Since 1960 when DUCKERT et al., observed a familial bleeding disorder due to a deficiency of Factor XIII, 21 cases, involving 8 families have been reported.
We have diagnosed Factor XIII deficiency in a 6-year-old boy with mild bleeding manifestations and studied the concentration of Factor XIII in his family and in normal infants.
An assay technique has been devised utilizing the patient's plasma as deficient substrate, with normal pooled plasma as the standard. Dilutions of plasma from 1:300 to 1:1000 yield a straight line with a steep slope when plotted on log-log paper against clot liquifaction time in minutes; it is reproducible. In vivo survival studies after transfusing the patient show a halflife of 5–7 days in agreement with other reports. Factor XIII was assayed in 50 infants and children from birth to 20 months of age as follows: newborn (10)-average 63 %, range 50–76 %; 0–5 months (10)-average 115 %, range 100–160%; 6–9 months (10)-average 90%, range 80–110%; 10–15 months (10)-average 90%, range 72–118%; and 16–20 months (10)-average 94%, range 70–120%. Our adult range was 90 to 136%. After the newborn period, Factor XIII is present in normal adult concentrations. Our data suggest a more rapid rise to normal and no evidence of the fall at ages 6–9 months as reported by KÜNZER (Ann. Pediat. 204: 232 ).
Family Factor XIII levels were: father 75%, mother 48 %, 2 sisters 57 % and 48 % and brother 42 %. This tends to confirm the autosomal recessive inheritance of Factor XIII deficiency. (SPR)