Genetic Screening of Pediatric Cavernous Malformations

Area of Science:

• Neuroscience
• Genetics
• Vascular Biology

Background:

• Cerebral cavernous malformations (CCMs) are vascular anomalies in the central nervous system.
• Mutations in CCM1, CCM2, and CCM3 genes are linked to familial and sporadic CCM cases.
• Understanding genetic underpinnings is crucial for diagnosis and counseling.

Purpose of the Study:

• To investigate the mutation spectrum of CCM1, CCM2, and CCM3 genes in a pediatric-predominant cohort.
• To determine the detection rate of pathogenic mutations in familial and sporadic CCM cases.
• To correlate genetic findings with clinical presentation, particularly hemorrhage risk.

Main Methods:

• Genetic screening of 31 patients, primarily pediatric, using multiplex ligation-dependent probe amplification (MLPA) and direct sequencing.
• Analysis focused on exons and intronic boundaries of CCM1, CCM2, and CCM3 genes.
• Identification and characterization of pathogenic mutations and novel variants.

Main Results:

• Pathogenic loss-of-function mutations were identified in 10 out of 31 patients (32%).
• Mutation detection rate was high in familial cases (75%), especially pediatric (85%).
• A novel CCM3 variant (c.130-131insT) was found in a pediatric sporadic case; cerebral hemorrhage was the primary symptom.

Conclusions:

• High penetrance of CCM gene mutations (85%) observed in familial pediatric cases.
• Genetic testing can enhance clinical and genetic counseling for CCM patients.
• CCMs in children carry a significant risk of cerebral hemorrhage.