observe the same tendency in CP-like (45.5% vs 58.5%); Fisher's exact p = 0.5. CONCLUSION: WES is a useful diagnostic method for patients with dystonic ND, regardless of their presentation as a CP or CP-like phenotype.

MECP2 duplication syndrome initially misdiagnosed as cerebral palsy: a case report.

Mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene were first described as a cause of Rett syndrome. MECP2 duplication can cause intellectual disability, developmental delay, severe feeding difficulties, and recurrent infections. Here, we report a Korean family with MECP2 duplication syndrome, which was previously misdiagnosed as cerebral palsy. A man in his early 30 s visited our clinic with intellectual disability, speech impairment, epilepsy, and progressive spasticity. He had been previously misdiagnosed with cerebral palsy, and had received orthopedic surgeries such as musculotendinous lengthening and derotational osteotomy. After the surgeries, he received comprehensive rehabilitation. Upon carefully checking his family history, we noted that his younger brother had similar symptoms. Next-generation sequencing revealed whole exon duplication in MECP2 in both the patient and his brother; their mother also had this genetic mutation but was asymptomatic. Early diagnosis is essential for improving the success of MECP2 duplication syndrome treatment. Individuals with MECP2 duplication syndrome should be referred to specialists to manage multidisciplinary symptoms and to regularly check for complications that are common in this syndrome.