Results of the clinical and genetic diagnosis of rare diseases in the Eastern region of Hungary (2007-2013)

Introduction: 80% of rare diseases have a genetic origin, and 50% manifest themselves as congenital anomalies. Their adequate health care includes early recognition of genetic anomalies and prevention of recurrence. Aim: The aims of the authors were to provide correct diagnoses to patients with multiple congenital anomalies with or without mental retardation attending to the outpatient clinic of the Clinical Genetics Center at the University of Debrecen in the time interval between August 1, 2007 and March 31, 2013, establish the possibility of prenatal diagnosis, assess the distribution of different genetic mechanisms in the background of rare genetic diseases, compare them with international data, and develop an algorithm for the diagnostic approach of rare genetic diseases applicable in Hungary. Method: Clinical data and genetic results of patients were evaluated, and patients were categorized into one of the ten proposed etiological groups, based on which the distribution of genetic causes was defined. Results: Clinical diagnosis was achieved in 64.3% of patients, confirmed genetic diagnosis in 37.8%, while 35.7% of patients remained undiagnosed. Several dysmorphic syndromes and metabolic disorders were first diagnosed in Hungary, two of which unique in the literature. Conclusions: In the centre of the authors the diagnostic effectiveness of chromosome aberrations exceeds the international standards, that of known microdeletions and dysmorphic syndromes meets international data, and the genetic diagnosis of mendelian disorders and submicroscopic copy number changes remain below international figures.