syndrome in males that is characterized by small testes and long legs and enlarged breasts and reduced sperm production and mental retardation; a genetic defect in which an extra X chromosome (XXY) is present in the male

男性において、小さな精巣、長い脚、肥大した乳房、精子生産の減少、知的障害を特徴とする症候群。男性に余分なX染色体（XXY）が存在する遺伝的欠陥。