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Background A large family with autosomal dominant nocturnal frontal lobe epilepsy from the south of Spain was studied. The clinical appearance of the disease in this family, which included 28 members, of whom 11 were affected and 2 were obligate carriers, was identical to that previously described in an Australian family and a Norwegian family, in which mutations in exon 5 of theCHRNA4gene were found. Methods Following DNA extraction, the family was genotyped with 4 fluorescent markers flanking the locus to theCHRNA4gene on chromosome 20q13.3, and lod score computations were performed. The exon 5 of theCHRNA4gene was amplified between nucleotides 535 and 825 and polymerase chain reaction products were purified and sequenced directly. Results The same missense mutation as that found in the Australian family, C→T, which causes the replacement of a serine with phenylalanine in amino acid 252 in exon 5, was detected. This mutation segregated with the disorder in all 11 affected members, in the 2 obligate carriers, and in 1 asymptomatic sibling, and was not found in 1 spouse and 1 daughter. Neither of the 2 polymorphisms associated with this mutation in the Australian family were found, excluding a common ancestral haplotype for the 2 families. Conclusions These data confirm the clinical homogeneity in the phenotypic expression of autosomal dominant nocturnal frontal lobe epilepsy caused by mutation in theCHRNA4gene, and the pathogenic role of the Ser252Phe mutation in this disorder.

Estrogens play an important role in the genesis of experimental and human breast cancers1,2. Once established, the tumors are frequently hormone-dependent, i.e. they regress or stop growing if deprived of estrogen3. in humans, about one-third of advanced breast cancers are thus susceptible to remission with endocrine therapy4. Criteria for the selection of patients that will respond to hormonal treatment have been the subject of intense study during the last 2 decades5. On the molecular level this had led to the development of analytical tools for the study of steroid receptors and steroid-induced proteins.

A method is described to map contiguous epitopes recognized by monoclonal antibodies in the case when the cDNA for a protein has been cloned. The cDNA is inserted into an expression vector allowing its acellular transcription, followed by the translation of the resulting messenger RNA. C-terminally truncated species of the protein are either generated by cutting the cDNA with restriction enzymes or arise spontaneously through stops occurring during translation of the mRNA. If necessary, progressive digestion by Bal31 of the cDNA can be used to produce an array of polypeptides having different C-terminal lengths. Immunoprecipitation then allows determination of the shortest protein recognized by the monoclonal antibody and thus to define its site of action. This method has been applied to the study of a group of selected monoclonal antibodies among the 59 that have been prepared against the rabbit progesterone receptor. Four immunogenic domains were identified lying between amino acids 1-60, 101-110, 295-325 and 370-396. There were no antibodies directed against the DNA-binding or the steroid-binding regions of the receptor. This is probably due to the high degree of amino acid sequence conservation in these domains, observed when comparing receptors from different species. The antibodies cross-reacting with highest affinity for the human receptor interact with the first immunogenic domain (amino acids 1-60). The 79-kDa form (‘subunit A’) of the receptor was shown to lack the two more N-terminally localized immunogenic domains (amino acids 1-60 and 101-110). The 65-kDa form lacked, in addition, the domain localized between amino acids 295 and 325. These two forms of the receptor thus correspond to deletions of the N-terminal part of the protein.