As standard clotting tests are normal in cases with F XIII deficiency, due to the clotting end point being unaffected by the absence of F XIII, their clinical diagnosis becomes highly critical. However, if noted from the quality of clot, which is abnormal, such entity will easily be identified and plenty of strategies can be arranged to prevent its complications. In these circumstances the diagnosis will not be missed when the quality of clotting is assessed (
6). Standard clot solubility test is the screening test for F XIII deficiency in the urea and in some instances monochloroacetic acid measure (
12). A definite diagnosis is then made on the basis of functional and immunological assays (
7). For many years, whole blood, fresh frozen plasma or a placental F XIII concentrate have been used successfully in the treatment of F XIII deficiency. More recently, a plasma- derived pasteurized concentrate marketed under the name of Fibrogammin-P (Centeon Pharma GmbH, Marburg, Germany) has also become available on the market. Since very low levels of F XIII in plasma are sufficient to control bleeding, and as the in vivo half-life of F XIII is long (11 - 14 days) after infusion, prophylaxis is considered as a simple and practical step (
13). It is believed that any level of FXIII within 3 to 10% of the mean value in the normal population, i.e. 0.03 - 0.1 IU/mL, is sufficient to prevent spontaneous hemorrhage (
14-
17). Although rare, F XIII deficiency is a remarkable disorder because of its serious bleeding manifestations. In particular, the majority of the cases have life-threatening symptoms early in life. However, there are reports of cases in the literature with problems that had not been detected until a later step and following severe bleeding as a sequel of a minor surgery (
7).
The current patient was not diagnosed as an F XIII deficient case until the age of five years, despite prolonged umbilical bleeding during her neonatal period similar to the reported case by Anwar et al. (
6). However, the key to early diagnosis is considered as the presence of serious bleeding manifestations, especially intracranial hemorrhage, which can easily be prevented if noted on time through prophylactic F XIII concentrate administration. Vigorous replacement therapy seems to be helpful in controlling the tendency of miscarriage in F XIII deficient pregnant females (
6).
Decreased level of RBC*, HGB** and HCT*** may be due to excessive amount of blood loss after the first severe bleeding episode. A positive history of umbilical hemorrhage together with the clinical symptoms, led the hematologist to perform the F XIII assessment in order to confirm the diagnosis. As mentioned earlier, F XIII deficiency is an autosomal recessive disorder. This indicates that both parents must be carriers of the defective gene to pass it on to their children. In this patient, the negative familial and/or consanguinity history may attribute the disorder to mutations in F XIII type A gene. Recent studies have proved that such mutations are the most common causes of F XIII deficiency (
15). Unlike this scenario, the case reported by Killick et al. (
16) highlighted the importance of seeking familial history of bleeding disorders prior to surgery in the neonatal period, particularly if the parents are consanguineous.
Whole blood, fresh frozen plasma, stored plasma and cryoprecipitate are considered as the adequate sources of F XIII and have commonly been used successfully in the treatment of F XIII deficiency in the recent years (6). Fibrogammin-P is a recently available F XIII concentrate and is derived from the plasma of healthy donors. The methods of preparation of Fibrogammin-P have been described by Karges and Metzner (
17). Patients are given 1000 units of concentrate every five to six weeks. A vial of concentrate contains 250 units, which is dissolved in 4 mL of water. Therefore, the patient receives 16 mL of the dissolved concentrate, intravenously for one to two minutes. This raises the plasma F XIII activity level to about 30-35% of average normal levels while the process of coagulation remains normal for five to six weeks.
As young individuals are more active and therefore more prone to injury than adults, it has been recommended that they should receive the concentrate at four-week intervals. However, Miloszewski and Losowsky (
18) found six-week intervals as adequate in the prevention of hemorrhage in their patients. Although fibrogammin-P is the product of choice, due to its unavailability, cryoprecipitate (containing F I, F VIII, F XIII and Von Willebrand Factor) was infused to control bleeding. In order to control bleeding before the dental procedure Factor XIII 10 - 20 U/Kg concentrate was used as prophylactic therapy every four to six weeks in order to have adequate plasma level (
19-
22). As routine, it is recommended for all F XIII-deficient patients to receive prophylactic treatment immediately after confirmation of the diagnosis due to high risk of intracranial hemorrhage. From the dental management point, since hemorrhagic diseases are usually diagnosed at an early childhood stage, child dental clinics are possibly the first to see the manifestation of these disorders. In such cases, an accurate work up and correct laboratory tests and diagnosis could not only control and prevent the hemorrhage but also most of the dental procedures could be delivered to such individuals in a very safe and normal manner, similar to the case of this report.