Etiology Analysis Of Neurodevelopmental Disabilities (NDDs): Clinical Experience In A Single Center

ABSTRACT Objective This study aims to investigate the etiology distribution feature of neurodevelopmental disabilities (NDDs), so as to provide evidences for their clinical management. Subjects and Methods 285 patients referred to our department during the period from April 2002 to March 2010 were recruited as research subjects. By means of a pilot cross-sectional study, we collected and analyzed their clinical manifestations, laboratory and imaging results and metabolome findings, and summarized the etiology distribution feature of this NDDs cohort. Results The median age of the subjects was 1 year and 7 months, with minimum 1 week and maximum 16 years. The median disease course was 12 months, with minimum 4 days and maximum 9 years. Concerning NDDs classification, the proportion of non-syndromic type in the total cases was 15.8% and syndromic 84.2%, respectively. Other than NDDs presentations,21 kinds of clinical manifestations and investigation findings were revealed in patients with syndromic NDDs. NDDs patients with unknown etiologies accounted for 48.4% in the total cases, while identified etiology for 51.6%, respectively. Genetic diseases,64.7% of which were inborn errors of metabolism (IEMs), took the first place in the identified etiologies, accounting for 35.8% of the total cases. Organic acidemia was the commonest IEM type in this study, and the brain white and/or gray matter was involved in almost all such cases. Moreover, other genetic diseases including congenital malformations and chromosomal aberrations were also important causes for NDDs, taking a percentage of 35.3% in the total cases of genetic diseases. Other non-genetic causes such as psychobehavioral disorders and secondary brain injuries only accounted for 15.8% in the total NDDs cases. Conclusions 1) NDDs in this study demonstrated an etiology profile with marked heterogenicity, and most of the cases were classified into syndromic type, presenting with complex and diverse clinical manifestations and investigation abnormalities.2) Genetic diseases, including IEMs, congenital malformations and chromosomal abberations, were on top of the list of the identified NDDs etiologies.3) The etiologies in a substantial percentage of NDDs patients still remained unclear in this study, needing further intensive exploration in the future.