Exploring <i>IDH1</i> and <i>IDH2</i> Mutations in Paediatric Medulloblastoma

Fadul, Motaz; Baeesa, Saleh; Alkhotani, Alaa; Fathaddin, Amany A.; Lary, Ahmed I.; Addass, Bassam; Alsinani, Taghreed; Bamaga, Ahmed; Albeshri, Ahmad; Karami, Mohammed M.; Abutalib, Mohammed A.; Kurdi, Maher

doi:10.14712/fb2025071020073

Fol. Biol. 2025, 71, 73-78

https://doi.org/10.14712/fb2025071020073

Exploring IDH1 and IDH2 Mutations in Paediatric Medulloblastoma

Motaz Fadul¹

, Saleh Baeesa², Alaa Alkhotani³, Amany A. Fathaddin⁴, Ahmed I. Lary⁵, Bassam Addass⁶, Taghreed Alsinani⁷, Ahmed Bamaga⁸, Ahmad Albeshri⁵, Mohammed M. Karami⁹, Mohammed A. Abutalib¹⁰, Maher Kurdi¹

¹Department of Pathology, Faculty of Medicine, King Abdulaziz University, Rabigh, Saudi Arabia
²Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Prince Saud Al Faisal Street, Jeddah, Saudi Arabia
³Department of Pathology, College of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
⁴Department of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
⁵Section of Neurosurgery, Department of Surgery, King Abdulaziz Medical City, Makkah Road, Jeddah, Saudi Arabia
⁶Department of Surgery, Faculty of Medicine, King Abdulaziz University, Abdullah Suleiman Street, Jeddah, Saudi Arabia
⁷Department of Neurosurgery, King Fahad General Hospital, Jeddah, Saudi Arabia
⁸Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Abdullah Suleiman Street, Jeddah, Saudi Arabia
⁹Department of Clinical Physiology, Faculty of Medicine, King Abdulaziz University, Abdullah Suleiman Street, Jeddah, Saudi Arabia
¹⁰Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, Makkah Road, Jeddah, Saudi Arabia

Received January 2025
Accepted April 2025

Medulloblastoma (MB) in children is associated with distinct molecular subgroups, reflecting substantial biological heterogeneity. The presence of isocitrate dehydrogenase 1 (IDH1) and IDH2 mutations in paediatric MB has been rarely reported and not routinely investigated. Our study included 23 samples from paediatric patients diagnosed with MB. Hotspot alterations at codons IDH1 R132 and IDH2 R172 were examined using Sanger sequencing following polymerase chain reaction (PCR). The mean age of the patients was 10 years (SD: 4.25), comprising 17 males and 6 females. All cases exhibited classical histological features of MB. β-Catenin expression was observed in four cases (17.4 %), while 19 cases (82.6 %) showed no expression. No statistically significant differences in progression-free survival (PFS) were found between MBs with positive or negative β-catenin expression (P = 0.6). Radiotherapy alone was administered to four patients (17.4 %), while 19 patients (82.6 %) received combined radiotherapy and chemotherapy. The median PFS was 383 days (1 year and 18 days). IDH1 R132 or IDH2 R172 hotspot mutations were not detected in any of the samples. The absence of IDH1 or IDH2 mutations in paediatric MB may be attributed to differences in mutational profiles and cellular origins in childhood MB, despite its histomolecular similarities with adult MB.

Supplementary materials - Figures: Fig. 1, Fig. 2