Caudal regression sequence

We are not aware of reports in the medical literature that describe blue feet (acrocyanosis) as a symptom in children with caudal regression syndrome.

A bluish discoloration of the skin is called cyanosis. When cyanosis affects the extremities (the hands and feet), it is referred to as acrocyanosis. Acrocyanosis is due to reduced oxyhemoglobin (hemoglobin that carries oxygen to tissues in the body). In other words, there is a decreased amount of oxygen delivered to the affected body part(s). Reasons for this condition may include some pulmonary and cardiac (heart) conditions, causing oxygenation problems; and/or local tissue oxygenation problems. Acrocyanosis is not infrequent in people with major neurological deficits, especially those with muscle function loss or paralysis.^[1]

While acrocyanosis is usually a benign condition without any serious complication, some types can be serious and require treatment.^[1] Furthermore, an accurate diagnosis is important, as symptoms of the condition may overlap with those of other conditions. Therefore, it is recommended that discoloration of the skin (especially when an underlying condition is present) be discussed with a healthcare provider.

The signs and symptoms of caudal regression syndrome vary depending on the severity of the condition. Affected areas of the body may include the lower back, limbs, the genitourinary tract, and the gastrointestinal tract.

The bones of the lower spine are often abnormally shaped or missing, and the corresponding sections of the spinal cord are also abnormal or missing. Affected people can have scoliosis or other abnormalities of the spine. Spinal abnormalities may affect the chest, which can lead to breathing problems.

Some affected people have small hip bones with a limited range of motion. The buttocks may be flat and dimpled. The leg bones are often underdeveloped. In some people, the legs are bent with the knees pointing outward and the feet tucked underneath the hips. Other features affecting the limbs may include clubfeet, calcaneovalgus, and/or decreased sensation in the lower limbs.

Abnormalities of the genitourinary tract are extremely varied. There may be malformations of the kidneys or absence of a kidney, or kidneys that are fused together (horseshoe kidney). Kidney abnormalities can lead to urinary tract infections and progressive kidney failure. There may also be abnormalities of the bladder, or damage to the nerves that control bladder function. Affected males may have hypospadia (the urethra opening on the underside of the penis) or undescended testes. Affected females may have an abnormal connection between the rectum and vagina. In severe cases, an affected person may have no genitalia (genital agenesis).

Gastrointestinal features may include malrotation of the large intestine, an obstruction of the anal opening, and/or inguinal hernias. Constipation and loss of bladder or bowel control are common.^[2]