The specific examinations are as follows: 1. First of all, we must conduct an interview with this kind of child: we must bring the child to the doctor and let the doctor examine him. Observe whether this child has a special face, whether there are any somatic deformities, and also check whether there are some color changes on the body, such as spots or other problems, and also look at the child’s eye contact with others, voice understanding, listening to instructions, and also check whether the child’s muscle tone is normal, and whether there are any abnormal postures, or abnormal movement patterns. Next, we assess whether the child’s development is up to standard in various abilities, such as gross motor, fine motor, language, and social skills. Then the physical development level is measured, such as height, weight, hip circumference is in the normal range; 2. Medical history collection: start from the mother’s pregnancy, ask the mother if she was sick during pregnancy, nutrition, pregnancy vomiting, emotions, etc., followed by the baby’s birth, if it is a full-term child, if the birth weight is normal, if there is asphyxia. Then ask about the child’s growth and development history, growth, feeding, living environment, etc. We also need to know the family history, whether there is any genetic metabolic disease or developmental delay in the family; 3. Auxiliary examination: to understand the metabolic situation of the child, check the biochemical whole, blood ammonia, growth level, such as growth hormone, thyroid function, blood lead examination, because the high lead may affect the development of the child. Then we should look at the level of brain development, or whether the brain waves are normal, do EEG, cranial MRI, and eventually the cause of the disease should be genetic examination, through these aspects of a comprehensive consideration.