Genetic encoding of the International Classification of Diseases and the burden of Genetic Disorders [Poster walk]

Background Genetic diseases are an important cause of infant mortality and morbidity and have a high impact on social-health system. About 50-70% of pediatric patients suffer from genetic disorders or diseases with a significant genetic component. At the time, the key role of genetics in understanding the biological basis of the disease has been well defined but its real impact remains to be defined. The aim of this study is to assess the impact of genetic disorders through the ‘‘genetic encoding’’ of the International Classification of Diseases-9th Revision (ICD9), currently used in Italy, in order to understand the implications for the healthcare system. Methods This study included the following activities: ‘‘Genetic’’ classification of the diseases according to scientific literature; ‘‘Genetic encoding’’ of disorders present in ICD9 using as resource the Online Mendelian Inheritance in Man (OMIM); Selection of ICD9 codes relevant for the study. Results The analysis of literature resulted in a ‘‘genetic’’ classification of 8 classes of diseases: Chromosomal anomalies, Monogenic disorders, Congenital Malformations, Mitochondrial diseases, Genomics diseases, Somatic cell genetic diseases, Multifactorial Disorders, Probably genetic disorders. According to the ‘‘genetic encoding’’ of the ICD9 about 29% of ICD-codes is ‘‘genetic’’. The most represented classes are: Multifactorial Disorders (37,9%), Somatic cell genetic diseases (30,6%), Congenital Malformations (14%) and Monogenic disorders (10,6%). Conclusions Genetic diseases are quite common and costs for society and for the health system are very high. The ICD9 has some limitations: for example it does not include all genetic diseases currently known with consequent possible coding errors by clinicians and incorrect correlation with Diagnosis Related Groups. These results are of major interest for public health not only for assessing the burden of genetic disorders but also for priority setting in resources allocation.