Variable expression of cerebral cavernous malformations in carriers of a premature termination codon in exon 17 of the Krit1 gene.

Autor: Lucas, Miguel, Costa, Alzenire F., García-Moreno, José M., Solano, Francisca, Gamero, Miguel A., Izquierdo, Guillermo
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Zdroj: BMC Neurology; 2003, Vol. 3, p5-6, 6p, 3 Diagrams, 1 Chart
Abstrakt: Background: Cerebral cavernous malformations (CCM) present as either sporadic or autosomal dominant conditions with incomplete penetrance of symptoms. Differences in genetic and environmental factors might be minimized among first-degree relatives. We therefore studied clinical expression in a family with several affected members. Methods: We studied a three-generation family with the onset of CCM as a cerebral haemorrhage in the younger (four-year-old) sibling. Identification and enumeration of CCMs were performed in T2-weighted or gradient-echo MRIs of the whole brains. Genetic analysis comprised SCCP, sequencing and restriction polymorphism of the Krit1 gene in the proband and at risk relatives. Results: The phenotypes of cerebral cavernous malformations (CCMs) in carriers of Krit1 mutations were very variable. We identified a novel frameshift mutation caused by a 1902A insertion in exon 17 of the Krit1 gene, which leads to a premature TAA triplet and predicts the truncating phenotype Y634X. A very striking finding was the absence of both clinical symptoms and CCMs in the eldest sibling harbouring the 1902insA. Conclusions: Patients in this family, harbouring the same mutation, illustrate the very variable clinical and radiological expression of a Krit1 mutation. The early and critical onset in the proband contrasts with minor clinical findings in affected relatives. This consideration is important in genetic counselling. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index