染色体病（Chromosome disease）.docVIP

染色体病（Chromosome disease） The fourteenth chapter is chromosome disease A disease caused by abnormal chromosome numbers or structural abnormalities is called chromosomal disorder Chromosome diseases can be divided into three kinds according to chromosome type and phenotype: autosomal disease, sex chromosome disease and chromosome abnormality carrier. The clinical and genetic features of chromosome diseases are as follows: The patients have chromosome disease congenital multiple malformations (including special face), growth, intelligence or retardation, special dermatoglyphics; Most of the patients with sporadic chromosome diseases are sporadic, that is, the parental chromosomes are normal, the distorted chromosomes come from the parent germ cells or the early cleavage of the fertilized eggs, and the new chromosomal aberrations are often absent from the family history The number of chromosomal structural aberration of patients by normal phenotype and genetic parents, one of the parents of chromosome rearrangement in carriers of balance, the chromosome of genetic aberrations to the offspring, offspring caused by chromosomal imbalances and disease, patients with this type of Chang Banyou family history. Autosomal disease (autosomal, disease) is a disease caused by abnormal autosomal numbers or structural abnormalities. Autosomal disease accounts for approximately 2/3 of chromosome diseases. Patients generally have more severe or obvious congenital multiple malformations, mental and growth retardation, often accompanied by a special pattern, the so-called triad. Down syndrome The incidence of Down syndrome The incidence of DS in neonates is about 1/1000 to 2/1000 Clinical manifestation： Generally, birth height and weight are low and muscle tension is low; Growth retardation, mental retardation; Special features: small and round head, pillow flat, flat nasal root, blepharophimosis and outward tilt, hypertelorism, epicanthus, large tongue often extended, often drooling, sm