An 8-year-old child is being monitored for growth retardation. The child was born with asphyxia and the body weight of 2800g. He studies well at school. His parents are of average height. Objectively, height - 107 cm, body weight - 23 kg, he has underdeveloped facial skeleton that resembles a doll's face. The hair is thin, the skin is dry with an icteric tint. Subcutaneous adipose tissue is well developed on the neck, chest, and abdomen. The muscles are underdeveloped. What is the most likely diagnosis in this case?