VACTERL association

Overview
VATER syndrome or VACTERL association is a nonrandom association of birth defects. The reason it is called an association, rather than a syndrome is that all of the birth defects are linked, however it is still unknown which genes, or sets of genes cause these birth defects to occur.

Each child with this condition can be truly unique in its own way, with defects being different from any other child. At present this condition is treated after birth with issues being approached one at a time.

VACTERL association can be linked to other similar conditions such as, Klippel Feil and Goldenhar Syndrome including crossovers of conditions.

No specific genetic or chromosome problem has been identified with VACTERL association. VACTERL can be seen with some chromosomal defects such as Trisomy 18 and is more frequently seen in babies of diabetic mothers. VACTERL association, however, is most likely caused by multiple factors.

Features

 * V - Vertebral anomalies
 * A - Anal atresia
 * C - Cardiovascular anomalies
 * T - Tracheoesophageal fistula
 * E - Esophageal atresia
 * R - Renal (Kidney) and/or radial anomalies
 * L - Preaxial limb anomalies (in front of or above the central axis of the limb).

Vertebral defects
Vertebral anomalies, or defects of the spinal column, usually consist of small (hypoplastic) vertebrae or hemivertebra where only one half of the bone is formed. About 70 percent of patients with VACTERL association will have vertebral anomalies. In early life these rarely cause any difficulties, although the presence of these defects on a chest x-ray may alert the physician to other defects associated with VACTERL. Later in life these spinal column abnormalities may put the child at risk for developing scoliosis, or curvature of the spine.

Anal defects
Anal atresia or imperforate anus is seen in about 55 percent of patients with VACTERL association. These anomalies are usually noted at birth and often require surgery in the first days of life. Sometimes babies will require several surgeries to fully reconstruct the intestine and anal canal.

Esophageal defects
Esophageal atresia with tracheo-esophageal fistula (TE fistula) is seen in about 70 percent of patients with VACTERL association, although it can frequently occur as an isolated defect. Fifteen percent to 33 percent of patients with TE fistulas will also have congenital heart disease. However these babies usually have uncomplicated heart defects, like a ventricular septal defect, which may not require any surgery.

Renal / Kidney defects
Renal or kidney defects are seen in approximately 50 percent of patients with VACTERL association. In addition, up to 35 percent of patients with VACTERL association have a single umbilical artery (there are usually two) which can often be associated with kidney or urologic problems. These defects can be severe with incomplete formation of one or both kidneys or urologic abnormalities such as obstruction of outflow of urine from the kidneys or severe reflux (backflow) of urine into the kidneys from the bladder. These problems can cause kidney failure early in life and may require kidney transplant. Many of these problems can be corrected surgically before any damage can occur.

Limb defects
Limb defects occur in up to 70 percent of babies with VACTERL association and include absent or displaced thumbs, extra digits (polydactyly), fusion of digits (syndactyly) and forearm defects. Babies with limb defects on both sides tend to have kidney or urologic defects on both sides, while babies with limb defects on only one side of the body tend to have kidney problems on that same side.

Growth
Many babies with VACTERL are born small and have difficulty with gaining weight. Babies with VACTERL association, however, do tend to have normal development and normal intelligence.

The diagnosis is made if at least three of the seven defects are present in an infant.

Epidemiology
The VATER association has an estimated incidence of 1.6 cases per 10,000 live births. It is seen more frequently in infants born to diabetic mothers. It is rarely seen more than once in one family.

Pathology
Patients with abnormal cardiac and kidney function may be more at risk for hemolytic uremic syndrome.