Intellectual Disability Onset Research Articles

Estimation of Risk Factors for Intellectual Disability in North Karnataka Region: A Retrospective Analysis

Introduction: Intellectual disability (ID) is a neurodevelopmental disorder characterized by three main clinical conditions, i.e., cognitive deficiencies, impairments of adaptive function, and onset during the developmental period. The causes of ID include genetic abnormalities, as well as prenatal, perinatal, and postnatal environmental factors such as exposure to toxic agents, nutritional deficiencies, childhood brain infections, and maternal infections such as rubella and cytomegalovirus may lead to ID. The present study attempted to perform a detailed analysis of case histories of children with ID among North Karnataka region to examine the frequency of occurrence of risk factors which can cause onset of ID. Methods: Retrospective analysis of records of 1400 individuals who visited our Institute, for speech and language evaluation was analyzed. Among 1400 cases, there were 300 cases were selected for the study. Results: The risk factors identified in this study primely constitute of perinatal and postnatal factors and lower socioeconomic status. Conclusion: It may be implied from the results of the study that appropriate peri and postnatal health care interventions can help to reduce risks leading to ID. Utilizing this knowledge will help with both primary and secondary level prevention by raising public awareness of the probable causes of ID. It is also possible to identify these risk factors, detect ID early, and then intervene at the earliest. Furthermore, extensive researches focusing on a thorough evaluation of risk factors with respect to severity of ID need to be carried out. This will help in understanding the causative factors better, and hence, enhance the development of preventive strategies and planning of a better rehabilitation program.

THEORETICAL ASPECTS OF INTELLECTUAL DISABILITY - DEFINITION, CLASSIFICATION

The onset of intellectual disability is marked by impairment of all parts that contribute to an individual's intelligence, such as the functions of socialization, knowledge, speech, and motor function. Intellectual disability is also defined, involving significant limitations in both intellectual functioning and adaptive behavior, which cover many daily social, motor, and practical skills. The most commonly accepted definition of intellectual disability is that provided by AAIDD: “Intellectual disability is a disability characterized by significant reductions in both mental functioning and adaptive behavior, covering many daily social and practical skills. This disability originates before the age of 18.”

Risk of intellectual disability and maternal history of spontaneous abortion: a nationwide cohort study.

To investigate the association between a maternal history of spontaneous abortion and intellectual disability in children. This cohort study included 1778786 children (913 340 males, 865 085 females, 361 missing data; mean age 15y 2mo, SD 8y 11mo, range birth to 40y) born in Denmark between 1977 and 2016. Cox proportional hazard regression was used to estimate the hazard ratios (HRs) of intellectual disability. The overall HR of intellectual disability for children with a maternal history of spontaneous abortion was 1.17 (95% confidence interval [CI] 1.12-1.22) and the risk for multiple spontaneous abortions (HR=1.30, 95% CI 1.20-1.40) was higher than for a single spontaneous abortion (HR=1.13, 95% CI 1.07-1.18). When only cases of inpatient intellectual disability were included, the estimates increased slightly: the overall HR was 1.22 (95% CI 1.12-1.32), the HR for multiple spontaneous abortions was 1.37 (95% CI 1.20-1.58), and the HR for a single spontaneous abortion was 1.17 (95% CI 1.07-1.28). The risks were similar regardless of whether spontaneous abortion occurred before or after the index delivery. Estimates were nearly unchanged after adjusting for preterm birth, low birthweight, or Apgar score. Children born to mothers with spontaneous abortion, especially multiple spontaneous abortions, may be at a higher risk of intellectual disability in later life, regardless of whether spontaneous abortion occurred before or after the index delivery. The findings have clinical implications for targeted early intervention of children with intellectual disability. What this paper adds A maternal history of spontaneous abortion was associated with a risk of intellectual disability in offspring. The risk was higher in children whose mothers previously had multiple spontaneous abortions. Similar risks were observed regardless of whether spontaneous abortion occurred before or after childbirth.

Involvement of IL-6 and IL-1 receptor antagonist on intellectual disability

Imbalances in the regulation of pro-inflammatory cytokines have been increasingly correlated with several neurodevelopmental disorders and their role in neuronal development is being investigated. To assess the possible influence of cytokines on the onset of intellectual disability (ID), we studied the polymorphisms of thirteen proinflammatory cytokine genes in 81 patients and 61 healthy controls. We demonstrated a significant association of interleukin-6 (IL-6) single-nucleotide polymorphism (SNP) (−174 G/C and nt565 G/A), and interleukin-1 receptor antagonist (IL-1RA) (Mspa-I 11100) SNP with ID. Moreover, the IL-6 SNPs is an unfavorable genetic predisposition for females. The evaluation of circulating levels of IL-6 and IL-1RA showed that the serum concentrations of IL-6 were significantly higher in ID patients than in controls. These data suggest that functional cytokine gene polymorphisms may influence the development of ID.