title: Diagnosis of two related carriers of severe haemophilia B with no family history.
abstract: Haemophilia B is an X-linked disease affecting 1 in 30 000 males. Carrier diagnosis is usually carried out only in female relatives of haemophilic males, and the likelihood of discovering a carrier without a haemophilic male is very low. In this report we present the cases of two related women without a family history of haemophilia who were diagnosed as haemophilia B carriers. Following a minor haemorrhage in the proband, she and her mother were thought to be haemophilia B carriers because of a low factor IX level (16 and 23 IU dL-1, respectively; normal values >50 IU dL-1). The non-sense mutation C31118T, which is associated with severe haemophilia B, was detected in both women. This allowed us to diagnose them as being definite carriers of severe haemophilia B and give appropriate genetic counselling.
authors.affiliation: Unidad de Coagulopatías Congénitas, Hospital 'La Fe', Valencia, Spain. jlorenzoh@aehh.org
authors.forename: J I
authors.initials: JI
authors.lastname: Lorenzo
authors.forename: P
authors.initials: P
authors.lastname: Casaña
authors.forename: C
authors.initials: C
authors.lastname: Espinós
authors.forename: R
authors.initials: R
authors.lastname: Ferrer
authors.forename: J A
authors.initials: JA
authors.lastname: Aznar
mesh_terms: D000328:Adult; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D005164:Factor IX / Q000378:metabolism; D005192:Family Health; D005260:Female; D006580:Genetic Carrier Screening; D002836:Hemophilia B / Q000175:diagnosis* / Q000235:genetics*; D006470:Hemorrhage / Q000209:etiology / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D010375:Pedigree; D017354:Point Mutation
chemical_list: D018389:Codon, Nonsense; D005164:Factor IX