Inês Querido, Carla Pinto, Patrícia Arinto, Andreia Brandão, Catarina Santos, Manuela Pinheiro, Joana Guerra, João Silva, Ana Peixoto, Manuel R Teixeira
{"title":"A Novel Deleterious Variant and a Founder Effect in Four New Families of MBD4-Associated Neoplasia Syndrome Recruited Over a Period of 20 Years.","authors":"Inês Querido, Carla Pinto, Patrícia Arinto, Andreia Brandão, Catarina Santos, Manuela Pinheiro, Joana Guerra, João Silva, Ana Peixoto, Manuel R Teixeira","doi":"10.1111/cge.70014","DOIUrl":"https://doi.org/10.1111/cge.70014","url":null,"abstract":"<p><p>DNA glycosylases play a crucial role in DNA repair mediated by the base excision repair (BER) pathway, and alterations in these enzymes have been associated with hereditary cancer predisposition. Recently, germline biallelic loss-of-function variants in MBD4 were shown to be responsible for a novel autosomal recessive multi-tumor predisposition syndrome, provisionally denominated as MBD4-associated neoplasia syndrome and characterized by the association of adenomatous polyposis, colorectal cancer, and acute myeloid leukemia (AML). Here, we studied the MBD4 gene in five individuals from four families affected by adenomatous polyposis and AML, who had been referred for genetic counselling at a single institution over a period of approximately 20 years. All patients with this phenotype presented homozygous deleterious germline variants in MBD4, of which one is a founder variant recurrent in three of the families, and another variant has not been previously described in the literature. Our work allowed a molecular diagnosis for these families and significantly contributes to expanding the knowledge about this emerging syndrome caused by MBD4 constitutional deficiency.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xingyu Feng, Yao Hu, Xiaojuan Wang, Lin Zhou, Chulong Xiong, Na Ma, Hui Xi
{"title":"Non-Canonical Splice Site Variant in FREM1 Result in Fetal Renal Agenesis.","authors":"Xingyu Feng, Yao Hu, Xiaojuan Wang, Lin Zhou, Chulong Xiong, Na Ma, Hui Xi","doi":"10.1111/cge.70016","DOIUrl":"https://doi.org/10.1111/cge.70016","url":null,"abstract":"<p><p>Loss-of-function variants in FREM1 have been demonstrated in Manitoba oculotrichoanal syndrome (MOTA) and bifid nose, renal agenesis, and anorectal malformations (BNAR) syndrome, but the broader phenotypic spectrum of FREM1 variants remains incompletely characterized. In this study, we report compound heterozygous variants in a prenatal case of bilateral renal agenesis. Exome sequencing revealed biallelic FREM1 variants: c.5622G>A (p.Trp1874*) and c.3274+4A>G (p.Gly1030_Ile1091del). Minigene and bioinformatic analyses confirmed that the splice site variant induces aberrant splicing and alters transcriptional expression levels. This finding underscores the crucial role of non-canonical splice site variants in FREM1 in the pathogenesis of bilateral renal agenesis.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Valentina Lodato, Massimo Galli, Giacomo D'Angeli, Irene Bottillo, Luca Celli, Rosaria Turchetta, Andrea Colizza, Francesca Gianno, Biagio Palmisano, Francesca Romana Federici Stanganelli, Maria Rita Bianco, Daniela Messineo, Eugenia Allegra, Paola Grammatico, Mara Riminucci, Alessandro Corsi
{"title":"Novel Pathogenic Variant Confirms the Association of REST and Jones Syndrome.","authors":"Valentina Lodato, Massimo Galli, Giacomo D'Angeli, Irene Bottillo, Luca Celli, Rosaria Turchetta, Andrea Colizza, Francesca Gianno, Biagio Palmisano, Francesca Romana Federici Stanganelli, Maria Rita Bianco, Daniela Messineo, Eugenia Allegra, Paola Grammatico, Mara Riminucci, Alessandro Corsi","doi":"10.1111/cge.70017","DOIUrl":"https://doi.org/10.1111/cge.70017","url":null,"abstract":"<p><p>Jones syndrome (JS) is an ultra-rare autosomal dominant condition characterized by gingival fibromatosis and progressive sensorineural hearing loss. It has been recently demonstrated in members of a Finnish family to co-segregate with heterozygosity for a frameshift variant in the fifth and last exon of the repressor element 1-silencing transcription factor gene (REST). Here, we report the first Italian family in which JS was diagnosed in the proband, a 38-year-old woman, and in her mother. Exome Sequencing identified in both, but not in clinically unaffected members of the family (i.e., a sister and the brother of the proband), the heterozygous pathogenic variant c.2645T>G (p.Leu882*) in exon-5 of the REST gene. This study confirms that exon-5 REST variants cause JS.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Six New Cases of 22q13.2 Gain Including TFC20: First Report of Triplication and Smallest Duplication Associated With Neurodevelopmental Delays.","authors":"Etienne Bizot, Dima Jouni, Caroline Rooryck, Juliet Taylor, Marine Legendre, Lorelei Charbonnier, Julia Metreau, Emmanuelle Benaloun, Audrey Pinson, Geneviève Quenum, Jérôme Bouligand, Gérard Tachdjian, Philippe Labrune, Lucie Tosca","doi":"10.1111/cge.14781","DOIUrl":"https://doi.org/10.1111/cge.14781","url":null,"abstract":"<p><p>To date, only one study describes three unrelated cases of neurodevelopmental disorders associated with duplications in 22q13.2, which include the TCF20 gene. In contrast, TCF20 variants and deletions are well characterized. Here, we report six new cases of 22q13.2 gain, including TCF20, identified through array-comparative genomic hybridization (array-CGH). Probands exhibited neurodevelopmental delay, and several presented with facial dysmorphism, abnormal growth parameters, and abnormalities affecting the skeletal, respiratory, genitourinary, and/or cardiovascular systems. We documented one 440 Kb triplication and five cases of duplication ranging from 82.5 Kb to 3.03 Mb in size. Co-segregation analysis of the CNV and clinical symptoms supports variable expressivity. However, the complete penetrance of these gains remains questionable compared to the known pathogenic variants and structural variations associated with loss of function. We discuss the genotype-phenotype correlations and hypotheses surrounding the impairment of TCF20 protein function.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mahmoud R Fassad, Sebastian Valenzuela, Monika Oláhová, Jack J Collier, Charlotte V Y Knowles, Eleni Mavraki, Miriam Elbracht, Nergis Güzel, Thomas Herberhold, Ingo Kurth, Andrea Maier, Larissa Mattern, Carol Saunders, Helen McCullagh, Katrin Õunap, Saskia B Wortmann, Andre Reis, Lei Zhang, Claes M Gustafsson, Robert McFarland, Robert W Taylor
{"title":"Expanding the Genetic and Phenotypic Spectrum of POLRMT-Related Mitochondrial Disease.","authors":"Mahmoud R Fassad, Sebastian Valenzuela, Monika Oláhová, Jack J Collier, Charlotte V Y Knowles, Eleni Mavraki, Miriam Elbracht, Nergis Güzel, Thomas Herberhold, Ingo Kurth, Andrea Maier, Larissa Mattern, Carol Saunders, Helen McCullagh, Katrin Õunap, Saskia B Wortmann, Andre Reis, Lei Zhang, Claes M Gustafsson, Robert McFarland, Robert W Taylor","doi":"10.1111/cge.70011","DOIUrl":"https://doi.org/10.1111/cge.70011","url":null,"abstract":"<p><p>Mitochondrial diseases are a complex group of conditions exhibiting significant phenotypic and genetic heterogeneity. Genomic testing is increasingly used as the first step in the diagnostic pathway for mitochondrial diseases. We used next-generation sequencing followed by bioinformatic data analysis to identify potentially damaging variants in the POLRMT gene (NM_005035.4) in six new affected individuals. Structural protein analysis predicted the detrimental impact of variants on POLRMT protein structure. Patients show extended phenotypic abnormalities often presenting early in life with features including global developmental delay, cognitive impairment, short stature and muscular hypotonia. This study expands the genetic and phenotypic landscape of mitochondrial disease associated with POLRMT variants.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chiara Minotti, Sara Terreri, Andrea Del Fattore, Francesca Romana Lepri, Rosario Ruta, Maria Iascone, Laura Pezzoli, Maria Lisa Dentici, Antonio Novelli, Michelina Armando, Daniela Longo, Giuseppe Novelli, Domenico Barbuti, Andrea Bartuli, Ugo Cavallari, Ludovico Graziani, Maria Cristina Digilio, Lorenzo Sinibaldi
{"title":"Further Exploring the TRRAP Genotype-Phenotype Correlations: Report of Three New Patients With A Focus on Skeletal Anomalies.","authors":"Chiara Minotti, Sara Terreri, Andrea Del Fattore, Francesca Romana Lepri, Rosario Ruta, Maria Iascone, Laura Pezzoli, Maria Lisa Dentici, Antonio Novelli, Michelina Armando, Daniela Longo, Giuseppe Novelli, Domenico Barbuti, Andrea Bartuli, Ugo Cavallari, Ludovico Graziani, Maria Cristina Digilio, Lorenzo Sinibaldi","doi":"10.1111/cge.70013","DOIUrl":"https://doi.org/10.1111/cge.70013","url":null,"abstract":"<p><p>TRRAP encodes a multidomain pseudokinase involved in histone acetyltransferase complexes. TRRAP pathogenic variants were linked to neurodevelopmental disorders, intellectual disability, congenital anomalies, and hearing loss. We report on three unrelated patients with TRRAP missense variants. Patient #1, a girl with severe intellectual disability, autism features, and preaxial polydactyly, displays the c.5575C>T, p.(Arg1859Cys) variant. Patient #2, a boy with developmental delay and facial anomalies, harbors the c.5647G>A, p.(Gly1883Arg) variant. Patient #3, a girl with developmental delay, epilepsy, and renal artery stenosis, carries the c.8572C>T, p.(Arg2858Trp) variant. These new cases broaden the TRRAP phenotypic spectrum, updating genotype-phenotype correlations. Osteoclast differentiation in Patient #1 and TRRAP expression in osteoclasts and osteoblasts were analyzed, leading to the assumption of a role of TRRAP in bone remodeling and in the observed skeletal anomalies.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144526658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anne-Laure Chong, Alejandro Mejia-Garcia, Supriya Behl, Zaki El Haffaf, Sébastien Chénier, Bruno Maranda, Valérie Désilets, Sébastien Lévesque, Lysanne Castonguay, Anne-Marie Mes-Masson, Sylvie Giroux, François Rousseau, Nancy Hamel, George Chong, Simon Gravel, William D Foulkes
{"title":"PMS2 c.2117del (p.Lys706Serfs*19) is the Most Frequent Cancer-Associated Founder Pathogenic Variant in the French-Canadian Population of Quebec, Canada.","authors":"Anne-Laure Chong, Alejandro Mejia-Garcia, Supriya Behl, Zaki El Haffaf, Sébastien Chénier, Bruno Maranda, Valérie Désilets, Sébastien Lévesque, Lysanne Castonguay, Anne-Marie Mes-Masson, Sylvie Giroux, François Rousseau, Nancy Hamel, George Chong, Simon Gravel, William D Foulkes","doi":"10.1111/cge.14784","DOIUrl":"10.1111/cge.14784","url":null,"abstract":"<p><p>We identified a PMS2 variant (NM_000535.7:c.2117del, p.Lys706Serfs*19) in 22 French-Canadian (FC) families from Quebec with Lynch syndrome (LS; n = 21) or constitutional mismatch repair deficiency (CMMRD; n = 1). We aimed to (a) confirm its founder origin, (b) assess its allele frequency in the FC population, and (c) determine its contribution to the risk of developing various cancers in this population. We identified a haplotype common to all c.2117del alleles spanning 666 kb to 1.37 Mb, confirming the founder nature of the variant. In affected cases, the variant was found in 0 out of 821 breast cancer cases, 8 out of 693 (1.15%) endometrial cancer (EC) cases, and 1 out of 191 (0.52%) colorectal cancer (CRC) cases. In unaffected persons, the variant was identified in 22/6347 newborns (0.35%) and in 21/18129 FC CARTaGENE cohort participants (0.12%). Within this cohort, an excess of CRC (odds ratio: 10.7; 95% CI: 1.42-80.1; p value = 0.022), but not EC, was seen among heterozygotes for the PMS2 founder variant. Analysis of the variant in 24 subregions of Quebec showed over-representation in 5 of them. Here, we report the most frequent genetic cause of mismatch repair deficiency syndromes identified thus far in the FC population of Quebec.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144367956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nikolaos M Marinakis, Afrodite Kampouraki, Danai Veltra, Faidon-Nikolaos Tilemis, Maria Vasilopoulou, Aikaterini Dokou, Elissavet Georgiadou, Euthalia Karavergou, Maria Christolouka, Alexis Alexopoulos, Dimitra Kirillidi, Maria Goudesidou, Konstantina Kosma, Christalena Sofocleous, Periklis Makrythanasis
{"title":"Unraveling the Role of WDR91: Case Report of a Previously Unrecognized Clinical Entity.","authors":"Nikolaos M Marinakis, Afrodite Kampouraki, Danai Veltra, Faidon-Nikolaos Tilemis, Maria Vasilopoulou, Aikaterini Dokou, Elissavet Georgiadou, Euthalia Karavergou, Maria Christolouka, Alexis Alexopoulos, Dimitra Kirillidi, Maria Goudesidou, Konstantina Kosma, Christalena Sofocleous, Periklis Makrythanasis","doi":"10.1111/cge.70012","DOIUrl":"https://doi.org/10.1111/cge.70012","url":null,"abstract":"<p><p>WDR91, a WD40 repeat domain-containing protein, is a key regulator of endosomal trafficking, lysosomal function, and autophagy. It acts as a Rab7 effector, forming a complex with WDR81 to modulate phosphatidylinositol 3-kinase (PI3K) activity, endosomal maturation, and lysosome homeostasis. Loss-of-function variants in WDR91 are considered related to endosomal accumulation, impaired cargo degradation, and neurodegeneration. In this report, an autosomal recessive neurodevelopmental disorder is proposed, associated with WDR91 loss-of-function in a consanguineous family. The patient presented with severe microcephaly, dysmorphic features, and organomegaly, along with early onset psychomotor delay, hypotonia, sensorineural hearing impairment, and visual impairment. Whole-exome sequencing (WES) identified a homozygous splice site variant, NM_014149.4:c.1395+1G>A, predicted to disrupt the donor site and classified as likely pathogenic (PVS1, PM2). The variant was absent from population databases and our internal in-house cohort. Functional analysis supports a pathogenic role for the variant. WDR91 deficiency results in neuronal loss, cortical thinning, and impaired brain development, as evidenced in Wdr91 knockout models. Our study expands the clinical and genetic spectrum of WDR91-related disorders and highlights the need for further investigations to elucidate the precise molecular mechanisms underlying WDR91-associated pathogenesis.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144474057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexanne Cuillerier, Andrea Goodman, Chloe Lawrence, Noémie Villeneuve-Cloutier, Christine M Armour, Priya T Bhola, Danielle K Bourque, Melissa T Carter, Joanna Lazier, Sarah L Sawyer, Maha Saleh, Chitra Prasad, Victoria M Siu, Kym M Boycott, Taila Hartley, David A Dyment, Tugce B Balci
{"title":"Diagnostic Utility of Exome Data Reanalysis After In Silico Multi-Gene Panels or Clinical Exome Testing for Patients With Epilepsy and Developmental Delay/Intellectual Disability: A Retrospective Cohort Study.","authors":"Alexanne Cuillerier, Andrea Goodman, Chloe Lawrence, Noémie Villeneuve-Cloutier, Christine M Armour, Priya T Bhola, Danielle K Bourque, Melissa T Carter, Joanna Lazier, Sarah L Sawyer, Maha Saleh, Chitra Prasad, Victoria M Siu, Kym M Boycott, Taila Hartley, David A Dyment, Tugce B Balci","doi":"10.1111/cge.70008","DOIUrl":"10.1111/cge.70008","url":null,"abstract":"<p><p>Epilepsy is a relatively common condition with genetic factors contributing significantly to its etiology. Advances in next-generation sequencing have dramatically increased the number of known epilepsy genes, improving diagnostic capabilities and patient care. However, 50%-80% of epilepsy patients remain undiagnosed after genomic testing, which includes chromosomal microarray, multigene panels, and genome-wide sequencing. Reanalysis of existing exome sequencing data has shown promise in increasing diagnostic yield. In this study, we reanalyzed exome sequencing data from 87 individuals with unsolved epilepsy and developmental delay or intellectual disability in Ontario, Canada. Our approach combined clinical and translational research methodologies to identify genetic variants linked to epilepsy. We obtained a diagnostic yield of 14.9%, solving 13 participants, with 11 involving known genes and two novel gene discoveries. In addition, 11 potential diagnoses were identified, suggesting that further investigation could confirm additional diagnoses. Factors such as the inclusion of additional family data, new disease-gene associations, and technological advancements contributed to these findings. This study highlights the importance of reanalysis as a cost-effective and timely approach to improving diagnostic yield in epilepsy associated with neurodevelopmental delay.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144367955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adella Karam, Clarisse Delvallée, Bénédicte Gérard, Elodie Javey, Pascal Kessler, Valérie Pelletier, Jean-Baptiste Lamouche, Nicolas Le May, Jean Muller, Hélène Dollfus
{"title":"PIK3C2A-Related Clinical Phenotype and Cellular Charaterization Linked to Functional SHH Primary Cilia Defect.","authors":"Adella Karam, Clarisse Delvallée, Bénédicte Gérard, Elodie Javey, Pascal Kessler, Valérie Pelletier, Jean-Baptiste Lamouche, Nicolas Le May, Jean Muller, Hélène Dollfus","doi":"10.1111/cge.70005","DOIUrl":"10.1111/cge.70005","url":null,"abstract":"<p><p>PIK3C2A is a member of the class II phosphatidylinositol-3-kinases (PI3K) family that catalyzes the phosphorylation of phosphatidylinositol (PI) into PI(3)P and of PI(4)P into PI(3,4)P2. These second messenger lipids regulate a wide range of downstream signaling pathways involved in many physiological functions and cellular processes, including cell proliferation, growth, survival, motility, and metabolism. PIK3C2A is also involved in the regulation of primary cilia formation and maintenance and in the regulation of receptor-mediated endocytosis at the base of the cilium. PIK3C2A was recently related to a novel oculoskeletodental syndrome (OCSKD MIM#618440), combining short stature, coarse facial features, ocular, and skeletal abnormalities. We describe here the fifth family presenting a PIK3C2A-related syndrome characterized by pulverulent cataracts and deafness. Using trio exome sequencing, we identified two novel compound heterozygous variants in PIK3C2A for which functional testing was necessary to assess the effect of one of the variants. Cellular studies of patient's-derived skin fibroblasts revealed a normal PIK3C2A protein level but a defective enzyme. Ciliary and cellular phenotype studies showed in the patient's cells impaired cilia formation and function as well as a reduced proliferative capacity. This study expands the clinical and mutational spectrum of PIK3C2A-related syndrome.</p>","PeriodicalId":10354,"journal":{"name":"Clinical Genetics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}