ABSTRACT
OBJECTIVE: Specific learning disorder (SLD) is a neurodevelopmental disorder in which underlying pathogenesis and etiological factors are not fully understood. Neuroinflammatory response (measured with serum levels of galectin-1 and galectin-3), which is associated with learning and memory, may play an important role in the etiopathogenesis of SLD. Aim of the present study is to examine whether serum galectin-1 and galectin-3 levels are related to SLD. METHODS: The current study consisted of 42 treatment-naive children with SLD and 42 control subjects. All of the subjects were assessed using semi-structured psychiatric examination to diagnose SLD and exclude attention-deficit hyperactivity disorder. Serum galectin-1 and galectin-3 levels were measured via venous blood samples. RESULTS: The SLD and control group did not differ significantly in terms of age, sex, and body mass index (BMI). The SLD group had significantly higher serum levels of galectin-1 (8.78±2.97 vs. 7.40±2.03, p=0.019) and galectin-3 (1.86±0.93 vs. 1.32±0.69, p=0.003) than the control group when controlled for age, sex, and BMI. CONCLUSION: Higher serum levels of galectin-1 and galectin-3 in children with SLD may indicate the role of neuroinflammatory response in the pathogenesis of SLD. Other mechanisms involving galectin-1 and galectin-3 related to learning may play a part in the etiology of SLD.
ABSTRACT
Introduction: Specific learning disorder (SLD) is a neurodevelopmental disorder that involves complex interactions of genetic, neurobiological and environmental factors, but the definite mechanisms remain mostly unknown. The possible role of neurotrophins has been implicated in the pathophysiology of various neurodevelopmental disorders. This study aimed to investigate whether serum levels of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3) in children with SLD deviate from those of neurotypical brains. Methods: Forty-four patients with SLD and 44 healthy controls aged 7--12 years were included. SLD diagnosis and severity was determined using DSM-5-based interviews and SLD clinical observation battery. Serum neurotrophins were measured using enzyme-linked immunosorbent assay. Results: BDNF (p=0.032), NGF (p=0.029), and NT-3 (p=0.025) serum levels were significantly higher in the SLD group compared to the control group; however, serum levels of GDNF did not show any significant difference between groups. On the other hand, GDNF serum levels were significantly different between mild and severe SLD groups (p=0.007) and were lower in severe SLD subjects than in mild cases. There was also a significant correlation between patients' reading speeds and serum levels of GDNF (p=0.025), and GDNF serum levels were lower in patients with slower reading speeds. Conclusion: These findings suggest that neurotrophins might play a role in the pathophysiology of SLD. Increased serum levels of BDNF, NGF, and NT-3 might reflect compensatory attempts at neuroprotection against neurodevelopmental impairment.
