title: Incomplete EcoRI digestion may lead to false diagnosis of fragile X syndrome.
abstract: Molecular diagnosis of fragile X syndrome is usually performed using Southern blot analysis of DNA digested with EcoRI. In the course of diagnostic studies, we observed that a specific EcoRI restriction site in the fragile X gene (FMR1) is sometimes refractory to digestion, generating additional fragments on a Southern blot suggestive of a full mutation in FMR1. This may lead to a false-positive diagnosis of fragile X syndrome. Such additional bands are avoided by the use of HindIII instead of EcoRI. Therefore, we recommend the use of HindIII for the molecular diagnosis of fragile X syndrome.
authors.affiliation: Department of Medical Genetics, University of Antwerp, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Storm
authors.forename: I
authors.initials: I
authors.lastname: Handig
authors.forename: E
authors.initials: E
authors.lastname: Reyniers
authors.forename: B A
authors.initials: BA
authors.lastname: Oostra
authors.forename: R F
authors.initials: RF
authors.lastname: Kooy
authors.forename: P J
authors.initials: PJ
authors.lastname: Willems
mesh_terms: D015139:Blotting, Southern / Q000379:methods; D015246:Deoxyribonuclease EcoRI / Q000378:metabolism*; D015247:Deoxyribonuclease HindIII / Q000378:metabolism; D005189:False Positive Reactions; D005600:Fragile X Syndrome / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D009154:Mutation; D015183:Restriction Mapping / Q000379:methods
chemical_list: D015246:Deoxyribonuclease EcoRI; D015247:Deoxyribonuclease HindIII