Let's build the pedigree of litigant A who is a 30-year-old male with a skin deformity. From a young age, shortly after giving birth, litigant A's skin became dark and covered with coarse scales with cylindrical papillae about 2.5 cm long, covering all over the body except on the hands, heels, head and face. Applicant A's wife is a healthy person with no genetic diseases. They have a 5-year-old son who also has a skin deformity like his father and his pregnant wife.
Applicant A's family has 9 brothers and sisters, and litigant A is the fourth child in the family. The three older sisters and the four close sisters of litigant A all have normal phenotypes. The youngest brother of litigant A is also deformed in the skin like litigant A.
Complainant A's mother has a normal phenotype, while litigant A's father and his five younger brothers (applicant A's uncles) also have skin malformations like applicant A's. These uncles are not married. and have no children.
Applicant A's grandfather also has a skin deformity, while his grandmother has a normal phenotype.
Applicant A's maternal grandparents are healthy people with no genetic diseases.
* Set up family according to the above situation: