Identification of a point mutation in factor XIII A subunit deficiency.

Oligonucleotide primers have been designed for the amplification of all 15 exons of the human coagulation factor XIII A subunit gene. Each exon and its intron flanking regions has been amplified and sequenced from a patient with severe A subunit deficiency. A single G to A transition in the last base of exon 14 has been identified in the homozygous proband and in his heterozygous parents. The mutation would result in the substitution 681 Arg to His in the mature protein product. However, because the mutation is at a splice junction, the deficiency may result from a defect in pre-messenger RNA splicing.