title: Synergistic effect of factor VII gene polymorphisms causing mild factor VII deficiency in a case of severe factor X deficiency.
abstract: Congenital combined deficiency of coagulation factors VII and X are mainly attributed to large deletions involving both the genes in chromosome 13 or occasionally due to the coincidental occurrence of independently occurring mutations. We report the molecular basis of congenital combined deficiency of factors VII and X in a 6-year-old female child. Direct DNA sequencing of both factor VII (F7) and factor X (F10) genes showed a novel homozygous missense mutation p.Cys90Tyr (c.307G>A) in exon 4 of F10. No mutations were detected in F7; however, the patient was homozygous for three polymorphic alleles known to be associated with reduced factor VII levels. The present case illustrates the synergistic effect of multiple polymorphisms resulting in phenotypic factor VII deficiency in the absence of a pathogenic mutation.
authors.affiliation: Department of Haemostasis and Thrombosis, National Institute of Immunohaematology (ICMR), Mumbai, India.
authors.forename: Rutuja
authors.initials: R
authors.lastname: Deshpande
authors.forename: Kanjaksha
authors.initials: K
authors.lastname: Ghosh
authors.forename: Shrimati
authors.initials: S
authors.lastname: Shetty
mesh_terms: D002648:Child; D005167:Factor VII / Q000235:genetics*; D005168:Factor VII Deficiency / Q000235:genetics*; D005171:Factor X Deficiency / Q000235:genetics*; D005260:Female; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic
chemical_list: D005167:Factor VII