Deficiencies in Factors XIII and IX
There are ten clotting factors that are necessary in forming a blood clot.
Deficiencies in factors VIII and IX are well known to most people, but what of the other factor deficiencies? Not everyone is as familiar with these conditions because they are diagnosed so rarely. To date, deficiencies in eight of the lesser known coagulation factors have been documented in the medical literature. Many of these disorders were only discovered or described within the last 40 years.
Rare Factor Deficiencies Are Not Sex Linked
In most cases, rare factor deficiencies are not genetically sex-linked. They occur in equal frequency among men and women. By and large the gene is passed down in an autosomal recessive fashion. This means that when the factor deficiency is inherited from only one parent, the child will be a carrier of the condition, but usually not have symptoms. It is possible for people to inherit a gene from both parents, but this happens very rarely and usually means a more severe manifestation of the disease.
Obtaining a detailed family history is an important component to diagnosing the condition. Most people with rare factor deficiencies are best seen by hematologists at hemophilia treatment centers. Making a proper diagnosis for some of these rare conditions requires a quality lab and an experienced hematologist. To find a treatment center located closest to you, click here.
Not All Factor Deficiencies Have The Same Severity
Not all factor deficiencies have the same severity. Not everyone with these disorders needs treatment. However for those who do, the treatments available for people with rare factor deficiencies are not optimal. Many people in the United States with rare factor deficiencies need to take fresh frozen plasma, prothrombin complex concentrates (PCCs) or cryoprecipitate.
Since there are such a small number of patients with these conditions, there are few clinical studies regarding the use of products to treat them. Without solid clinical data, obtaining FDA approval for products is extremely difficult. Very few pharmaceutical companies will choose to invest the research dollars needed to produce such products for so few patients.
The above information is courtesy of the National Hemophilia Foundation.