The parents of a 6-year-old boy complain of pain and paresthesia in their child's legs, the child quickly tires when walking. Objectively, the following is observed: disproportionate development of the muscles of the upper and lower shoulder girdle, hypotonia of the leg muscles, no pulsation on the femoral arteries, significantly weakened pulsation on the abdominal aorta, systolic murmur in the inter scapular area. Blood pressure in the arms 140/100 mm Hg, blood pressure in the legs 80/40 mm Hg. X-ray detects severe erosions (usurations) on the ribs. What is the most likely diagnosis in this case?