Background Lamb-Shaffer syndrome (LAMSHF, OMIM: 616803) is a rare neurodevelopmental disorder characterized by global developmental delay, intellectual disability, poor expressive speech, which is attributed to haploinsufficiency by heterozygous variants of SOX5 gene (SRY-Box Transcription Factor 5, HGNC: 11201) on chromosome 12p12. A total of 113 cases have been reported in the world, however, only 3 cases have been reported.in China. Here, we aimed to report novel variants of SOX5 gene and provide examples for clinical diagnosis by reporting the clinical phenotype of a series of Chinese patients with LAMSHF. Methods This study retrospectively collected the information of families of LAMSHF patients in China. Whole Exome Sequencing (WES) were performed to confirm the diagnosis of 4 children with unexplained developmental delay or epilepsy. A minigene splicing assay was used to verify whether the splice variant affected splicing. Meanwhile, a literature review was conducted to analyze the clinical and genetic characteristics of patients with LAMSHF. Results Three of the LAMSHF patients had a de novo heterozygous mutation in the SOX5 gene respectively, c.290delC (p.Pro97fs*30), chr12:23686019_24048958del, c.1772-1C > A, and the remaining one had a mutation inherited from his father, c.1411C > T (p.Arg471*). The main clinical manifestations of these children were presented with global developmental delays, and one of them also had seizures. And the results of the minigene experiment indicated that the splice variant, c.1772-1C > A, transcribed a novel mRNA product which leaded to the formation of a truncated protein. Conclusions Through a comprehensive review and analysis of existing literature and this study showed intellectual disability, speech delay and facial dysmorphisms were common clinical manifestation, while the seizures and EEG abnormalities were rare (21/95, 22.16%). Notably, we represent the largest sample size of LAMSHF in Asia that encompasses previously unreported SOX5 gene mutation, and a minigene testing have been conducted to validate the pathogenicity of the c.1772-1C > A splice variant. The research further expands the phenotype and genotype of LAMSHF while offers novel insights for potential pathogenicity of genes locus.

Background Neurodevelopmental disorder with spasticity, cataracts, and cerebellar hypoplasia (NEDSCAC), induced by MED27 gene, is an autosomal recessive rare disorder characterized by widespread developmental delay with varying degrees of intellectual impairment. Other symptoms include limb spasticity, cataracts, and cerebellar hypoplasia. So far there have been limited reports on NEDSCAC. Methods In this study, we conducted genetic testing on a child presenting with developmental delay as the primary clinical feature. The genetic test results indicated the presence of novel homozygous missense variants c.74G>A, p.(Arg25His) in the MED27 gene. In vitro functional validation experiments, including plasmid construction and cell transfection, Western blotting, and molecular dynamics structural modeling, were performed on the MED27 Arg25His variant. Results The results demonstrated a significant reduction in protein expression of MED27 Arg25His and indicated may weaken the interaction force between the MED27 subunit and MED14 subunit. Conclusions This study expands our understanding of MED27 gene variants and their associated clinical phenotypes. Additionally, it contributes to the investigation of the potential pathogenesis of NEDSCAC caused by MED27 gene variants.

BackgroundIntellectual disability, X-linked, syndromic, Christianson type (MRXSCH, OMIM: 300243)-known as Christianson syndrome (CS)-is characterized by microcephaly, epilepsy, ataxia, and absence of verbal language ability. CS is attributed to mutations in the solute carrier family 9 member A6 gene (SLC9A6). Materials and methodsThis study reports the case of a boy 1 year and 3 months of age who was diagnosed with CS in our department. Genetic etiology was determined by whole-exome sequencing, and a minigene splicing assay was used to verify whether the mutation affected splicing. A literature review of CS cases was conducted and the clinical and genetic features were summarized. ResultsThe main clinical manifestations of CS include seizures, developmental regression, and exceptional facial features. Whole-exome sequencing revealed a de novo splice variant in intron 11 (c.1366 + 1G > C) of SLC9A6. The mutation produced two abnormal mRNA products (verified by a minigene splicing assay), resulting in the formation of truncated protein. A total of 95 CS cases were identified in the literature, with various symptoms, such as delayed intellectual development (95/95, 100.00%), epilepsy (87/88, 98.86%), and absent verbal language (75/83, 90.36%). At least 50 pathogenic variants of SLC9A6 have been identified, with the highest frequency observed in exon 12. ConclusionOur patient is the first case with the c.1366 + 1G > C variant of SLC9A6 in CS. The summary of known cases can serve as a reference for analyzing the mutation spectrum and pathogenesis of CS.

ObjectiveThis study aims to describe the characteristics of the brain network attributes in children diagnosed with Infantile Epileptic Spasms Syndrome (IESS) and to determine the influence exerted by adrenocorticotrophic hormone (ACTH) or methylprednisolone (MP) on network attributes.MethodsIn this retrospective cohort study, we recruited 19 infants diagnosed with IESS and 10 healthy subjects as the control from the Pediatric Neurology Department at the Third Affiliated Hospital of Zhengzhou University between October 2019 and December 2020. The first thirty-minute processed electroencephalograms (EEGs) were clipped and filtered into EEG frequency bands (2 s each). A comparative assessment was conducted between the IESS group and the controls as well as the pre- and post-treatment in the IESS group. Mutual information values for each EEG channel were collected and compared including characteristic path length (CPL), node degree (ND), clustering coefficient (CC), and betweenness centrality (BC), based on graph theory.ResultsComparing the control group, in the IESS group, there was an increase in CPL of the Delta band, and a decrease in ND and CC of the Delta band during the waking period, contrary to those during the sleeping period (P < 0.05), a decreased in CPL of the fast waves and an increase in ND and CC (P < 0.05) in the sleep-wake cycle, and a decrease in ND and CC of the Theta band in the waking phase. Post-treatment compared with the pre-treatment, during the waking ictal phase, there was a noted decrease in CPL in the Delta band and fast waves, while an increase was observed in ND and CC (P < 0.05).ConclusionsThe Delta band and fast waves are crucial components of the network attributes in IESS.SignificanceThis investigation provides a precise characterization of the brain network in children afflicted with IESS, and lays the groundwork for predicting the prognosis using graph theory.

Objective To analyze the clinical data of 2 cases of CHD2 gene related epilepsy and to investigate their phenotypes and gene mutation types. Methods The clinical data of 2 probands and their families were collected. The peripheral blood of the probands and their parents was extracted for genomic DNA. High-throughput sequencing was used to detect the exons and their intronic regions to define the gene mutation sites, and the pathogenic variations were verified by PCR-Sanger sequencing. The conservativeness of gene variation sites in the probands was analyzed by UCSC softwares, and the pathogenicity of variation sites was analyzed by using the Varseak and Mutation Taster softwares. Results Convulsions developed in two patients at the age of about 3 years old. Proband 1 was manifested with tonic-clonic seizures, which was controlled by levetiracetam and sodium valproate treatment after being diagnosed as epilepsy and autism spectrum disorder. This proband was detected heterozygous mutation of CHD2 gene c.2877-1＿2877delGCinsAA, which was a splicing receptor mutation. The corresponding base（C） at C.2877-1 and the corresponding amino acid（asparagine） at c.2877 were highly conserved in 13 species. Parental verification and query of human gene database indicated that it was a de novo mutation. The analysis results of Varseak predicted that the mutation would lead to changes in protein sequence and structure, and was possibly pathogenic according to the ACMG classification. Proband 2 was diagnosed with Lennox-Gastaut syndrome, with multiple seizure patterns combined with severe developmental delay. Seizures were controlled after treatment with levetiracetam, while other drugs had poor efficacy. There was a heterozygous mutation of CHD2 gene c.361C＞T（p.Arg121Ter）,which was a nonsense mutation.The 121amino acid（arginine）corresponding to the c.361C＞T mutation was highly conserved in 13species.The mutation was verified as a de novo mutation in the pedigree,Mutation Taster software analysis indicated that it was suspected to be pathogenic mutation,and it was pathogenic according to the ACMG classification.Conclusion The children with epilepsy accompanied by developmental delay and autism spectrum disorder should consider the CHD2 gene mutation,and genetic test contributes to the early diagnosis.

Objective:To explore the clinical manifestations and genetic characteristics of Wolf-Hirschhorn syndrome (WHS) to improve the ability of diagnosis and differential diagnosis of the disease.Methods:The clinical features and auxiliary examinations and treatment of a proband with WHS caused by microdeletion of 4p16.3 segment who admitted to the Third Affiliated Hospital of Zhengzhou University in December 2021 were recorded, and whole exome sequencing (WES) of the family was performed. The prognosis was followed up.Results:The female proband, 11 months old, presented with convulsions at the age of 8 months, with the characteristics of heat sensitivity and cluster seizures, and her identical twin sister had a similar medical history. Physical examination found malnutrition, retarded development, special face, prominent forehead, wide nasal bridge, small jaw, precordial murmur and grade 3/6 murmur in the whole period, hyperactivity of P2, and low limb muscle tone. The whole exon and copy number variation (CNV) test of the family revealed that the proband had a 1.99 Mb heterozygous deletion in the chromosome 4p16.3 segment, including WHSC1 (NSD2), WHSC2 (NEFLA) and other genes. Copy number variation sequencing (CNV-Seq) of the proband and her sister showed 1.97 and 1.92 Mb heterozygous deletion of chromosome 4p16.3, respectively. Genealogical analysis by quantitative polymerase chain reaction revealed that the CNV was de novo, and it was determined to be a pathogenic variant according to the American College of Medical Genetics and Genomics guidelines. The proband took sodium valproate orally, and her sister took oral sodium valproate, zonisamide, and levetiracetam successively, and at the same time they received family rehabilitation training. The age at the last follow-up was 1 year and 8 months. Neither of them had convulsions again in the past 3 months, but the developmental delay was obvious. Conclusion:WHS patients may present with growth retardation, epilepsy, Greek warrior helmet-like special face, and congenital heart disease, and may have microdeletions in the chromosome 4p16.3 segment.

Abstract Objective Defects in RARS2 cause cerebellopontine hypoplasia type 6 (pontocerebellar hypoplasia type 6, PCH6, OMIM: #611523), a rare autosomal recessive inherited mitochondrial disease. Here, we report two male patients and their respective family histories. Methods We describe the clinical presentation and magnetic resonance imaging (MRI) findings of these patients. Whole‐exome sequencing was used to identify the genetic mutations. Results One patient showed hypoglycemia, high lactic acid levels (fluctuating from 6.7 to 14.1 mmol/L), and frequent seizures after birth, with progressive atrophy of the cerebrum, cerebellum, and pons. The other patient presented with early infantile developmental and epileptic encephalopathies (EIDEEs) with an initial developmental delay followed by infantile epileptic spasm syndrome (IESS) at 5 months old, with no imaging changes. Whole‐exome sequencing identified compound heterozygous RARS2 variants c.25A>G (p.I9V) with c.1261C>T (p.Q421*) and c.1A>G (p.M1V) with c.122A>G (p.D41G) in these two patients. Of these loci, c.1261C>T and c.122A>G have not been previously reported. Significance Our findings have expanded the RARS2 gene variant spectrum and present EIDEEs and IESS as phenotypes which deepened the association between PCH6 and RARS2. Plain Language Summary Defects in RARS2 cause cerebellopontine hypoplasia type 6, a rare autosomal recessive inherited mitochondrial disease. Two patients with RARS2 variants were reported in this article. One patient showed hypoglycemia, high lactic acid levels, and frequent seizures after birth, with progressive atrophy of the cerebrum, cerebellum, and Page 3 of 21 Epilepsia OpenFor Review Only pons. The other patient presented with an initial developmental delay followed by refractory epilepsy at 5 months old, with no imaging changes. Our findings deepened the association between PCH6 and RARS2.