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PubMed2024

A novel variant in the SPTB gene underlying hereditary spherocytosis and a literature review of previous variants.

BACKGROUND: Hereditary spherocytosis (HS, MIM#612641) is one of the most common hereditary hemolytic disorders. This study aimed to confirm a novel variant's pathogenicity and reveal a patient's genetic etiology. METHODS: The clinical data of a patient with HS who underwent genetic sequencing at the Children's Hospital of Chongqing Medical University were reviewed retrospectively. In silico prediction and in vitro minigene splicing reporter system were then conducted on the detected variant to analyze its intramolecular impact. A summary of the literature related to HS due to SPTB gene variants was also presented. RESULTS: A novel variant (c.301-2 A > G) in the SPTB gene (NM_001024858.4) was identified in the proband. Using Sanger sequencing, we conclusively confirmed that the inheritance of the variant could not be traced to the biological parents. The in vitro minigene assay revealed three different transcripts derived from the c.301-2 A > G variant: r.301_474del, r.301_306delCCAAAG, and r.301-1_301-57ins. Through a literature review, patients with HS who had been genotypically validated were summarized and the SPTB gene variant profile was mapped. CONCLUSION: We identified a splicing variant of the SPTB gene, thus confirming its aberrant translation. The novel variant was the probable genetic etiology of the proband with HS. Our findings expanded the variant spectrum of the SPTB gene, thus improving the understanding of the associated hereditary hemolytic disorders from a clinical and molecular perspective and contributing to the foundation of genetic counseling and diagnosis.

Humans↗
PubMed1977

Adenylate cyclase permanently uncoupled from hormone receptors in a novel variant of S49 mouse lymphoma cells.

A novel variant of the S49 mouse lymphoma has been selected from wild-type cells by growth in medium containing the beta-adrenergic agonist terbutaline and inhibitors of cyclic nucleotide phosphodiesterase. In contrast to the situation in the wild-type clone, synthesis of adenosine 3':5'-monophosphate (cyclic AMP) is not stimulated by beta-adrenergic agonists or by prostaglandin E1 either in intact variant cells or in membrane preparations of such clones. However, basal and NaF-stimulated activities of adenylate cyclase [ATP pyrophosphate-lyase (cyclizine), EC 4.6.1.1] are normal, enzyme activity is stimulated by guanyl-5'-yl imidodiphosphate [Gpp(NH)p], and intact cells accumulate cyclic AMP when exposed to cholera toxin. Furthermore, variant cell membranes possess ligand-binding activity consistent with the conclusion that a normal or an excessive number of beta-adrenergic receptors is present. Thus, interaction between the hormone-binding and the catalytic moieties of the adenylate cyclase system is lost. This variant phenotype, designated as uncoupled (UNC), has been stable for more than 100 generations without exposure to the drugs used for selection. Such cells should be useful for the elucidation of methanisms of transmission of information from hormone receptors to adenylate cyclase.

Adenylyl Cyclases↗
PubMed2025

Molecular characterization, clinical phenotype, and neurological outcome of twelve Palestinian children with beta-ketothiolase deficiency: report of two novel variants in the ACAT1 gene.

BACKGROUND: Beta-ketothiolase deficiency (mitochondrial acetoacetyl-CoA thiolase, T2) deficiency (OMIM #203750, *607809) is an autosomal recessive disorder of isoleucine catabolism and ketone body utilization. It is caused by mutations in the ACAT1 gene and characterized by intermittent ketoacidosis episodes triggered by ketogenic stresses, with no clinical symptoms between the episodes. Neurological complications, particularly extrapyramidal signs may occur as sequelae of the ketoacidosis episodes but may also occur without or before any apparent metabolic crisis. T2 deficiency is characterized by the accumulation of isoleucine metabolites, 2methylacetoacetate, 2-methyl-3-hydroxybutyrate, and tiglylglycine, detected in urine organic acids and blood acylcarnitines with or without hypoglycemia. METHODS: This study presents data from twelve patients with T2 deficiency, diagnosed between 7 months and 22 months of age at two tertiary care centers in Palestine. The clinical, biochemical, molecular genetic data, and neurological outcomes are reviewed. RESULTS: We report on twelve patients (6 females and 6 males) from eight families in four different regions of the West Bank and Gaza Strip. All patients were offspring of consanguineous marriages. Ketoacidotic episodes were the predominant manifestations in all patients, and each episode was triggered by either acute gastroenteritis or upper respiratory infections. One patient initially presented with hypotonia and psychomotor delay, later developing a ketoacidotic episode a few months afterward. The characteristic laboratory finding in all patients was the increased urinary excretion of 2-methyl-3-hydroxybutyrate and tiglylglycine. Ten of the twelve patients had favorable outcomes, while two unfortunately passed away at the time of the study. Molecular genetic analysis of the ACAT1 gene was conducted on nine patients from six families, revealing four different variants, two of which were novel. Additionally, a founder mutation was identified in six patients from three families. CONCLUSIONS: The study underscores the critical role of genetic research in unraveling the complexities of beta-ketothiolase deficiency and related disorders. By identifying haplotype blocks, founder mutations, and novel pathogenic variants, researchers can significantly improve diagnostic precision, enhance genetic counseling, and lay the groundwork for developing targeted therapies. We identified two novel variants and a founder mutation, thereby broadening the genetic spectrum of this rare disease.

Humans↗
PubMed2026

Whole exome sequencing identifies three novel variants and establishes the molecular diagnosis of ATP6V0A4-related distal renal tubular acidosis in a lebanese infant.

BACKGROUND: Distal renal tubular acidosis (dRTA) is a rare inherited disorder characterized by impaired urinary acidification, leading to metabolic acidosis, hypokalemia, nephrocalcinosis, and growth impairment. Pathogenic variants in ATP6V0A4 are among the most common genetic causes of autosomal recessive dRTA. METHODS AND RESULTS: We report a Lebanese infant presenting with failure to thrive, recurrent vomiting, severe hyperchloremic metabolic acidosis, hypokalemia, and bilateral nephrocalcinosis, in whom whole-exome sequencing (WES) was performed to establish the molecular diagnosis and perform a comprehensive genomic evaluation. WES identified three novel variants, including a novel homozygous likely pathogenic ATP6V0A4 variant, consistent with the patient's phenotype. Two additional novel variants in TTN and CEP290 were also detected. Family segregation analysis confirmed the inheritance pattern of all three variants and refined the interpretation of the additional genomic findings. The patient showed sustained clinical and biochemical improvement to alkali therapy, with normalization of biochemical abnormalities and improvement in growth during follow-up. CONCLUSIONS: This report expands the molecular spectrum of ATP6V0A4-related dRTA and illustrates the clinical utility of comprehensive WES combined with segregation analysis for accurate molecular diagnosis, variant interpretation, genetic counseling, and the evaluation of additional genomic findings in rare inherited disorders.

Humans↗
PubMed2025

Whole-genome sequencing, as a powerful diagnostic tool in hearing loss, reveals novel variants in PTPRQ missed by whole-exome sequencing.

BACKGROUND/OBJECTIVES: Hearing loss (HL) is one of the most common congenital disorders, affecting 1-2 in 1,000 newborns. Modern genetic diagnostics using large gene panels and/or whole exome analysis (WES) can identify disease-causing mutations in 25-50 % of patients, with higher solve rates in individuals with earlier onset. RESULTS: Here, we used whole-genome sequencing (WGS) to reanalyze 14 index patients/families who remained without genetic diagnosis by WES. We were able to identify the genetic cause of HL in 6 families (43 %). Two families were diagnosed with DFNB84A caused by compound heterozygous recessive mutations in PTPRQ. Three of the four underlying variants, including a structural variant, a deep intronic variant, and a splice variant, escaped detection by WES. Minigene assays confirmed the pathogenicity of the intronic and the splice variants. In addition, we used protein 3D structure prediction and rigid ligand docking to study the pathogenicity of variants that escape nonsense-mediated decay. CONCLUSION: In our study, we present four novel variants in PTPRQ, three of which were detected only by WGS. To our knowledge, we report here the first pathogenic deep intronic PTPRQ variant causing HL. Our results suggest that the mutational spectrum of PTPRQ is not well covered by standard WES and that PTPRQ-associated hearing loss may be more frequent than previously thought. WGS provides an additional layer of information in the diagnostics of HL.

Humans↗
PubMed2026

[Analysis of a Chinese pedigree affected with Townes-Brocks syndrome due to a novel variant of SALL1 gene and a literature review].

OBJECTIVE: To analyze a novel exonic variant of the SALL1 gene and its impact on the binding site of SALL protein. METHODS: Clinical data of three children diagnosed with Townes-Brocks syndrome and their family members who had presented at the First Affiliated Hospital of Shandong First Medical University in April 2022 were retrospectively collected. The pathogenic variant was identified through whole-genome sequencing (WGS) and validated by Sanger sequencing. Protein structural prediction was performed using AlphaFold and PyMOL software to construct three-dimensional models of the wild-type and mutant proteins. Additionally, previously reported cases were systematically reviewed. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2023-386). RESULTS: The proband was one of triplet sisters born at 34+4 gestational weeks. All three cases had presented with anal atresia and rectovaginal fistula, and case 3 also had toe malformation of left foot. WGS revealed a novel heterozygous c.757C>T (p.Gln253*) variant in the SALL1 gene, which was predicted to be pathogenic. Sanger sequencing confirmed co-segregation of the variant with the disease within the family. Protein structural modeling demonstrated that the variant has introduced a premature stop codon at position 253, resulting in a truncated protein. CONCLUSION: Above finding has enriched the mutation spectrum of the SALL1 gene in association with Townes-Brocks syndrome, which also represented a rare case of anal atresia in triplets, and provided a basis for molecular diagnosis, genetic counseling, and further research.

Humans↗
PubMed2024

A novel variant of biallelic MME gene associated with autosomal recessive late-onset distal hereditary motor neuropathy in Chinese families.

Distal hereditary motor neuropathies (dHMN) are a group of heterogeneous diseases and previous studies have reported that the compound heterozygous recessive MME variants cause dHMN. Our study found a novel homozygous MME variant and a reported compound heterozygous MME variant in two Chinese families, respectively. Next-generation sequencing and nerve conduction studies were performed for two probands. The probands in two families presented with the muscle weakness and wasting of both lower limbs and carried a c.2122 A > T (p.K708*) and c.1342 C > T&c.2071_2072delinsTT (p.R448*&p.A691L) variant, respectively. Prominently axonal impairment of motor nerves and slight involvement of sensory nerves were observed in nerve conduction study. Our study reported a "novel" nonsense mutation and a missense variant of autosomal recessive late-onset dHMN and reviewed reported MME variants associated with dHMN phenotype.

Adult↗
PubMed2026

A novel variant combination in COASY associates with severe prenatal onset PCH12: expanding the clinical and genetic spectrum.

Pontocerebellar hypoplasia type 12 (PCH12) is an ultra-rare, perinatal lethal, neurodegenerative disorder with microcephaly and arthrogryposis. Previous reports have associated PCH12 with complete loss-of-function variants in COASY identified in 14 fetuses and newborns from eight unrelated families. In contrast, COASY partial loss-of-function variants have been linked to COASY protein-associated neurodegeneration (CoPAN), a subtype of neurodegeneration with brain iron accumulation (NBIA). Emerging evidence suggests that COASY-related disorders may represent a phenotypic continuum between PCH12 and CoPAN. Using exome sequencing, we identified a previously reported missense variant (c.641C>T, p.Ala214Val) as well as a previously unreported rare nonsense variant (c.1015C>T, p.Arg339*) in a compound heterozygous state in the COASY gene in a patient presenting with clinical features consistent with PCH12. The p.Ala214Val variant has only been described in combination with another missense variant (p.Arg499Cys) in two siblings with CoPAN. The presence of p.Ala214Val in trans with the truncating p.Arg339* variant in this patient is associated with a severe perinatal lethal phenotype resembling PCH12. This case broadens the reported genetic and phenotypic spectrum of COASY-associated disorders and highlights the importance of continued genotype-phenotype correlation investigation.

Humans↗
PubMed2019

Discovering human transcription factor physical interactions with genetic variants, novel DNA motifs, and repetitive elements using enhanced yeast one-hybrid assays.

Identifying transcription factor (TF) binding to noncoding variants, uncharacterized DNA motifs, and repetitive genomic elements has been technically and computationally challenging. Current experimental methods, such as chromatin immunoprecipitation, generally test one TF at a time, and computational motif algorithms often lead to false-positive and -negative predictions. To address these limitations, we developed an experimental approach based on enhanced yeast one-hybrid assays. The first variation of this approach interrogates the binding of >1000 human TFs to repetitive DNA elements, while the second evaluates TF binding to single nucleotide variants, short insertions and deletions (indels), and novel DNA motifs. Using this approach, we detected the binding of 75 TFs, including several nuclear hormone receptors and ETS factors, to the highly repetitive Alu elements. Further, we identified cancer-associated changes in TF binding, including gain of interactions involving ETS TFs and loss of interactions involving KLF TFs to different mutations in the TERT promoter, and gain of a MYB interaction with an 18-bp indel in the TAL1 superenhancer. Additionally, we identified TFs that bind to three uncharacterized DNA motifs identified in DNase footprinting assays. We anticipate that these enhanced yeast one-hybrid approaches will expand our capabilities to study genetic variation and undercharacterized genomic regions.

Algorithms↗
PubMed2024

Effect of the OPHN1 novel variant c.1025+1 G>A on RNA splicing: insights from a minigene assay.

This research analyzes the clinical data, whole-exome sequencing results, and in vitro minigene functional experiments of a child with developmental delay and intellectual disability. The male patient, aged 4, began experiencing epileptic seizures at 3 months post-birth and has shown developmental delay. Rehabilitation training was administered between the ages of one and two. There were no other significant family medical histories. Through comprehensive family exome genetic testing, a hemizygous variant in the 11th exon of the OPHN1 gene was identified in the affected child: c.1025 + 1G > A. Family segregation analysis confirmed the presence of this variant in the patient's mother, which had not been previously reported. According to the ACMG guidelines, this variant was classified as a likely pathogenic variant. In response to this variant, an in vitro minigene functional experiment was designed and conducted, confirming that the mutation affects the normal splicing of the gene's mRNA, resulting in a 56 bp retention on the left side of Intron 11. It was confirmed that OPHN1: c.1025 + 1G > A is the pathogenic cause of X-linked intellectual disabilities in the child, with clinical phenotypes including developmental delay and seizures.

Humans↗
PubMed2026

Biallelic EZH1 Nonsense Novel Variant in Two Siblings with Neurodevelopmental Disorder and Central Precocious Puberty: A Case Report from a Consanguineous Saudi Family.

Neurodevelopmental disorders (NDDs) are a group of conditions that impair the development and function of the central nervous system. Recently, variants in the EZH1 gene have been associated with neurodevelopmental disorders. Here, using whole-exome sequencing coupled with confirmatory Sanger sequencing, we identified a homozygous nonsense variant in EZH1 in two affected siblings. Both parents were heterozygous carriers of the variant. The variant is predicted to result in a 44-amino acid C-terminal truncation within the catalytic SET domain, leading to loss of protein function. RT-qPCR analysis revealed significantly reduced EZH1 mRNA expression in patient-derived peripheral blood cells. The index patient (female) also exhibited elevated gamma-glutamyl transferase (GGT) levels and hypoalbuminemia, whereas the affected male presented with central precocious puberty. This study further expands the clinical, genetic, and molecular spectrum of EZH1-associated neurodevelopmental disorders by demonstrating that reduced EZH1 expression is consistent with a loss-of-function disease mechanism.

Child↗
PubMed2026

Expanding the genetic landscape of SLC4A1-linked hereditary spherocytosis: discovery of a novel TM9 variant using high-resolution genomic profiling analysis.

INTRODUCTION: Hereditary spherocytosis (HS) is the most common inherited red cell membranopathy caused by defects in erythrocyte membrane and cytoskeletal proteins, including ankyrin, spectrin, band 3, and protein 4.2. Among these, mutations in SLC4A1, which encodes the erythrocyte anion exchanger band 3 (AE1), account for approximately 20-30% of HS cases and it is associated with distal renal tubular acidosis (dRTA), reflecting phenotypic and functional heterogeneity. METHODS: In this study, seven unrelated Indian patients with clinically suspected HS were investigated using detailed hematological, biochemical, and clinical evaluations along with eosin-5'-maleimide (EMA) binding assays. Molecular analysis was performed using targeted next-generation sequencing (t-NGS) covering 81 genes associated with red cell disorders, and the identified SLC4A1 variants were validated by Sanger sequencing. The structural and functional consequences of the variants were assessed through in silico tools including DynaMut, PolyPhen-2, and SIFT. RESULTS: Seven SLC4A1 variants were identified, including six previously reported variants and one novel variant, p.Phe702Ser, detected in heterozygous or compound heterozygous states. These variants were distributed across both cytoplasmic and transmembrane domains of the band 3 protein. Most patients presented with mild to moderate HS characterized by anemia, jaundice, splenomegaly, reticulocytosis, and reduced EMA fluorescence. One patient harboring compound heterozygous variants (p.Arg490His and p.Ala858Asp) exhibited HS associated with dRTA, highlighting the functional diversity of SLC4A1 mutations. The novel p.Phe702Ser variant, located in the transmembrane domain TM9, was predicted to destabilize AE1 structure and potentially impair anion transport. DISCUSSION: Marked intrafamilial phenotypic variability was observed despite identical genotypes. These findings expand the mutational spectrum of SLC4A1-related HS in Indian patients.

SLC4A1↗
PubMed2025

Identification of four novel ACADVL variants in eight Chinese unrelated patients with very long-chain acyl-CoA dehydrogenase deficiency.

BACKGROUND: Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a disorder of mitochondrial fatty acid oxidation with an autosomal recessive manner and is due to the VLCAD enzyme deficiency which is encoded by the ACADVL gene. The purpose of this study was to elucidate the clinical manifestations and analyze the molecular findings of eight Chinese patients with VLCADD. METHODS: We investigated eight Chinese VLCADD patients (three males, five females) from eight unrelated families. Molecular analysis was performed under the application of next-generation sequencing (NGS) in combination with Sanger sequencing validation to confirm the likely pathogenic variants in these patients. RESULTS: Patient 1 (P1) exhibited the most severe clinical features and passed away 3 h after admission on the second day of life. Unfortunately, P2 succumbed to hypoketotic hypoglycemia at 5 months of age. Except for asymptomatic P7, the remaining patients also developed clinical presentations of varying severity at different ages. Molecular data revealed that all affected individuals were compound heterozygotes for ACADVL variants. A total of 14 variants (4 novel and 10 known) were identified and the pathogenicity was evaluated based on the American College of Medical Genetics and Genomics (ACMG) criteria and different in silico prediction tools. CONCLUSIONS: The analysis of genotype-phenotype relationships preliminarily suggests that the compound heterozygous variants identified in these patients are likely the primary cause of VLCADD. Our study expands the mutation spectrum of ACADVL and highlights the significance of genetic analysis in early diagnosis and therapeutic intervention of monogenic hereditary diseases especially those with rapid disease progression.

Female↗
PubMed2026

Disruption of GAD1 protein architecture by a novel missense variant in a consanguineous family with autosomal recessive intellectual disability.

BACKGROUND: Intellectual disability represents a heterogeneous group of neurodevelopmental disorders marked by significant impairments in intellectual functioning and adaptive behavior. Among the various causes, genetic factors play a major role, with autosomal recessive intellectual disability (ARID) constituting a genetically diverse subgroup. ARID is prevalent in consanguineous families and arises from homozygous mutations that disrupt critical genes involved in brain development and function. OBJECTIVE: This study aimed to identify disease-causing genetic variants responsible for ARID in a consanguineous Pakistani family and to evaluate the structural and functional impact of a novel variant identified in GAD1 through protein modeling. METHODS: A consanguineous family affected with intellectual disability was enrolled. Whole-exome sequencing was performed on an affected individual, followed by bioinformatics analysis including alignment to the GRCh38 reference genome, variant calling, and annotation. Variants were filtered based on rarity, predicted functional impact, and autosomal recessive inheritance pattern. Candidate variants were validated and assessed by Sanger sequencing and segregation analysis. Protein modeling was performed to evaluate the structural impact of the identified variant. RESULTS: A novel homozygous missense variant NM_000817:c.1700G>A;p.Arg567Gln in GAD1 was identified. Segregation analysis confirmed co-segregation of the variant with the affected phenotype. Protein modeling suggested that the variant may disrupt GAD1 enzymatic function involved in gamma-aminobutyric acid synthesis. CONCLUSION: This study emphasizes the significance of genetic investigation in familial cases and the crucial role that GAD1 mutations play in neurodevelopmental disorders with intellectual disability. The results advance the knowledge of molecular causes of ARID and broaden the mutational range.

Pakistani↗
PubMed2026

Novel genetic variants identification and immune profiling in ataxia telangiectasia patients.

BACKGROUND: Ataxia telangiectasia (AT) is an autosomal recessive neurodegenerative disease. While heterozygous relatives of AT patients are known to be clinically healthy, a predisposition to various pathologies has been reported. Our aim was firstly, to further characterize the clinical features and broaden the spectrum of genetic pathogenic variants in AT patients. Secondly, we aimed to study the immune profiles of AT patients and their relatives to identify similarities or common biomarkers. METHODS: A Target Gene Sequencing for six patients suspected with AT was performed. Computational analysis was conducted to assess the pathogenicity of novel variants. The distribution of immune cells was assessed by flow cytometry in patients with AT, AT-like disorder, Friedreich ataxia, and in AT relatives. The expression pattern of candidate genes was evaluated by RT-qPCR. RESULTS: We identified and predicted the pathogenicity of novel variants in the ATM gene. Computational analysis suggested that the novel identified missense mutation could affect ATP binding pattern and ATM protein flexibility, while Alu element insertion could probably induces a premature stop codon. Furthermore, our results confirm the pathogenic effect of identified splicing mutations on the ATM transcript. Moreover, we noticed a high percentage of LTCD4 + and LTCD8 + senescent subsets in AT patients and a relative increase of the of intermediate and non-classical monocytes accompanied with a decrease of classical monocytes specifically in AT patients with truncated biallelic mutations which was intriguingly similar to the immune profile of AT parents. In addition, a difference of immune pattern was observed between AT patients with biallelic truncated mutations compared to those with at least one non-truncated mutation, with a variability intragroup. Gene expression analysis identified FOXO3, IL33 and METTL3 as putative genes that may yield clues into AT pathogenesis. CONCLUSION: Taken together, our study expands the mutational spectrum of AT disease worldwide and further characterize the immune profile of AT patients uncovering a possible difference in some immune cellular subsets related to ATM mutation type and delineate putative immune abnormalities related to ATM heterozygosity among AT parents. Furthermore, dysregulation in FOXO3, IL33 and METTL3 expression could be related to disease severity.

Humans↗
PubMed2025

A novel frameshift variant leads to familial osteopetrosis with variable phenotypes in a Chinese Han consanguineous family.

Osteopetrosis, a group of highly heterogeneous genetic bone disorders, is characterized by deafness, increased bone density, hepatosplenomegaly, pancytopenia and intellectual disability. Osteopetrosis can be divided into three subtypes: autosomal recessive osteopetrosis (ARO), intermediate autosomal recessive osteopetrosis (IARO), and autosomal dominant osteopetrosis (ADO). CLCN7 has been reported to be the most common gene responsible for the ADO-II subtype. In this study, a novel variant, c.175dupA (p.Met59Asnfs*8), of CLCN7 was identified in a Chinese Han consanguineous family with suspected ADO-II. The proband was homozygous for the p.Met59Asnfs*8 variant and exhibited multiple severe phenotypes, including deafness, short stature, brittle bones, optic atrophy, hepatosplenomegaly, intellectual disability, cleft palate and recurrent infection. However, except for the mother of the proband, who presented a series of clinical phenotypes caused by bone marrow failure, all the other family members who were heterozygous had no obvious abnormal phenotypes. Our study suggested that the novel variant p.Met59Asnfs*8 in CLCN7 was very likely pathogenic factor in our suspected ADO-II family. The phenotypes of heterozygous carriers may be affected by incomplete penetrance. Loss of function of CLCN7 caused by nonsense-mediated mRNA decay (NMD) due to the frameshift variant was likely the underlying pathogenic mechanism. This study broadened the mutation spectrum of CLCN7, provided a foundation for timely and effective clinical intervention for related diseases, and demonstrates the importance of genetic counselling.

Adult↗
PubMed2024

Identification of a novel intronic variant in COL4A2 gene associated with fetal severe cerebral encephalomalacia and subdural hemorrhage.

BACKGROUND: Genetic variants in COL4A2 are less common than those of COL4A1 and their fetal clinical phenotype has not been well described to date. We present a fetus from China with an intronic variant in COL4A2 associated with a prenatal diagnosis of severe cerebral encephalomalacia and subdural hemorrhage. METHODS: Whole exome sequencing (WES) was applied to screen potential genetic causes. Bioinformatic analysis was performed to predict the pathogenicity of the variant. In in vitro experiment, the minigene assays were performed to assess the variant's effect. RESULTS: In this proband, we observed ventriculomegaly, subdural hemorrhage, and extensive encephalomalacia that initially suggested cerebral hypoxic-ischemic and/or hemorrhagic lesions. WES identified a de novo heterozygous variant c.549 + 5G > A in COL4A2 gene. This novel variant leads to the skipping of exon 8, which induces the loss of 24 native amino acids, resulting in a shortened COL4A2 protein (p.Pro161_Gly184del). CONCLUSION: Our study demonstrated that c.549 + 5G > A in COL4A2 gene is a disease-causing variant by aberrant splicing. This finding enriches the variant spectrum of COL4A2 gene, which not only improves the understanding of the fetal neurological disorders associated with hypoxic-ischemic and hemorrhagic lesions from a clinical perspective but also provides guidance on genetic diagnosis and counseling.

Female↗