Genotype-phenotype correlations in cerebral cavernous malformations patients.

Area of Science:

• Genetics
• Neurology
• Medical Research

Background:

• Cerebral cavernous malformations (CCMs) are vascular malformations in the brain.
• Genetic mutations in CCM1, CCM2, and CCM3 genes are known causes of CCMs.
• Understanding genotype-phenotype correlations is crucial for patient management.

Purpose of the Study:

• To compare the clinical characteristics of patients with mutations in CCM1, CCM2, and CCM3 genes.
• To identify potential differences in disease presentation, progression, and genetic penetrance among the three CCM gene mutation types.

Main Methods:

• A cohort of 163 families with cerebral cavernous malformations underwent clinical and molecular analysis.
• Deleterious mutations were identified in 128 probands, leading to the identification of 333 mutation carriers (238 CCM1, 67 CCM2, 28 CCM3).
• Clinical data, including age of onset, lesion load on imaging, and family history, were analyzed and compared across mutation groups.

Main Results:

• Ninety-four percent of probands with affected relatives had a mutation, versus 57% of those without affected relatives.
• CCM3 families had fewer affected individuals per family and a higher proportion of patients with symptom onset before age 15.
• Cerebral hemorrhage was the most common initial presentation in CCM3 patients; lesion progression with age differed between CCM1 and CCM2.

Conclusions:

• CCM3 mutations are associated with reduced family penetrance and an increased risk of early-onset cerebral hemorrhage.
• The number of gradient-echo sequence lesions increases more rapidly with age in CCM1 compared to CCM2 patients.
• Despite overlapping clinical features, distinct genetic profiles of CCM1, CCM2, and CCM3 influence disease presentation and progression.