Mutation prevalence of cerebral cavernous malformation genes in Spanish patients.
OBJECTIVE
To study the molecular genetic and clinical features of cerebral cavernous malformations (CCM) in a cohort of Spanish patients.


METHODS
We analyzed the CCM1, CCM2, and CCM3 genes by MLPA and direct sequencing of exons and intronic boundaries in 94 familial forms and 41 sporadic cases of CCM patients of Spanish extraction. When available, RNA studies were performed seeking for alternative or cryptic splicing.


RESULTS
A total of 26 pathogenic mutations, 22 of which predict truncated proteins, were identified in 29 familial forms and in three sporadic cases. The repertoire includes six novel non-sense and frameshift mutations in CCM1 and CCM3. We also found four missense mutations, one of them located at the third NPXY motif of CCM1 and another one that leads to cryptic splicing of CCM1 exon 6. We found four genomic deletions with the loss of the whole CCM2 gene in one patient and a partial loss of CCM1and CCM2 genes in three other patients. Four families had mutations in CCM3. The results include a high frequency of intronic variants, although most of them localize out of consensus splicing sequences. The main symptoms associated to clinical debut consisted of cerebral haemorrhage, migraines and epileptic seizures. The rare co-occurrence of CCM with Noonan and Chiari syndromes and delayed menarche is reported.


CONCLUSIONS
Analysis of CCM genes by sequencing and MLPA has detected mutations in almost 35% of a Spanish cohort (36% of familial cases and 10% of sporadic patients). The results include 13 new mutations of CCM genes and the main clinical symptoms that deserves consideration in molecular diagnosis and genetic counselling of cerebral cavernous malformations.
Servicio de Biología Molecular, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain.
Rufino
R
Mondéjar
Servicio de Biología Molecular, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain.
Francisca
F
Solano
Servicio de Biología Molecular, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain.
Rocío
R
Rubio
Servicio de Biología Molecular, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain.
Mercedes
M
Delgado
Servicio de Neurología, Hospital Universitario de Alicante, Alicante, Spain.
Angel
A
Pérez-Sempere
Unidad de Dismorfología, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
Antonio
A
González-Meneses
Unidad de Genética, Hospital Universitario Vall d'Hebron, Barcelona, Spain.
Teresa
T
Vendrell
Servicio de Neurología, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain.
Guillermo
G
Izquierdo
Instituto de Biomedicina de Sevilla (IBiS)/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.
Amalia
A
Martinez-Mir
Servicio de Biología Molecular, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain.
Miguel
M
Lucas
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D005787:Gene Frequency; D020786:Hemangioma, Cavernous, Central Nervous System / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D000075927:KRIT1 Protein; D008565:Membrane Proteins / Q000235:genetics*; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D017384:Sequence Deletion; D013030:Spain; D055815:Young Adult
D051017:Apoptosis Regulatory Proteins; C502544:CCM2 protein, human; D002352:Carrier Proteins; D018389:Codon, Nonsense; D000075927:KRIT1 Protein; C107928:KRIT1 protein, human; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; C495390:PDCD10 protein, human; D011518:Proto-Oncogene Proteins