Clinical characteristics include emaciation, irregular intake of food and, if extreme, dry, slack skin, vexation, agitation, listlessness and retarded mental and motor development.

• 其临床特徵为形体消瘦，饮食不调，甚则皮肤乾燥松弛，精神烦躁或萎靡不振，动作、智能发良迟缓。