RESUMEN
BACKGROUND: Familial cerebral cavernous malformations (CCM) are among the most common vascular malformations of the central nervous system (CNS) and are linked to mutations on the specific genes CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10. We present the first report in the literature of a pharmaco-resistant epileptic patient harboring co-occurring pathogenic mutations within CCM2/MGC4607 and CCM1/KRIT1. CASE DESCRIPTION: A 51-year-old patient first presented at age of 33 years with episodes of seizures. Magnetic resonance imaging including a susceptibility-weighted imaging sequence had shown multiple cerebral cavernous malformation lesions. She had partial response of symptoms and remained in routine follow-up needing progressive pharmacological improvement. Direct sequencing allowed the detection of 1 nonsense pathogenic mutation in CCM2/MGC4607 (c.118C>T; p.Arg40Ter) and 1 unclassified frameshift insertion variant in CCM1/KRIT1 (c.1687_1688insT; p.Tyr563LeufsTer5). CONCLUSIONS: Although the CCM2/MGC460 variant seems to be the major contributor for the patient's CCM phenotype, the mutated CCM1/KRIT1 seems to act as a booster to CCM overall pathogenicity.
Asunto(s)
Proteínas Portadoras/genética , Hemangioma Cavernoso del Sistema Nervioso Central/genética , Proteína KRIT1/genética , Epilepsia Refractaria/etiología , Hemangioma Cavernoso del Sistema Nervioso Central/complicaciones , Humanos , Imagen por Resonancia Magnética , Persona de Mediana EdadRESUMEN
BACKGROUND: Cerebral cavernous malformations (CCMs) are vascular capillary anomalies with a dysfunctional endothelial adherent junction profile, depicting hemorrhage and epilepsy as the main clinical features. With the advent of an increasingly personalized medicine, better comprehension of genetic mechanisms behind CCM represents an important key in the management of the patients and risk rating in relatives. In this context, genetic factors that might influence clinical expressiveness of CCM need to be identified. CASE DESCRIPTION: A 33-year-old woman harboring multiple CCM lesions with a CCM1 mutational profile already being treated conservatively for a right mesial temporal lobe CCM presented with refractory seizures. Magnetic resonance imaging showed no bleeding in the lesion, and the patient was submitted to complete resection of the CCM. Histopathology of the CCM samples depicted an extensive inflammatory reaction and colocalization of CD20+ and CD68+ cells. Genetic analyses of the patient and her mother demonstrated a novel CCM1 (KRIT1) frameshift mutation (c.1661_1662insT; p.Leu554PhefsTer14). Furthermore, variants in CD14 (rs778588), TLR-4 (rs10759930), SOD2 (rs4880), APEX1 (rs1130409), and OGG1 (rs1052133), known as polymorphisms related to disease aggressiveness, were detected in the patient and not in her oligosymptomatic mother harboring the same CCM1 mutation. CONCLUSIONS: Heterogeneity of clinical manifestations among individuals with familial CCM with the same genotype adds mechanistic involvement of modifier factors as phenotypic markers. We describe a novel CCM1/KRIT1 familial mutation in which the coexistence of genetic variants in inflammation and oxidative stress may be related to variable expressiveness of the disease.