Antley-Bixler syndrome

Antley–Bixler syndrome (ABS) is a rare genetically determined congenital disorder. It primarily affects the skull and limbs; sometimes the urinary and genital systems may also be impaired.

Causes:

The disease is caused by a genetic mutation. It may involve a mutation in one of the genes important for the proper function and development of connective tissue, or a defect of the gene essential for the function of the cytochrome P450 oxidoreductase enzyme. Disruption of this enzyme leads to disorders in the synthesis of steroid hormones.

Symptoms:

The affected individual has a deformed shape of the skull, which is shortened; the face is underdeveloped, and the nose is flattened. Premature fusion of the cranial sutures also occurs, which prevents the skull and brain from growing, compresses the brain, and may lead to dangerous increases in intracranial pressure.

Deformities also affect the bones of the limbs, for example the femur or the bones of the forearm, which may be bowed. The disease also affects the joints of the limbs, which develop poorly and may be practically immobile. In cases where the gene for cytochrome P450 oxidoreductase is disrupted, steroid hormone synthesis is impaired, with the most prominent being a deficiency of sex hormones. The consequence is impaired development of the individual’s genital organs and sexual characteristics — undescended testes and a small penis in boys, a blind‑ending uterus or fused labia minora in girls. However, these genital anomalies do not occur in all cases of Antley–Bixler syndrome. The prognosis of the disease is not very good; most affected individuals die in childhood.

Diagnosis:

As with many other genetic disorders, suspicion can be obtained from the symptoms, but definitive confirmation is provided only by genetic testing. Prevention of genetically determined disease is currently not possible.

Treatment:

There is no treatment for the syndrome as such. Deformities may be addressed through surgical and orthopedic procedures.

• deformovaný tvar lebky
• nos spološtený, tvár málo vyvinutá
• predčasný zrast lebečných švov
• narušený vývoj pohlavných orgánov (nezostúpené semenníky, malý penis, slepo končacia maternica, zrastené pysky)