Ichthyosis is not 100% hereditary. Clinically, ichthyosis can be divided into normal type, sex-linked type, lamellar ichthyosis and other types. 1. Ordinary type ichthyosis: this type of ichthyosis is autosomal dominant. When one or both parents are heterozygous, the hereditary probability is 100%; if one parent is heterozygous, the probability of hereditary to children is 50%; when both parents are heterozygous, the probability of children’s disease is 75%. 2. Sex-linked ichthyosis: This type of ichthyosis is associated with X recessive inheritance, the inheritance rate is related to gender. If only the mother is a patient, the probability of her daughter having the disease is 0%, and the probability of her son having the disease is 100%; when the mother is a carrier and the father is a patient, the probability of the children having the disease is 50%; if only the father has the disease, the probability of his son having the disease is 0%, and the probability of his daughter having the disease-causing gene is 50%. 3. Plate-like ichthyosis: this type of ichthyosis is autosomal recessive. When both parents are patients, the probability of their children having the disease is 100%; if only one parent is a patient, the probability of heredity is 0%; if one parent is a carrier and the other is a patient, the probability of heredity to the children is 50%. In summary, ichthyosis is not 100% hereditary, for the specific mode of inheritance and hereditary probability, you can consult a professional doctor to determine.