Mapping, Candidate Cloning Of A Novel Disease Gene For BFIC And The Mutation Analysis Of KCNQ3 Gene In BFNC Families

Part â…  Mapping of a novel locus for benign familial infantile convulsions on chromosome 1p36.12-35.1Benign familial infantile convulsions (BFIC) is a rare epileptic syndrome with the mode of autosomal dominant inheritance. BFIC is characterized by afebrile unprovoked convulsions which typically start from month 3 to 12 and remit spontaneously after 2 to 5 years old. The neuroradiological and plasma biochemical examinations and interictal electroencephalogram (EEG) of the patients are usually normal. In the majority of affected individuals, longterm development is normal. By genetic linkage analysis, three gene loci for BFIC have been mapped on chromosome 19q12-13.1, 16p12-q12 and 2q24 respectively. Until now, no gene responsible for BFIC has been identified. A large Chinese family with BFIC was found in Hunan province of China. All of the affected individuals had the typical BFIC phenotype. By linkage analysis, we excluded the linkage to the three known gene loci and the relative gene loci of BFIC. The result of linkage analysis showed that a novel locus for BFIC exists. Then we performed genome-wide screening and linkage analysis in the family. A maximum two-point LOD score of 3.14 for D1S2674 at recombination of 0 was identified. Haplotype analysis mapped the novel locus on chromosome 1p36.12-35.1, over 12.4cM interval between markers D1S2864 and D1S2830.