PubMed HealthSearch

SEARCH · PubMed Health

Results for “ACMG”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Biochemical testing for congenital disorders of glycosylation: A technical standard of the American College of Medical Genetics and Genomics (ACMG).

Congenital disorders of glycosylation (CDG) are a large and continually expanding group of disorders that present with a variety of clinical findings and have been linked to over 170 genes. Individually, CDGs are rare; however, the true incidence may be underestimated because of the variability of the clinical findings, and the multiple testing strategies needed to diagnosis them across multiple pathways. Testing for CDGs has evolved over recent years with the availability of high-throughput molecular testing and improved gene discovery techniques. Biochemical testing to detect defects in glycosylated proteins or enzymatic deficiency still plays a critical role in the diagnosis of affected individuals, and both testing modalities are often required to finalize a diagnosis. Emerging therapeutic approaches targeting improvements in glycosylation require reliable and reproducible biochemical testing for therapeutic monitoring, dose adjustment, and avoidance of dose-related side effects. To maintain clinical sensitivity and specificity and to ensure reproducibility across laboratories performing complex biochemical testing, the American College of Medical Genetics and Genomics has developed the following technical standard.

Humans

Venous thromboembolism laboratory testing (factor V Leiden and factor II c.∗97G>A), 2025 revision: A technical standard of the American College of Medical Genetics and Genomics (ACMG).

Venous thromboembolism (VTE) occurs when a blood clot forms in a vein. The etiology of VTE is multifactorial, including both environmental and genetic factors. Among the genetic factors, factor V Leiden and factor II c.∗97G>A (formerly referred to as prothrombin 20210G>A) are the 2 most common genetic variants associated with VTE. Testing for these variants is one of the most common referrals in clinical genetics laboratories. Although the methodologies for testing these 2 variants are relatively straightforward, the clinical implementation can be complicated regarding test indications, risk assessment for occurrence, and recurrence of VTE and related genetic counseling. This document provides an overview of VTE, information about the variants and their influence on risk, considerations before initiating genetic testing, and the clinical and analytical sensitivity and specificity of the tests. Key information that should be included in the laboratory report is also provided. This document supersedes the Technical Standards and Guidelines for Venous Thromboembolism Laboratory Testing originally published in 2005 and revised in 2018. It is designed for genetic testing professionals familiar with the disease and the analysis methods.

Humans

Isolated lateralized overgrowth and the need for tumor screening: A clinical practice resource of the American College of Medical Genetics and Genomics (ACMG).

PURPOSE: To provide diagnostic guidance for individuals with lateralized overgrowth (LO) and implement appropriate screening protocols. LO without a syndromic presentation is considered idiopathic isolated lateralized overgrowth (ILO). METHODS: We performed a literature search of LO syndromes and malignancy risk and reviewed existing guidelines and expert input. RESULTS: We integrated 940 unique articles to form recommendations. We defined LO as significantly larger length and/or girth of aspect(s) of one side of the body compared with its contralateral side. It can be associated with somatic overgrowth syndromes. ILO was previously defined based on clinical features and deemed idiopathic by absence of molecular findings. Much of the tumor risk is likely because of specific LO syndromic causes now identified through improved diagnostic technologies; therefore, the tumor risk in idiopathic ILO is likely lower than previously accepted. CONCLUSION: Mosaicism complicates molecular diagnosis for children with LO. However, conditions such as Beckwith-Wiedemann spectrum and PTEN-related hamartoma tumor syndrome necessitate routine tumor screening. Establishing a specific diagnosis via comprehensive molecular testing on affected tissue will guide screening and management. In cases of idiopathic ILO, location of the overgrowth, estimation of tumor risk, regional practice approaches and family concerns all play roles in determining tumor screening.

Child

Prenatal screening for trisomy 21 (Down syndrome) using first- and second-trimester biochemistry and nuchal translucency: A technical standard of the American College of Medical Genetics and Genomics (ACMG).

This technical standard was developed as a guide for laboratories performing prenatal screening for Down syndrome. It addresses 3 topics: second trimester (triple or quad), first trimester, including incorporation of nuchal translucency, and current directions in cell-free DNA screening. Analytic methods, clinical considerations, screening performance, guidelines for reporting second trimester, first trimester, integrated, contingent, and reflex screening tests for Down syndrome, are discussed. Individual laboratories are responsible for meeting the quality assurance standards described by the Clinical Laboratory Improvement Amendments, the College of American Pathologists, and other regulatory agencies, with respect to appropriate sample documentation, assay validation, general proficiency, and quality control measures.

Humans

HCSeeker: A classification tool for human genetic variant hot and cold spots designed for PM1 and benign criteria in the ACMG-AMP guideline.

PURPOSE: The PM1 criterion, which states that a variant is located in a mutational hot spot and/or critical and well-established functional domain without benign variation (such as the active site of an enzyme), is considered moderate evidence for assessing its pathogenicity. Although guidelines from the American College of Medical Genetics and Genomics and the Association for Molecular Pathology are widely adopted, the PM1 criterion remains limited from lacking a reliable database of variant hot spots. Compared with hot spots, cold spots are neglected by the guidelines. To improve variant classification, we suggest including cold spots for supporting benign classifications. Consequently, we have developed the HCSeeker to provide data support for PM1 and the "Benign" criteria. METHODS: HCSeeker uses the Kernel Density Estimation and the Expectation-Maximization algorithm to identify hot- and cold-spot regions. RESULTS: Through HCSeeker, we identified 988 hot spots and 682 cold spots across 889 genes and provided a public database (http://www.genemed.tech/hcseeker/) for researchers and clinicians to query variant locations, facilitating the application of American College of Medical Genetics and Genomics and the Association for Molecular Pathology PM1 or "Benign" criteria. CONCLUSION: We developed the HCSeeker tool, which can effectively identify variant hot and cold spots within genes to enhance the interpretability of gene variants.

Humans

Optimizing gene panels for equitable reproductive carrier screening: The Goldilocks approach.

PURPOSE: Professional organizations recommend pan-ancestry carrier screening for autosomal recessive and X-linked conditions. Advances in DNA sequencing have allowed the analysis of hundreds of genes; however, the optimal number of genes for carrier screening remains unclear. The American College of Medical Genetics and Genomics (ACMG) has proposed a tiered approach recommending screening for 113 genes. METHODS: We analyzed ClinVar and gnomAD v4.1.0, for genes associated with serious autosomal recessive and X-linked conditions and modeled screening performance across panels of varying compositions and sizes in diverse genetic ancestries. We also reevaluated the ACMG gene list using the updated gnomAD data. RESULTS: We identified potential inconsistencies in the ACMG gene lists, particularly in the carrier test performance (defined as a positive yield) for underrepresented genetic ancestry groups. Modeling of the population data for 1310 genes revealed that the screening of 152, 248, 531, and 725 genes achieved 90%, 95%, 99%, and 99.7% positive yields, respectively, in couples. Real-world data from the screening of more than 60,000 couples were used to validate the model. CONCLUSION: Our methodology optimizes the gene content of carrier screening panels for diverse ancestry groups, provides a mechanism for continually updating guidelines, ensures consistency with genomic population data, and improves equity across populations.

Humans

Phenotypic manifestations and variant reclassification of germline PTEN variants: a nationwide Danish study.

BACKGROUND: Classification of heterozygous germline PTEN variants in patients with, or suspected of having, PTEN hamartoma tumour syndrome (PHTS) remains challenging. Accurate classification is essential as these patients require lifelong cancer surveillance. METHODS: We identified all patients with a PTEN variant previously classified as a variant of uncertain significance (VUS), likely pathogenic (LP) or pathogenic (P), collected clinical data and reclassified all variants using the latest PTEN gene-specific American College of Medical Genetics (ACMG) guidelines. Moreover, genotype-phenotype correlations were assessed. RESULTS: 167 patients from 112 families were enrolled. Eighty-seven unique PTEN variants were identified, including 20 novel variants. After applying the PTEN gene-specific ACMG guidelines, 32 variants (36.8%) were reclassified, resulting in 60 PTEN variants classified as LP/P (69.0%), 18 variants classified as VUS (20.7%), while 9 variants were classified as LB/B (10.3%). Genotype-phenotype correlation was performed among 104 patients with LP/P variants: 51 cancer cases were recorded in 41 patients and a distinct PHTS phenotype was observed in 25% of patients, with macrocephaly being present in 99% of patients with a known head circumference. Twenty-three patients had neurodevelopmental delay and/or autism, and we observed an increased prevalence of missense variants in these patients. CONCLUSION: We identified 87 different PTEN variants, and application of PTEN gene-specific ACMG guidelines led to reclassification of 32 variants (36.8%), underscoring the importance of regular variant reassessment using the most recent gene-specific guidelines, ensuring optimal patient management and surveillance.

Genetic Predisposition to Disease

WilsonGenAI a deep learning approach to classify pathogenic variants in Wilson Disease.

BACKGROUND: Advances in Next Generation Sequencing have made rapid variant discovery and detection widely accessible. To facilitate a better understanding of the nature of these variants, American College of Medical Genetics and Genomics and the Association of Molecular Pathologists (ACMG-AMP) have issued a set of guidelines for variant classification. However, given the vast number of variants associated with any disorder, it is impossible to manually apply these guidelines to all known variants. Machine learning methodologies offer a rapid way to classify large numbers of variants, as well as variants of uncertain significance as either pathogenic or benign. Here we classify ATP7B genetic variants by employing ML and AI algorithms trained on our well-annotated WilsonGen dataset. METHODS: We have trained and validated two algorithms: TabNet and XGBoost on a high-confidence dataset of manually annotated, ACMG & AMP classified variants of the ATP7B gene associated with Wilson's Disease. RESULTS: Using an independent validation dataset of ACMG & AMP classified variants, as well as a patient set of functionally validated variants, we showed how both algorithms perform and can be used to classify large numbers of variants in clinical as well as research settings. CONCLUSION: We have created a ready to deploy tool, that can classify variants linked with Wilson's disease as pathogenic or benign, which can be utilized by both clinicians and researchers to better understand the disease through the nature of genetic variants associated with it.

Hepatolenticular Degeneration

Identification of pathogenic variants in six Chinese families with keratoconus of autosomal dominant inheritance: pathogenicity analysis and variable phenotype.

PURPOSE: Keratoconus (KC) is a bilateral, asymmetric disease causing corneal thinning, irregular astigmatism, and vision decline, with unclear etiology. This study aims to investigate pathogenic variants of candidate genes in Chinese KC families via whole exome sequencing (WES). METHODS: The Pentacam 3D anterior segment analysis system was applied for keratectasia detection, and the Corvis ST was used for corneal biomechanics measurement. Probands from KC families were screened via WES and further verified in other family members through Sanger sequencing. Additionally, qPCR was used to validate copy number variants and identify pathogenic gene loci. The identified variants were then classified according to the Standards and Guidelines for the Interpretation of Sequence Variants published by the American College of Medical Genetics and Genomics (ACMG). Finally, STRING protein-protein interaction (PPI) networks analysis was performed to investigate interactions among candidate gene-related proteins. RESULTS: Using WES, four heterozygous missense variants were detected in the ZNF469, KRT12, COL8A2, and COL18A1 genes: c.4384G > A: p.Asp1462Asn, c.1229T > G:p.Val410Gly, c.505A > G:p.Ile169Val, and c.1159G > A:p.Gly387Arg. Additionally, a heterozygous frameshift variant was detected in the PMS2 gene: c.1551_1572del:p.Ser517Argfs*71. The affected parents carried the same variants as the probands verified by Sanger sequencing. A copy number variant was detected in the DPP6 gene: seq[GRCh38] dup(7)(q36.2q36.2) chr7:g.153782360_ 153982491dup. According to ACMG guidelines, ZNF469, KRT12, COL8A2, and COL18A1 gene variants are Likely Pathogenic; PMS2 and DPP6 gene variants are Pathogenic. STRING analysis highlights a tightly interconnected network centered on COL8A2, involving COL18A1, FN1, ZNF469, and KRT12. DPP6 was involved in KC via affecting FN1. In four of six autosomal dominant KC (adKC) families, affected parents had the same variants as probands but milder phenotypes. CONCLUSION: In this study, six novel variants in ZNF469, KRT12, COL8A2, COL18A1, PMS2, and DPP6 were linked to adKC. Family phenotypes showed variable expressivity with irregular dominance inheritance. Abnormal KC-related gene protein expression may contribute to corneal structural instability. This study broadened KC genetic screening candidates and suggested genetic testing could aid early KC diagnosis and intervention.

Adult

A novel missense mutation in tropomyosin 1 gene associated with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a common genetic heart disorder that can lead to heart failure or sudden death. Family-based identification of rare sarcomeric variants can support molecular diagnosis and cascade screening in inherited HCM. This study aimed to identify and evaluate a novel TPM1 variant found in a Vietnamese family with HCM. The proband, a 3-year-old boy diagnosed with HCM, and eight relatives from three generations underwent clinical and genetic evaluation. A candidate variant initially identified by targeted next-generation sequencing was validated by PCR and Sanger sequencing. Familial segregation analysis was performed, and variant pathogenicity was assessed according to ACMG guidelines with support from in silico prediction and structural modeling. Sanger sequencing confirmed a heterozygous missense variant in exon 6 of TPM1 NM_001018005.2:c.576G > C, p.(Glu192Asp), in the proband, his father, and paternal grandfather, all of whom exhibited clinical signs of HCM. The variant was absent in unaffected relatives and in public population databases. Based on ACMG criteria (PM1, PM2, PM5, and PP3), the variant was classified as likely pathogenic. This novel TPM1 variant segregated with HCM in a Vietnamese family, expands the known mutational spectrum of TPM1 in hypertrophic cardiomyopathy, and warrants further functional investigation and familial genetic evaluation.

American College of Medical Genetics and Genomics

Validating the splicing effect of rare variants in the SLC26A4 gene using minigene assay.

BACKGROUND: The SLC26A4 gene is the second most common cause of hereditary hearing loss in human. The aim of this study was to utilize the minigene assay in order to identify pathogenic variants of SLC26A4 associated with enlarged vestibular aqueduct (EVA) and hearing loss (HL) in two patients. METHODS: The patients were subjected to multiplex PCR amplification and next-generation sequencing of common deafness genes (including GJB2, SLC26A4, and MT-RNR1), then bioinformatics analysis was performed on the sequencing data to identify candidate pathogenic variants. Minigene experiments were conducted to determine the potential impact of the variants on splicing. RESULTS: Genetic testing revealed that the first patient carried compound heterozygous variants c.[1149 + 1G > A]; [919-2 A > G] in the SLC26A4 gene, while the second patient carried compound heterozygous variants c.[2089 + 3 A > T]; [919-2 A > G] in the same gene. Minigene experiments demonstrated that both c.1149 + 1G > A and c.2089 + 3 A > T affected mRNA splicing. According to the ACMG guidelines and the recommendations of the ClinGen Hearing Loss Expert Panel for ACMG variant interpretation, these variants were classified as "likely pathogenic". CONCLUSIONS: This study identified the molecular etiology of hearing loss in two patients with EVA and elucidated the impact of rare variants on splicing, thus contributing to the mutational spectrum of pathogenic variants in the SLC26A4 gene.

Humans

Clinical and molecular characterization of TCF12 variants in an Asian pediatric cohort with craniosynostosis.

BACKGROUND: Craniosynostosis is a genetically heterogeneous craniofacial disorder caused by the premature fusion of one or more cranial sutures. Pathogenic variants in TCF12, encoding a basic helix-loop-helix (bHLH) transcription factor, represent a major cause of autosomal dominant coronal craniosynostosis and are characterized by incomplete penetrance and marked phenotypic variability. However, clinical and molecular data from Asian pediatric populations remain limited. METHODS: Trio-based whole-exome sequencing was performed on ten pediatric patients with cranial deformities and their parents. The identified TCF12 variants were classified according to the American College of Medical Genetics and Genomics (ACMG) guidelines and validated by Sanger sequencing. Detailed clinical and radiological data were collected. In addition, a comprehensive literature review was conducted to summarize previously reported TCF12 variants and associated phenotypes. RESULTS: Ten distinct heterozygous TCF12 variants were identified in ten unrelated pediatric patients, all of which were classified as pathogenic or likely pathogenic according to ACMG criteria. Six variants were inherited, and four occurred de novo. Seven patients had imaging-confirmed craniosynostosis, predominantly involving the coronal sutures (five bilateral and one unilateral), while one patient presented with multisuture craniosynostosis (left coronal and sagittal sutures). Three patients showed cranial deformities without radiographic evidence of suture fusion. Phenotypic heterogeneity and incomplete penetrance were observed, including a mildly affected parent. Most pathogenic variants were truncating variants distributed mainly across exons 14-19 and predicted to induce loss of function, either through nonsense-mediated mRNA decay or the production of truncated proteins lacking the entire C-terminal bHLH domain. Structural modeling analysis further indicated that the bHLH-domain-located missense variant p.Arg603Trp alters the local DNA-binding conformation of TCF12 and impairs its binding affinity to the E-box DNA motif. CONCLUSIONS: This study provides additional clinical and molecular data on TCF12-related craniosynostosis in a pediatric cohort from an Asian population. Our findings support haploinsufficiency as the central pathogenic mechanism, primarily driven by truncating variants affecting the C-terminal bHLH domain. The marked clinical heterogeneity, the presence of mild or evolving phenotypes, and incomplete penetrance observed in our cohort underscore the importance of early diagnosis and longitudinal clinical surveillance in affected families.

Humans

[Genetic analysis of a fetus with Short-rib thoracic dysplasia 8 with or without polydactyly due to variants of DYNC2I1 gene].

OBJECTIVE: To investigate the clinical characteristics of a fetus with Short-rib thoracic dysplasia 8 with or without polydactyly (SRTD8) due to variants of DYNC2I1 gene. METHODS: A fetus identified to have short ribs, short long bones, and narrow thorax at 26+1 weeks of gestation at the Women and Children's Hospital of Ningbo University in September 2024 was selected as study subject. The fetus underwent termination of pregnancy at 35+5 weeks of gestation. Clinical data of the fetus were retrospectively collected. Whole exome sequencing (WES) was carried out on fetal tissue, and candidate variants were validated by Sanger sequencing. Difference between the wild type and variant DYNC2I1 proteins was analyzed using AlphaFold v3.0.1 and PyMOL v2.5.6 software. Pathogenicity of the variant was rated based on guidelines from the American College of Medical Genetics and Genomics (ACMG). Using keywords such as "DYNC2I1 gene", previous literature on patients due to biallelic DYNC2I1 gene variants were retrieved from the PubMed databases, CNKI, and Wanfang Data Knowledge Service Platform, and the genetic variant and clinical phenotypes of patients were analyzed. The literature retrieval time was set from the establishment of database to December 31, 2025. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2023-094). RESULTS: Prenatal ultrasound revealed that the fetus had short ribs, short long bones, and narrow thorax at 26+1 gestational weeks. WES and Sanger sequencing revealed that the fetus has harbored compound heterozygous variants of the DYNC2I1 gene, namely c.265_268 (p.Gln89GlyfsTer15) in exon 3 and c.1777C>T (p.Arg593Trp) in exon 14, which were inherited from his father and mother, respectively. Prediction of the DYNC2I1 protein structure suggested that the c.265_268del variant has formed a premature termination codon, which may significantly alter the protein's secondary structure. The c.1777C>T variant may disrupt the electrostatic interaction between Arg593 and Asp729. Based on the ACMG guidelines, the c.265_268del (p.Gln89GlyfsTer15) variant was predicted to be likely pathogenic (PM2_Supporting +PVS1), whilst the c.1777C>T(p.Arg593Trp) variant was rated as uncertain significance (PM2_Supporting+PM3+PP4). Literature search has identified five articles related to biallelic DYNC2I1 variants involving a total of 11 fetuses/patients. Together with the fetus from this study, typical phenotypes included short ribs (6 cases), narrow thorax (6 cases), short limb bones (6 cases), and hand polydactyly (6 cases), and foot polydactyly (5 cases), albeit with significant clinical heterogeneity. A total of 12 genetic variants were identified, among which c.44delC was the most common (16.7%, 4/24), followed by c.1777C>T, c.2246C>T, and c.2305G>A (each accounting for 12.5%). No mutational hotspot was identified. CONCLUSION: The c.265_268del (p.Gln89GlyfsTer15) and c.1777C>T (p.Arg593Trp) compound heterozygous variants of the DYNC2I1 gene probably underlay the pathogenesis of SRTD8 in this fetus. This study has enriched the mutational spectrum of the DYNC2I1 gene and facilitated etiological diagnosis and treatment of DYNC2I1-related diseases.

Humans

[Genetic analysis of a male with Multiple morphological abnormalities of sperm flagella combined with sperm head abnormalities due to compound heterozygous variants of DNAH1 gene and a literature review].

OBJECTIVE: To explore the clinical phenotype and genetic etiology of a male with Multiple morphological abnormalities of sperm flagella (MMAF) combined with sperm head abnormalities due to compound heterozygous variants of DNAH1 gene, with an aim to provide guidance for assisted reproductive technology in his family. METHODS: A man with MMAF combined with sperm head abnormalities who visited Women and Children's Hospital of Ningbo University in October 2024 was selected as study subject. Clinical data of the patient's family were retrospectively collected. Peripheral blood samples were collected from the patient and his spouse, and G-banding karyotyping and whole exome sequencing (WES) were carried out. Candidate variants were validated by Sanger sequencing. Conservation of the DNAH1 protein was queried on the UCSC website. The difference between wild type and variant DNAH1 proteins were analyzed using AlphaFold v3.0.1 and PyMOL v2.5.6. The pathogenicity of variant was rated based on the guidelines from American College of Medical Genetics and Genomics (ACMG). Previous literature was searched using keywords "DNAH1 gene" and "multiple morphological abnormalities of the sperm flagella" on CNKI, Wanfang Data Knowledge Service Platform, and PubMed database to identify cases of MMAF attributed to biallelic DNAH1 gene variants. The retrieval period was set from the establishment of the databases to December 31, 2025. The genotypes and clinical phenotypes of patients with biallelic DNAH1 mutations were analyzed. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: EC2023-094). RESULTS: The 30-year-old patient and his 30-year-old wife had infertility for 2 years. Semen analysis revealed no motile sperm and a 99.0% abnormal morphology rate. Typical MMAF was observed with phase-contrast microscopy. Sperm morphology analysis revealed abnormalities of the head, neck, and tail with an approximate ratio of 9:5:1. The patient's karyotype was 46,XY, and his wife's karyotype was 45,X[4]/47,XXX[1]/46,XX[84]. WES and Sanger sequencing revealed that the patient harbored compound heterozygous variants of the DNAH1 gene, namely c.1435_1444+3del and c.12204_12206del (p.Asn4069del), but their origin remained unidentified. UCSC genome browser query results showed that the amino acid residue at position 4 069 of the DNAH1 protein is highly conserved across various species. Protein structure prediction reveals that, in the wild-type DNAH1 protein, the Asparagine at position 4 069 (Asn4069) can form hydrogen bonds with the Leucine on the main chain at position 4 086 (Leu4086) and the Serine on the side chain at position 4 087 (Ser4087). The c.12204_12206del variant, resulting in deletion of Asn4069, disrupts these hydrogen bonds and does not generate any compensatory interactions. Based on the ACMG guidelines, the c.1435_1444+3del variant was predicted to be likely pathogenic (PM2_Supporting+PVS1), and the c.12204_12206del(p.Asn4069del) variant was rated as likely pathogenic (PM2_Supporting+PM4+PM3+PP4). The couple had elected for in vitro fertilization using donor sperm. During this cycle, 12 oocytes were retrieved, 10 oocytes were successfully fertilized, 1 embryo and 6 blastocysts were obtained. Following the first transfer of a frozen-thawed blastocyst, implantation of an empty gestational sac occurred, which led to a miscarriage. After the second transfer of a high-quality blastocyst, the embryo split into twins following implantation, and the spouse had selected fetal reduction. The gestational age was 33+3 weeks on June 1, 2026. Literature review identified three studies reporting biallelic mutations of the DNAH1 gene in association with MMAF combined with sperm head abnormalities. Together with the patient from this study, a total of 20 patients were included in the analysis. The rate of sperm flagellar abnormalities in these patients was above 80.0%, while the rate of sperm head abnormalities has ranged from 12.0% to 100.0%. In four patients, the genetic basis was unknown. In the remaining 16 patients, 35 mutations were detected, with c.8626-1G>A being the most common (22.9%, 8/35). CONCLUSION: This patient showed MMAF with frequent sperm head defects. Compound heterozygous variants of the DNAH1 gene probably underlay these abnormalities, which in turn has led to his primary infertility. This study revealed the phenotypic variability of MMAF and broadened the mutational spectrum of the DNAH1 gene.

Humans

[Pathogenicity analysis and prenatal genetic counseling for five Chinese pedigrees harboring a hemizygous c.-32C>G variant of FGF13 gene].

OBJECTIVE: To explore the pathogenicity and prenatal counseling strategies for five Chinese pedigrees harboring a hemizygous c.-32C>G (NM_001139500.2) variant of fibroblast growth factor 13 (FGF13) gene. METHODS: Five Chinese pedigrees found to carry a hemizygous c.-32C>G variant of the FGF13 gene at the Prenatal Diagnosis Center of Henan Provincial People's Hospital between January 2024 and January 2025 were selected as study subjects. The pedigrees had undergone prenatal diagnosis for a family history of genetic disorders, abnormal fetal ultrasound findings, or advanced maternal age. A retrospective analysis was carried out, wherein clinical data for all members of the pedigrees were obtained through the medical records system and outpatient visit system. Peripheral blood samples were collected from all pedigree members, and amniotic fluid samples were obtained from the probands. Following extraction of genomic DNA, prenatal diagnosis was performed using chromosomal microarray analysis (CMA) and trio whole-exome sequencing (trio-WES). Sanger sequencing was used to determine the carrier status for the candidate variant, and Mini-Mental State Examination (MMSE) was used to assess the cognitive function of hemizygous individuals carrying the FGF13 gene c.-32C>G variant. Pathogenicity of candidate variant was assessed based on guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2021-171). RESULTS: CMA and trio-WES revealed no pathogenic variants in all probands, whilst trio-WES and Sanger sequencing had identified 11 male individuals carrying a hemizygous c.-32C>G variant of the FGF13 gene from the five pedigrees, which included six adult males, a young boy, and four fetuses. One fetus had undergone termination of pregnancy due to hydrocephalus, one was born pre-term at 34+1 weeks of gestation owing to maternal hypertension, and other two were delivered at full term. Follow-up of the survived males revealed no phenotypic manifestations related to language or intellectual impairment. Among these, three adult males underwent the MMSE assessment, all of whom showed normal cognitive function. Search of the gnomAD database suggested the carrier frequency of FGF13 c.-32C>G variant in the East Asian population to be 0.125%, with 11 hemizygous males documented. Three male patients harboring the variant showed severe intellectual disability. Both in vitro and in vivo studies suggested that it could reduce the translation levels of FGF13 protein. Based on the ACMG guidelines, it was classified as variant of uncertain significance (BS4+PS3_Supporting). CONCLUSION: There is insufficient evidence to classify the FGF13 c.-32C>G as a pathogenic variant in clinical practice, and its presence should not be considered an indication for pregnancy termination due to major birth defects.

Adult

Expansion of the allelic and phenotypic spectrum of MED25-related developmental disorder: novel compound heterozygous variants with structural domain implications.

MED25-related developmental disorder (Basel-Vanagaite-Smirin-Yosef syndrome) is a rare autosomal recessive disorder, defined by severe neurodevelopmental delay, corpus callosum abnormalities, ocular involvement, epilepsy, and marked facial appearance. MED25 pathogenic variants interfere with the functioning of the Mediator complex, which is responsible for RNA polymerase II transcription. We report a 9-year-old girl who presents with significant global developmental delay, agenesis of the corpus callosum, congenital cataracts, epilepsy, hypotonia, musculoskeletal abnormalities, and typical craniofacial features. Trio-based whole-exome sequencing revealed compound heterozygous variants in MED25: a maternally transmitted truncating variant (c.1366 C > T; p.Gln456*) and a paternally inherited missense variant (c.430 C > T; p.Leu144Phe). The new classification of the missense variant as potentially pathogenic is supported by a systematic ACMG re-evaluation supported by segregation analysis, phenotypic specificity, computational prediction, and structural localization in the MED25 Activator Interaction Domain (ACID). Comparative phenotypic analyses show strong agreement with reported cases but add more data to fine-tune clinical spectrum. This article broadens the allelic and phenotypic spectrum of MED25-related developmental disorder and highlights the need for comprehensive evaluation across molecular, structural, and phenotypic pathways to elucidate variant signature in rare genetic disease models correctly.

Humans