Hereditary angioedema in Belarus: epidemiology, genetics, access to
diagnosis and therapy
Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a
rare disease. Few states in developing countries have an adequate
management of HAE, but none of them belongs to the former USSR area.
This study analyses data from C1-INH-HAE patients from Belarus. Data
about clinical characteristics, genetics, access to diagnosis and
treatment were collected from 2010 by the Belarusian Research Center for
Pediatric Oncology, Hematology and Immunology in Minsk. A questionnaire
about attacks, prophylactic (LTP) and on-demand therapy (ODT) was
administered to patients. We identified 64 C1-INH-HAE patients belonging
to 26 families, 27 (42.2%) of which were diagnosed in the last 3 years.
The estimated minimal prevalence was 1:148000. Median age at diagnosis
was 29 years, with diagnostic delay of 19 years. Thirty-eight patients
answered a questionnaire about therapy. Seventeen (44.7%) underwent
ODT: 6 (15.8%) with appropriate treatments, and 11 (28.9%) with
inappropriate treatments. Nine (23.6%) used LTP with attenuated
androgens and twelve (31.5%) recovered spontaneously. Thirty-two
patients answered a questionnaire about attacks and triggers: 368
angioedema attacks were reported, with an average of 10 attacks per
year. We found 24 different SERPING1 variants: 9 missenses, 6 in splice
sites, 6 small deletions, 2 nonsense, 1 large deletion; 7 have not been
previously described. De novo variants were found in 11 patients.
C1-INH-HAE diagnosis and management in Belarus is improved as seen from
the high number of new diagnosis in the last 3 years. Next steps will be
to reduce the diagnostic delay and to promote the LTP and OTD.