Children with BGS are born with premature closure of the joints or seams (sutures) of the skull. This causes an upward growth of the head giving it a pointed or cone-shaped appearance. The large bone of the forearm on the “pinky” side (ulnar) is short and curved and the short bone of the forearm on the thumb side (radius) is underdeveloped or missing. These Skeletal abnormalities may be present on both sides or just one (asymmetric). Sometimes, other bones in the hand called the carpal and metacarpal bones may also be missing or formed differently. Problems with fine motor skills may be present due to the deformities of the hands and arms. Underdevelopment or absence of the kneecap (patella) may also occur. In some people with BGS, other Skeletal abnormalities involving the spine and pelvis are seen.
Slow growth is also a feature of BGS. Delayed growth in childhood may result in height and weight significantly below average. Heart defects can sometimes be seen in people with BGS. The more common heart defects that have been described in the medical literature on BGS are ventricular septal defects, tetralogy of Fallot, and congential portal venous malformations. Each of these terms describes a different change to development of the structure of the heart. The severity of a heart defect depends on the type of structural issue and the individual case. Some heart defects may require surgical correction, whereas others may resolve naturally over time.
People with BGS have distinct facial features, including a protruding forehead, widely-spaced eyes, short nose, and small mouth. The palate, or roof of the mouth, may have a high arched appearance. The fontanelles, or the soft spots on an infant’s skull, may appear larger than would be expected. In the first few years of life, the skin may be discolored or shed easily. This is called poikiloderma.
Intellectual disability has been reported in BGS. However, most individuals have normal intelligence.
In some people with BGS, the anus may be further forward than is typical (anteriorly placed), and the opening to the anus may be missing or blocked (imperforate anus). These structural abnormalities can involve a fistula, which results in an abnormal connection between the anus and genitalia. In such cases, surgical repair may be possible.
People with BGS or carriers of the condition, may be at increased risk for certain types of cancer. These include osteosarcoma, a type of bone cancer; skin cancer; and lymphoma. The medical literature links mutations in the RECQL4 gene to increased cancer risk. Signs and symptoms for these types of cancer can include bone pain, Swelling and fractures for osteosarcoma, or lymph node enlargement, Fever and unexplained weight loss for lymphoma.