A brief review on clinical classification and pathophysiologic considerations of

Because of efficient progress in controlling common and lethal environmental, infectious and nutritional disorders, gradually referral for genetic and metabolic disorders are being more common. Currently about 20 to 30% of referral and academic hospital beds are occupied by these patients. Also, about 20% of mortality of patients in the early pediatric age group belongs to these disorders. More than 100 years ago for the first time, Sir Archibald Garrod introduced some metabolic disorders. More than 500 different phenotypes of metabolic disorders identified and categorized in the literature. There are a huge number of very different metabolic pathways inside the cells. In a metabolic pathway, a biochemical molecule in a step by step reaction synthesized or degraded and changed to the new one. If the responsible enzyme was deficient in a specific reaction, a block in that pathway will occur. The end result would be accumulation of the enzyme’s substrate or deficiency of its product. Both of them can cause apoptosis or cell death and a specific disabling or serious phenotype. In this article I will try to explain some of the clinical and pathophysiologic characteristics and classification of these rare disorders briefly. Also I will explain available modern technologies that are used for evaluation, diagnosis, treatment, prevention, and screening. I believe that by considering the mentioned issues, we will be able to approach better and more logically confronting these patients. For some of these disorders specific treatment is available. For those that there is no therapy, reaching an accurate diagnosis will help us to offer necessary information in genetic counseling sessions, and prevent the recurrence of the tragedic problem in the next pregnancies.