Clinical Phenotype: Can Each RBD be Characterized in Terms of Typical Bleeding Features?
Patients affected by RBDs present with a wide range of clinical phenotypes – being asymptomatic at one end of the spectrum and suffering fatal cerebral nervous system bleeding at the other. As discussed above, heterozygous carriers of RDBs are usually asymptomatic or might present with mild bleeding manifestations. Therefore, the occurrence of severe spontaneous bleedings in RDB heterozygotes should prompt clinicians to rule out an additional hemostasis disorder. On the other hand, children homozygous for a RBD can be either asymptomatic or exhibit mild, moderate or severe bleeding. The bleeding tendency can first appear at any age, although the more severely affected patients may present with life-threatening hemorrhages within the first few days of birth.
Even when focusing on the severe forms of RBDs, no one bleeding feature definitively characterizes any one of the RBDs discussed in this review, although some may be more suggestive of a specific factor deficiency than others. First, nervous system bleeding occurring within the first few months of birth is more frequently associated with severe FII, FVII, FX and FXIII deficiencies than with severe FV deficiency or afibrinogenemia. Second, delayed umbilical stump bleeding is suggestive of FXIII deficiency (occurring in 80% of cases) or afibrinogenemia. Finally, hemarthrosis more frequently occurs in association with FV deficiency than with any other RBD. Among this group of clotting disorders, inherited FXI deficiency stands apart as it is most commonly an injury-related bleeding disorder. The main characteristics of each RBD are summarized in Table 1 .
Severe clinical features including spontaneous ICH, whilst being rare, do account for the mortality associated with this group of diseases. The incidence is estimated at 34, 21 and 7% in FXIII, FX and FVII deficiencies, respectively, with a high prevalence of consanguinity among the parents of affected newborns. Clinical presentation varies considerably between published case reports, irrespective of the deficient clotting factor. ICH can represent the first symptom, and can be observed as early as in the first few days following birth or later on in infancy after a normal prenatal period and delivery. However, signs of a congenital bleeding disorder, such as bleeding mucosae including epistaxis of varying degrees of severity and easy bruising, or more suggestively, soft tissue hematomas or umbilical stump bleeding, often occur in the weeks preceding a cerebral bleed.[13,14] Therefore, the presence of unexpected bleeding symptoms, especially if the parents are consanguineous, should prompt physicians to perform clotting tests. Equally important is the diagnosis of a congenital bleeding disorder, which should be considered in children with spontaneous ICHs, even in those who had no prior episode of extracerebral hemorrhage.
As mentioned previously, bleeding histories of children demonstrate marked differences to those of adults. For example, postsurgical bleeding, a classical symptom that is generally considered to be of value to bleeding histories, is not prevalent in pediatric patients since patients are often too young to have suffered any hemostatic challenge. Therefore, in pediatric cases, particular attention must be given to any provoked bleeding, for example, at the time of circumcision or umbilical cord bleeding.
Pediatr Health. 2010;4(2):209-217. © 2010 Future Medicine Ltd.
Cite this: Comprehensive Pediatric Care of Rare Bleeding Disorders - Medscape - Apr 01, 2010.