hemophilia a ( ha ) results from the partial or complete deficiency of functional factor viii ( fviii ) protein caused by a wide range of heterogeneous mutations in the factor 8 ( f8 ) gene . being an x - linked recessive disorder , females are generally not affected , although they can be carriers of this disorder . a classical female hemophilia is possible only when a carrier female marries a hemophilic male , of which there are only few reports in the literature.[24 ] few other reports of homozygous female ha are mainly due to de novo mutations in one or both the x chromosomes . blood was collected by peripheral venous puncture at a 1:10 volume ratio in 3.8% trisodium citrate . activated partial thromboplastin time ( aptt ) factor viii activity ( fviii : c ) of each sample was determined by one - stage aptt - based assay in a semiautomated coagulometer ( diagnostica stago , asnieres , france ) . plasma von willebrand factor antigen level ( vwf : ag ) was measured by enzyme - linked immunosorbent assay ( diagnostica stago ) . multiplex polymerase chain reactions spanning all the 26 exons were carried out and conformation - sensitive gel electrophoresis ( csge ) was used to screen the mutations . amplicons were run on a 12.5% gel ( acrylamide : 1 , 4-bis acroylyl piperazine 99:1 ) incorporating mild denaturants ( 10% ) ethylene glycol , 15% formamide and electrophoresed overnight at 80v dna sequencing was performed on both strands using the big dye terminator cycle sequencing v1.1 ready reaction kit and an automated abi dna sequencer ( applied biosystems , carlsbad , california . we report a case of homozygous female ha with moderate fviii deficiency ( moderate fviii deficiency 5.5% fviii : c , vwf : ag 120% ) , born of a 1 consanguineous marriage . she presented to our center with severe bleeding diathesis following delivery of her first child and a history of prolonged bleed from cuts and injuries . the mother ( a carrier of ha ) of the proband was married to a hemophilic who died of excessive bleeding in a road accident and was undiagnosed but his two brothers were diagnosed with moderate deficiency of ha ( f viii : c 4.8% and 5.7% ) . her two brothers were affected and the sister was found to be a carrier of ha . pedigree of an extensive family with classical female hemophilia a sequencing of this exon revealed a missense mutation corresponding to c.1315g > a , which results in the amino acid substitution corresponding to p.gly420ser that fits well with the clinical manifestation of the patient [ figure 2 ] . the mother was shown to be a heterozygous carrier of the mutation , while the two affected brothers , uncles and nephews also showed the same mutation . they were found to be cross - reacting material ( crm ) negative [ table 1 ] . a missense mutation c.1315g > a ( p.gly420ser ) in moderate hemophilia a genotypic  phenotypic correlation it was inferred that the father of this index case was also affected and carried the same mutation as that of the index case . the mutation has earlier been reported to be associated with moderate and severe ha , causing polarity change in the protein coil thus influencing the secondary structure of the protein . female carriers of ha normally do not exhibit a moderate to severe phenotypic expression of the disease . however , a number of other pathophysiological mechanisms may account for the phenotypic expression of very low fviii : c levels in females . these include ( i ) skewed inactivation of the x chromosome leading to predominant expression of the mutated allele as a result of a preferential inactivation of the x chromosome with the wild - type f8 gene , ( ii ) turner syndrome , ( iii ) translocation or ( iv ) males with a female phenotype due to mutation in the sex - determining region y ( sry ) gene on the y chromosome , i.e. swyer syndrome combined with a mutation in the f8 gene . in the present report , we have presented homozygosity of the f8 gene mutation resulting in clinical manifestation of ha in a female . in india , as consanguineous marriages are very common in certain communities ( up to 30% ) , the likelihood of encountering female hemophilia is higher , although this is the first case of ha encountered out of 1600 hemophilia families registered in our comprehensive haemophilia care center . genetic diagnosis in such cases is not necessary as all the male children will be affected and daughters are obligatory carriers .
background : hemophilia a ( ha ) , being an x - linked recessive disorder , females are rarely affected , although they can be carriers.aims:to study the mutation in f8 gene in an extended family with a homozygous female ha.materials and methods : all the seven affected members ( six males and one female ) were initially screened by conformation sensitive gel electrophoresis ( csge ) and direct dna sequencing.results:a homozygous missense mutation c.1315g > a ( p.gly420ser ) was identified in exon 9 of f8 gene in homozygous state in the affected female born of 1 consanguinous marriage and in all the affected male members of the family . 
 her factor viii levels was found to be 5.5% , vwf : ag 120%.conclusion : in india , as consanguineous marriages are very common in certain communities ( up to 30% ) , the likelihood of encountering female hemophilia is higher , although this is the first case of ha out of 1600 hemophilia families registered in our comprehensive haemophilia care center . 
 genetic diagnosis in such cases is not necessary as all the male children will be affected and daughters obligatory carriers .