The heel blood is mainly checked for phenylketonuria (PKU for short) and hypothyroidism (CH for short), two diseases that can cause severe mental retardation in babies if left untreated, but if detected early, diagnosed and treated early in the neonatal period, serious damage to the baby can be avoided. Phenylketonuria Phenylketonuria (PKU) is an autosomal recessive genetic disorder. It is named after the metabolism disorder of phenylalanine in babies and the discharge of large amounts of metabolites such as phenylketonate in the urine. Phenylalanine is one of the essential amino acids, and after being taken into the body through food, part of it is used by the body for protein synthesis and the rest is converted into other substances. Phenylalanine is not properly metabolized in babies and accumulates in the body, causing damage to the central nervous system and a series of pathological changes. Signs of the disease Babies with the disease will gradually develop abnormalities in the nervous system, such as black hair turning yellow, white skin and light iris of the eyes, increased muscle tone, abnormal gait, subtle hand tremors, and repetitive limb movements. What is especially noteworthy to parents is the very unpleasant smell of rat urine in the baby’s urine. In addition, babies are prone to eczema, vomiting, and diarrhea. In treatment, a low-phenylalanine diet is used to ensure the supply of various nutrients needed for normal growth and development of the baby, while avoiding excessive intake of phenylalanine. Once diagnosed, treatment should be given immediately. The earlier the treatment, the better the prognosis. TIPS 1. Make sure to strictly control your baby’s diet according to your doctor’s requirements. Phenylalanine should neither be consumed too much nor too little, as insufficient supply of phenylalanine can also lead to growth retardation. 2.Regularly adjust the recipes, usually once a month for babies under 1 year old, once every 2 months for those over 1 year old, and once every 3 to 4 months for school-age children. 3, breastfeeding under the guidance of doctors, do not stop breastfeeding. 4.Regularly review your baby’s blood phenylalanine concentration, and check your baby’s physical and intellectual development every 6 months to 1 year. 5, treatment at least until puberty maturity, preferably lifelong treatment. 6, female PKU baby to childbearing age, need to start strict dietary control six months before pregnancy, monitoring blood phenylalanine concentration until delivery, so as not to affect the fetal neurological development. 7, the prevention of phenylketonuria is to avoid consanguineous marriage; couples with PKU babies should undergo genetic testing for both spouses before they become pregnant again, and genetic testing for the fetus after pregnancy. Hypothyroidism Hypothyroidism (CH) is caused by congenital factors that reduce the secretion of thyroid hormones, resulting in growth disorders and mental retardation in babies. Signs of the disease Newborn babies: mainly manifest as immobility, non-crying, poor response, sleepiness, low muscle tone, in addition to often having difficulties in breastfeeding, bloating, constipation, prolonged physiological jaundice, low body temperature, etc. After 3 months of age, the following manifestations gradually appear Special facial features: bloated face, wide eye spacing, flattened nasal bone, large, broad tongue often sticking out of the mouth, and dry hair. Special body posture: short stature, upper body larger than lower body, large head and short neck. Special standing and walking posture: lumbar vertebrae protruding, knees slightly flexed, walking swaying. Special development: the baby is late in raising the head, sitting, walking and teething, late closure of fontanel, and backward in intelligence. The treatment of this disease is very simple, the baby can be given thyroxine supplement. TIPS 1. Early treatment can prevent the child from becoming disabled. 2, must adhere to the long-term treatment, can not increase or decrease the amount of medication or interrupt the treatment. 3, there is no effective preventive measures for this disease. Therefore, early detection, early treatment and long-term adherence are very important. Congenital adrenocortical hyperplasia is also known as adrenogenital syndrome or adrenal metaplasia. It is mainly due to defects in the enzymes necessary for the biosynthesis of adrenocortical hormones, resulting in abnormal synthesis of corticosteroids. Therefore, clinical hypoadrenocorticism of varying degrees is seen, accompanied by masculinization in girls and precocious puberty in boys, in addition to various syndromes such as hyponatremia or hypertension. Treatment should be early application of hydrocortisone or prednisone; lifelong medication or surgery should be adhered to. Glucose-6-phosphate dehydrogenase deficiency is an inherited metabolic defect that is inherited as an X-partnered incomplete dominant trait, with more males than females. Due to the many variants of G6PD deficiency, the clinical manifestations vary greatly. Light cases can be asymptomatic, while heavy cases can manifest as congenital non-spherocytic hemolytic anemia, usually manifested as acute hemolysis induced by taking certain drugs, fava beans or after infection, and heavy cases can be life-threatening. Prevention of this disease is important. Patients diagnosed with the disease should abstain from eating fava beans and taking certain drugs thereafter.