OBJECTIVETo study the effect of CCM1 gene mutations in Chinese patients with intracranial cavernous angiomas(ICCA).

METHODSTwenty-one ICCA patients confirmed by pathology after operations in hospital from June 2002 to Feb.2003 and 15 healthy individuals as contrast were recruited. The peripheral venous blood samples of all the individuals were collected, and then DNA was extracted from the blood samples followed by amplification of exon 12 and some of its intron sequence using PCR. After purification, the PCR products were directly sequenced by ABI PRISM377 sequencing instrument.

RESULTSThree mutations of CCM1 gene were found in 5 patients and reported firstly. There existed a missense mutation of 1172C-->T in exon 12 in 5 patients, which led the No.391 amino acid of KRIT1 protein, serine, to phenyalanine. There existed a missense mutation of 1160A-->C in one patient, which led the No.387 amino acid, glutamine, to proline. Another mutation was an intronic mutation of IVS12-4C-->T in 4 patients. In contrast no mutations were found.

CONCLUSIONThe authors firstly report that mutations of CCM1 gene in exon 12 also exist in Chinese ICCA patients and those mutations are related with the occurring of ICCA.

Adolescent ; Adult ; Brain Neoplasms ; genetics ; Exons ; Female ; Hemangioma, Cavernous ; genetics ; Humans ; KRIT1 Protein ; Male ; Microtubule-Associated Proteins ; biosynthesis ; genetics ; Middle Aged ; Mutation ; Proto-Oncogene Proteins ; biosynthesis ; genetics

OBJECTIVETo detect the mutations of Krit-1 gene that cause familial cerebral cavernous malformation (CCM) in the Han ethnic origin.

METHODSThe subjects were hospitalized in the Department of Neurosurgery, Tiantan Hospital affiliated to Capital University of Medical Sciences. Two families (A and B) and 8 apparently sporadic individuals affected with CCM were screened for mutations of Krit-1 gene. Members of the family CCM have a wide range in age of onset with seizures, headaches and skin lesions. The gene was screened by PCR amplification of 16 exons and mutation was detected by direct sequencing.

RESULTSIn family A samples, analysis of the Krit-1 gene revealed a new point mutation in exon 14 [a heterozygous C to G transition at nucleotide 1 289 (counting from the start codon or nt 2 308 counting from the first nt of the mRNA, aligned according to Gene Bank AF388384)] which predicts the substitution of a premature termination codon for Serine at codon 430 (S430X), belonging a nonsense point mutation. No mutation was identified in one of family A members as well as in any of the sporadic individuals with the exception of a single nucleotide polymorphism.

CONCLUSIONSReport the first family in the Han with CCM having a novel mutation in the CCM1 gene on the continent of Asia. The newly identified mutation creates a premature termination codon and is predicted to produce a truncated Krev1 interaction-trapped 1 protein, KRIT1. This result allows efficient presymptomatic molecular diagnosis.

Adult ; Base Sequence ; Child ; Child, Preschool ; Female ; Hemangioma, Cavernous, Central Nervous System ; genetics ; pathology ; Humans ; KRIT1 Protein ; Male ; Microtubule-Associated Proteins ; genetics ; Middle Aged ; Molecular Sequence Data ; Mutation ; Proto-Oncogene Proteins ; genetics

BACKGROUNDFamilial cerebral cavernous malformations (CCMs), characterized by hemorrhagic stroke, recurrent headache and epilepsy, are congenital vascular anomalies of the central nervous system. Familial CCMs is an autosomal dominant inherited disorder and three CCM genes have been identified. We report a Chinese family with CCMs and intend to explore clinical, pathological, magnetic resonance imaging (MRI) features and pathogenic gene mutation of this family.

METHODSTotally 25 family members underwent brain MRI examination and clinical check. Two patients with surgical indications had surgical treatment and the specimens were subjected to histopathological and microstructural examination. In addition, polymerase chain reaction (PCR) and direct sequencing were performed with genomic DNA extracted from 25 family members' blood samples for mutation detection.

RESULTSBrain MRI identified abnormal results in seven family members. All of them had multiple intracranial lesions and four cases had skin cavernous hemangioma. T2-weighted sequence showed that the lesions were typically characterized by an area of mixed signal intensity. Gradient-echo (GRE) sequence was more sensitive to find micro-cavernous hemangiomas. There was a wide range in the clinical manifestations as well as the age of onset in the family. The youngest patient was an 8-year-old boy with least intracranial lesions. Histopathological and microstructural examination showed that CCMs were typically discrete multi-sublobes of berry-like lesions, with hemorrhage in various stages of illness evolution. They were formed by abnormally enlarged sinusoids and the thin basement membranes. A novel T deletion mutation in exon 14 of CCM1 gene was identified by mutation detection in the seven patients. But unaffected members and healthy controls did not carry this mutation.

CONCLUSIONSThe clinical manifestations were heterogenic within this family. We identified a novel mutation (c.1396delT) was the disease-causing mutation for this family and extended the mutational spectrum of CCMs.

Adult ; Animals ; Female ; Hemangioma, Cavernous, Central Nervous System ; diagnosis ; genetics ; Humans ; KRIT1 Protein ; Magnetic Resonance Imaging ; Male ; Microtubule-Associated Proteins ; genetics ; Middle Aged ; Mutation ; Pedigree ; Proto-Oncogene Proteins ; genetics