What is oromandibular limb hypoplasia syndrome?

Oromandibular limb hypoplasia syndrome is a disorder that represents a group of rare and overlapping conditions. It is characterized by congenital malformations of the tongue, mandible and maxilla. Children with oromandibular limb hypoplasia syndrome may also have limb anomalies.

There are six specific conditions that are included under the umbrella of an oromandibular limb hypoplasia diagnosis:

• Hypo-glossia-hypodactylia syndrome: An exceptionally rare syndrome in which children have a small, but never totally absent, tongue and jaw, as well as variable limb abnormalities that can involve any limb and any number of limbs. Speech and intelligence are usually normal.
• Hanhart syndrome: A rare syndrome characterized by a small jaw and tongue and absent or malformed hands and/or feet.
• Glossopalatine ankylosis syndrome: Children with this syndrome have a tongue that is stuck to the top of their mouth. They may also have a cleft palate and various jaw abnormalities.
• Charlie M. syndrome: A syndrome in which children have hypertelorism (eyes that are far apart), may not be able to move their faces and may have a cleft palate.
• Limb deficiency spleno-gonadal fusion syndrome: As its name suggests, this syndrome results from a failure of separation of the spleen and gonads during development. Children with this syndrome also frequently have small jaws and may have several facial, dental, palatal, and limb anomalies.

All of the above conditions are very rare, and while each can involve limb abnormalities, they are variable and unpredictable. Each syndrome can also affect children to widely varying degrees. Still, there is such overlap between each that they can be described as a common disease state.

Causes

There is no agreed upon cause of oromandibular limb hypoplasia. Many genetic factors, as well as factors during pregnancy, have been considered.

In most children, there is no family history of the disease. Additionally, with the exception of some types of Moebius syndrome, the risk of your child passing the disease on to his or her children is very low.

The use of several prescription drugs during pregnancy has been reported to cause oromandibular limb hypoplasia. Those drugs include:

• Trimethobenzamide hydrochloride
• Meclizine hydrochloride
• Promethazine
• Imipramine
• Diazepam
• Chlorpromazine

Environmental factors and vascular problems during pregnancy are also possible causes.

Signs and symptoms

In addition to the visible signs and symptoms of oromandibular limb hypoplasia (including malformations of the mouth, jaw and limbs) other symptoms may include:

• Drooling
• Difficulty breathing
• Failure to thrive
• Difficulty with speech and eating
• Disability opening the mouth

Testing and diagnosis

Diagnosis is made by clinical findings suggestive of the syndrome. Your child’s physician will also recommend genetic testing and counseling for both your child and immediate family.

Additionally, a physician may order an echocardiogram to screen for possible associated heart malformations. A hearing evaluation will also be completed for children with cleft lip/palate.

Treatment

How physicians treat oromandibular limb hypoplasia depends on your child’s specific set of symptoms. Treatment may include any of the following:

• Surgery to correct the size and function of the jaw
• Surgical treatment of cleft lip/palate, if present
• Speech and feeding therapy
• Surgical correction of hand/foot malformations to improve appearance and function
• Neuropsychological support

Long-term outlook

The long-term outlook for oromandibular limb hypoplasia is generally positive as long as its manifestations are recognized early and effectively treated. Our team of specialists is experienced in caring for children with oromandibular-limb hypoplasia syndrome and has an excellent track record of success in the long-term.

Why choose us

The multidisciplinary team at CHOP is world-renowned for advancing the understanding and management of oromandibular limb hypoplasia syndrome. This team of experts has access to the most up-to-date diagnostic and treatment modalities and strives to improve the lives of every patient.