This is an Investigator initiated retrospective and prospective single cohort study. The study will utilize an international registry and develop a specimen biobank to provide an improved understanding of the natural history of hyposplasminogenemia, to elucidate the heterogeneity of phenotypic expression, identify markers to predict disease course, and inform improved therapeutic modalities

The aims of this study are to:

1. Define PLGD natural history in a large cohort of individuals with hypoplasminogenemia and their first-degree family members.
2. Identify factors that correlate with disease expression and severity.
3. Create a specimen biobank for further studies, available to other researchers.

The project will be international in scope with two collaborating centers that have created and will collect the subject data and samples. In North/Central/South America, the Indiana Hemophilia & Thrombosis Center (IHTC) will serve as the primary site while University of Milan will serve as the center for all other sites. The database is housed at the University of Milan, Italy.

Study population will include males and females affected with hyposplasminogenemia of any age. Both one-year retrospective and three-year prospective data will be collected on an international cohort of 100 affected individuals and their first degree family members (parents, siblings; total estimated study population ~500).

Study sample analysis, except for urine analyses, will be centralized and performed in Italy; the plasminogen antibody analysis will be batched for analysis, and the urine analyses will be performed locally. A sample biorepository will be created and ultimately housed in Italy. The study will provide testing for plasminogen activity and antigen, plasminogen genetic analysis, polymorphisms in genes that impact plasminogen expression and fibrinolysis, and global hemostatic assays. In addition, stored samples will be used for further testing and analyses to potentially include whole genome sequencing to further identify plasminogen genetic mutations as needed and to investigate other genetic modifiers of disease expression. An exploratory aim includes investigating the potential relationship with streptococcal strains and altered plasminogen products.

The study period will be 3 years for each enrolled subject. In-person visits will be conducted and samples for analysis will be collected at baseline and at end of study. Interval follow-up will be performed every 6 months by telephone. data will be collected at unscheduled visits that are performed for clinical need at the treating physician's discretion.

Inclusion Criteria:

1. Signed informed consent and assent as applicable (Appendix 1)
2. A. Males or females with type 1 PD diagnosed locally with plasminogen activity levels <50% OR B. First degree family members of a person diagnosed with type 1 PD (includes parents, siblings, half-siblings)
3. All ages included
4. Available clinical history and treatment for at least 1 year prior to entry except for infants < 1 year of age
5. Willingness to provide samples for analysis including DNA, plasma etc.
6. Willingness to participate in prospective follow-up for up to 3 years

Exclusion Criteria:

1. Previous organ transplant recipient
2. Any psychiatric disorder, other mental disorder, or any other medical disorder that impairs the subject's ability to give informed consent or to comply with the requirements of the study protocol
3. Refuses to provide informed consent
4. Special patient populations, including prisoners or, are deemed medically or cognitively unsuitable for research by their treating physician
5. Inability to obtain a blood sample due to poor or limited venous access

Study population will include males and females affected with hyposplasminogenemia of any age and their first degree family members (siblings and parents).