Frontometaphyseal dysplasia

Frontometaphyseal dysplasia is a disorder involving abnormalities in skeletal development and other health problems. It is a member of a group of related conditions called otopalatodigital spectrum disorders, which also includes otopalatodigital syndrome type 1, otopalatodigital syndrome type 2, Melnick-Needles syndrome, and terminal osseous dysplasia. In general, these disorders involve hearing loss caused by malformations in the tiny bones in the ears (ossicles), problems in the development of the roof of the mouth (palate), and bony abnormalities involving various areas of the skeleton.

Frontometaphyseal dysplasia is distinguished from the other otopalatodigital spectrum disorders by the presence of joint deformities called contractures that restrict the movement of certain joints. People with frontometaphyseal dysplasia may also have bowed limbs, an abnormal curvature of the spine (scoliosis), and abnormalities of the fingers and hands.

Characteristic facial features may include prominent brow ridges; wide-set and downward-slanting eyes; a very small lower jaw and chin (micrognathia); and small, missing, or misaligned teeth. Some affected individuals have hearing loss.

In addition to skeletal abnormalities, individuals with frontometaphyseal dysplasia may have obstruction of the ducts between the kidneys and bladder (ureters), heart defects, or constrictions in the passages leading from the windpipe to the lungs (the bronchi) that can cause problems with breathing.

There are three types of frontometaphyseal dysplasia, known as type 1, type 2, and type 3. The three types differ in their genetic cause and the way they are inherited.