{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,20]],"date-time":"2025-11-20T06:58:35Z","timestamp":1763621915451,"version":"3.45.0"},"reference-count":18,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,11,20]],"date-time":"2025-11-20T00:00:00Z","timestamp":1763596800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pediatr."],"abstract":"<jats:p>\n                    Pathogenic variants in the\n                    <jats:italic>PIK3CA<\/jats:italic>\n                    gene, which encodes the p110-\u03b1 catalytic subunit of the phosphoinositide 3-kinase (PI3K), are commonly associated with overgrowth syndromes and cancer. We report a patient with the point variant c.1030G&amp;gt;A p.(Val344Met) in the\n                    <jats:italic>PIK3CA<\/jats:italic>\n                    gene who presented shortly after birth with viral sepsis and and severe lymphopenia, followed by colonic perforations. Histopathology showed ulcerative necrotizing colitis with lymphatic vascular malformation. The patient subsequently developed hydrocephalus requiring a ventriculoperitoneal shunt, complicated by refractory ascites that resolved with acetazolamide therapy. Awareness of the potential disease spectrum through early molecular diagnosis, combined with a comprehensive immunologic evaluation, enabled individualized management via closer clinical monitoring and timely interventions to prevent and control neurological and infectious complications. This case highlights the phenotypic heterogeneity of\n                    <jats:italic>PIK3CA<\/jats:italic>\n                    pathogenic variants and the importance of early precision medicine in pediatric care.\n                  <\/jats:p>","DOI":"10.3389\/fped.2025.1650077","type":"journal-article","created":{"date-parts":[[2025,11,20]],"date-time":"2025-11-20T06:17:38Z","timestamp":1763619458000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Low lymphozyte pool, colon perforation and hydrocephalus as clinical features in an infant with a postzygotic PIK3CA variant"],"prefix":"10.3389","volume":"13","author":[{"given":"Ximena","family":"L\u00e9on-Lara","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sarina","family":"Ravens","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sandra","family":"von Hardenberg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bernd","family":"Auber","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anke K.","family":"Bergmann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Laura","family":"Ospina","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Florian","family":"Guthmann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christiane","family":"W\u00fcbbena","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jan","family":"Brechler","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J\u00fcrgen","family":"Weidemann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manuela F.","family":"Richter","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,11,20]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"575","DOI":"10.3389\/fimmu.2018.00575","article-title":"Molecular mechanisms of human disease mediated by oncogenic and primary immunodeficiency mutations in class IA phosphoinositide 3-kinases","volume":"9","author":"Dornan","year":"2018","journal-title":"Front Immunol"},{"key":"B2","doi-asserted-by":"publisher","first-page":"606","DOI":"10.1038\/nrg1879","article-title":"The evolution of phosphatidylinositol 3-kinases as regulators of growth and metabolism","volume":"7","author":"Engelman","year":"2006","journal-title":"Nat Rev Genet"},{"key":"B3","doi-asserted-by":"publisher","first-page":"856","DOI":"10.1016\/j.molmed.2018.08.003","article-title":"Cancer-Associated PIK3CA mutations in overgrowth 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