Specificity and etiologic mechanism of developmental disorders-like symptoms for extremely low birth weight children.

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K04061
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Educational psychology
• Research Institution: Osaka University
• Principal Investigator: KANAZAWA Tadahiro 大阪大学, 人間科学研究科, 教授 (30214430)
• Research Collaborator: ISAKI Motohiro
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 超低出生体重児 / 学齢期 / 発達障害様症状 / 発症メカニズム / 周産期合併症 / 共有環境

Outline of Final Research Achievements

For 220 ELBW children at school age, 9.5% of the subjects were classified as intellectual disability (ID); 9.1% as having borderline intelligence; 23.2% as LD; 15.9% as ASD; 20.5% as ADHD. IVH increased the risk for lower IQs, higher ASSQ scores, and lower nonverbal PRS scores. Grade 3 or 4 IVH was also associated with inattention. Children suffering from CLD showed the lower IQ and PIQ. ROP was associated with lower PIQ. Among these perinatal complications, severe IVH might be the most important risk factor of ASD. The relative contribution of genetic and environmental influences to developmental disorders were assessed for 45 same gender twin pairs: 24 were MZ and 21 were DZ pairs. While parameters of genetic influences were higher on Hyperactivity-Impulsivity, Ones of shared environmental influences were higher on ASSQ and Inattention.These findings indicate that the shared environment has relatively larger influences on incidence of ASD and Inattention for ELBW children.

Free Research Field

発達心理学

Academic Significance and Societal Importance of the Research Achievements

学齢期の極・超低出生体重児にASD、LD、ADHDなどの発達障害様の症状が高率で認められた。発達障害様症状の発症には脳室内出血、慢性肺疾患などの周産期合併症が影響を与えていることが示された。さらに、一卵性双胎と二卵性双胎の比較により遺伝率よりは共有環境の寄与率が高いことが示され、発症メカニズムに周産期の環境要因が関係している可能性が確認された。ASDは遺伝的な要因が優勢とされるが、通常とは異なり周産期因子が後生的に作用している可能性が強まった。周産期合併症に関しては周産期医学の進歩により今後その医学的予防や医学的治療が可能になれば極・超低出生体重児の発達障害様症状の軽減につながるかもしれない。