Elena Chinni1, Giovanni Tiscia1, Giovanni Favuzzi1, Filomena Cappucci1, Giuseppe Malcangi2, Rossana Bagna3, Claudia Izzi4, Domenica Rizzi5, Valerio De Stefano6, Elvira Grandone1. 1. Atherosclerosis and Thrombosis Unit, Fondazione IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (Foggia), Italy. 2. Department of Interdisciplinary Medicine, University of Bari, Bari, Italy. 3. Neonatology and Neonatal Intensive Care Unit, University Hospital, "Città della Salute e della Scienza", Turin, Italy. 4. Department of Obstetrics and Gynaecology, University of Brescia, Brescia, Italy. 5. Department of Paediatric and Neonatal Pathology, Marche Nord Hospital, Pesaro, Italy. 6. Institute of Haematology, Catholic University, Rome, Italy.
Abstract
BACKGROUND: Congenital fibrinogen disorders are caused by variants occurring within the fibrinogen gene cluster. We describe ten subjects with disease-causative variants, adding information on such disorders. MATERIALS AND METHODS: Ten subjects were referred to our Centre because of likely hypo/dysfibrinogenaemia. We evaluated the function and quantity of fibrinogen, using Clauss and immunoreactive assays, and performed genetic investigations by direct sequencing of alpha, beta and gamma chain-encoding genes. Mutations were analysed using SIFT and Polyphen-2 algorithms. RESULTS: We identified one afibrinogenaemic patient (alpha p.Arg178* homozygote) with bleeding/thrombotic events, three heterozygous patients with hypo/dysfibrinogenaemia (gamma p.Thr47ILeu combined with beta IVS7+1G>T; beta p.Cys95Ser; beta p.Arg196Cys) referred for bleeding or thrombotic episodes and six heterozygous subjects with hypofibrinogenaemia (alpha p.Glu41Lys; gamma p.Gly191Val; beta p.Gly288Ser; gamma p.His333Arg; gamma p.Asp342Glu and p.343-344 duplication; gamma p.Asp356Val), of whom four were symptomatic. Five novel missense changes and one novel duplication variant were found, all in hypofibrinogenaemic subjects: p.Glu41Lys (SIFT score 0, Polyphen-2 score 0.986) was identified in a woman with bleeding after major orthopaedic surgery; p.Gly191Val (SIFT score 0.02, Polyphen-2 score 1) in an asymptomatic woman; p.His333Arg (SIFT score 0, Polyphen-2 score 1) in a woman with a post-partum haemorrhage; and p.Asp342Glu (SIFT score 0.23, Polyphen-2 score 0.931); and an Asn-343 and Asp-344 duplication in a child who developed a haematoma following a fall. DISCUSSION: All but one of the novel mutations were in symptomatic subjects and are predicted to be deleterious. Our findings shed more light on genotype-phenotype relationships in congenital fibrinogen disorders.
BACKGROUND:Congenital fibrinogen disorders are caused by variants occurring within the fibrinogen gene cluster. We describe ten subjects with disease-causative variants, adding information on such disorders. MATERIALS AND METHODS: Ten subjects were referred to our Centre because of likely hypo/dysfibrinogenaemia. We evaluated the function and quantity of fibrinogen, using Clauss and immunoreactive assays, and performed genetic investigations by direct sequencing of alpha, beta and gamma chain-encoding genes. Mutations were analysed using SIFT and Polyphen-2 algorithms. RESULTS: We identified one afibrinogenaemic patient (alpha p.Arg178* homozygote) with bleeding/thrombotic events, three heterozygous patients with hypo/dysfibrinogenaemia (gamma p.Thr47ILeu combined with beta IVS7+1G>T; beta p.Cys95Ser; beta p.Arg196Cys) referred for bleeding or thrombotic episodes and six heterozygous subjects with hypofibrinogenaemia (alpha p.Glu41Lys; gamma p.Gly191Val; beta p.Gly288Ser; gamma p.His333Arg; gamma p.Asp342Glu and p.343-344 duplication; gamma p.Asp356Val), of whom four were symptomatic. Five novel missense changes and one novel duplication variant were found, all in hypofibrinogenaemic subjects: p.Glu41Lys (SIFT score 0, Polyphen-2 score 0.986) was identified in a woman with bleeding after major orthopaedic surgery; p.Gly191Val (SIFT score 0.02, Polyphen-2 score 1) in an asymptomatic woman; p.His333Arg (SIFT score 0, Polyphen-2 score 1) in a woman with a post-partum haemorrhage; and p.Asp342Glu (SIFT score 0.23, Polyphen-2 score 0.931); and an Asn-343 and Asp-344 duplication in a child who developed a haematoma following a fall. DISCUSSION: All but one of the novel mutations were in symptomatic subjects and are predicted to be deleterious. Our findings shed more light on genotype-phenotype relationships in congenital fibrinogen disorders.
Authors: M Margaglione; V Brancaccio; N Giuliani; G D'Andrea; G Cappucci; L Iannaccone; G Vecchione; E Grandone; G Di Minno Journal: Ann Intern Med Date: 1998-07-15 Impact factor: 25.391