Epidemiology of neuro-genetic disorders in Northwestern Iran.

N disorders are responsible for a major proportion of mortalities, morbidities, and handicaps across the world varying by racial, ethnic, and cultural differences. These disorders are common among developed and developing countries. Genetic disorders and congenital abnormalities occur in around 2-5% of live births accounting for approximately 30% of pediatric hospital admissions in many places in the region.1,2 The objective of this study was to estimate some epidemiological features of the neuro-genetic disorders in the northwest of Iran. In this cross-sectional study, 1613 cases (855 males and 758 females, age range: 6 months-67 years) with confirmed neuro-genetic disorders or carriers of the traits, diagnosed by molecular methods were identified in the Departments of Molecular Genetics and Epidemiology of Tabriz University of Medical Sciences, Tabriz, Iran, between January 2005 and December 2009. The data also included place of birth, year of diagnosis, and demographic information for the subjects. The area population was estimated according to the official reports for 2005-2009 from the regional Statistics Bureau. Data were considered confidential and the Ethical Committee of the Tabriz University of Medical Sciences approved the study protocol. The prevalence rate was calculated by dividing the numerator (number of cases in each disorder) by the relevant denominator (total population in the study area) for the same period of time at the same place. For statistical analysis, we calculated 95% confidence intervals (CI) for each prevalence rate. The study subjects included patients (n=889), carriers (n=614), suspected (n=109), and unknown cases (n=1). The 5-year frequency and prevalence of neurogenetic disorders by the type of disease are presented in Table 1. The most prevalent (for 5 years) disorders were identified as inherited deafness, spinal-muscular atrophy, Duchenne muscular dystrophy, and Down syndrome. Charcot-Marie-Tooth syndrome, Turner syndrome, spinocerebellar ataxia, microcephaly, ataxia telangiectasia, Anderson-Fabry syndrome, gyrate atrophy, Maple syrup urine syndrome, Sanfilippo syndrome, and inherited myopathy accounted proportionally for less than one (per 100000 populations) in the region. In this study, we investigated the frequency and prevalence of neuro-genetic disorders in the northwest of Iran. The most prevalent disorders were identified as inherited deafness, spinal-muscular atrophy, Duchenne muscular dystrophy, and Down syndrome. Similar studies from different parts of the world have reported various findings: the reports of Al-Gazali et al1 from an Arab population suggest that hemoglobinopathies including G6PD and autosomal recessive syndromes are the most prevalent disorders in the region. Some other studies in the same region have also reported similar results.2 Gonzalez-Ferrer et al3 studied 12,000 families in Venezuela. They identified Huntington’s disease, sickle cell anemia, neural tube defects, and Down syndrome as the most frequent genetic diseases in the country. The reports of Verma et al4 from India also show that thalassemia, Duchenne muscular dystrophy, Fragile X syndrome, spinal-muscular atrophy, thrombophilia, and spinocerebellar ataxias are the most prevalent genetic disorders in different regions of India. In the United Kingdom, fatty acid metabolic Brief Communication