Diastrophic dysplasia

Diastrophic dysplasia (DD, DTD) is a genetic disease caused by a mutation in the DTDST gene, inherited in an autosomal recessive manner (you need to inherit this gene from both parents to get DTD). It is also known as diastrophic dwarfism. Bone dysplasia is a rare disorder - it occurs at a frequency of about 1 in 110,000 births and affects both males and females equally.

Diastrophic dysplasia is a disorder involving the bones, cartilage and connective tissues of the body. Normal bone formation is disrupted, resulting in short stature and joint damage. In addition to limited growth - in adult life it is about 110-130 cm, and accelerated bone age, it is characterized by curvature of the spine and curvature of the toes and fingers (very short limbs, abnormally formed and shortened feet). A dangerous complication of the disease is respiratory failure, resulting from abnormal structure of organs containing cartilaginous tissue (larynx, trachea and bronchi), which can lead to death in the neonatal period. Inflammatory swelling of the auricular cartilages and sometimes cleft palate are often found. The intelligence level of people with connective tissue dysplasia is normal.

The incidence and severity of symptoms of diastrophic dysplasia vary. Characteristics include:

1. limb shortening,
2. small chest,
3. prominent abdomen,
4. cleft palate,
5. Cystic inflammatory swelling of the auricle cartilages, giving the ears a "cauliflower" shape,
6. joint contractures,
7. Curvature of the fingers and toes,
8. Shortening of the bones of the hand, including proximal positioning of the thumbs - the "hitchhiker's thumb."
9. Equinus feet, due to bone lesions - ranging from a mild to severe condition,
10. Progressive scoliosis (lateral curvature of the spine), curvature of the lumbar spine (forward curvature of the lower spine), kyphosis of the cervical spine,
11. Bone fusions of the metacarpophalangeal joints.

The diagnosis of the defect can be made on the basis of prenatal ultrasound results or during the first months of life, when the cystic swelling of the ears becomes apparent. The patient's medical history and family history of disease should be carefully reviewed, as well as reports of all surgeries performed to date.

Most patients with diastrophic dysplasia have accentuated cheeks and full lips. The face is full and drawn, with a high and wide forehead, and a square jaw. There may also be a characteristic hoarse cry (voice disorder), which is caused by palatal abnormalities.

A large group of people with bone dysplasia have changes in the spine - cervical kyphosis, which can even lead to quadriplegia with paralysis of the respiratory muscles; scoliosis and significant curvature of the lumbar spine. Kyphoscoliosis can cause an imbalance of the trunk, leading to difficulty in walking and further lowering an already short stature. Some patients need to get around in a wheelchair or use a walker, walker or scooter. Spinal lesions can also cause breathing difficulties.

Connective tissue dysplasia cannot be completely cured. Symptomatic treatment, including surgical treatment, is used. At Paley European Institute, we perform hip, knee and foot reconstructions in pediatric orthopedic patients with DTD. Growth can also be increased by performing limb lengthening, but this is not always advisable due to the severe joint problems in these patients.