Identification of a new Leu354Pro mutation responsible for factor XIII deficiency

We report a new homozygous CTG-->tCCG (Leu-->Pro) mutation at codon 354 in the factor XIIIA gene of a patient suffering from FXIII deficiency. Leu354 lies in a pocket within the core domain of the FXIIIA molecule, with its si de chain pointing into the structure of the barrel 1 domain. Replacement of leucine with a proline residue gives rise to steric hindrance between the proline ring and the surrounding residues, and rearrangement of these resid ues would be necessary for proline to be accommodated at this position. Usi ng PCR-RFLP, we have demonstrated the absence of this mutation from 220 nor mal alleles. Together, these data suggest that Leu354Pro is likely to be th e disease-causing mutation in this factor XIII deficient family.