Oculo-digito-esophagoduodenal syndrome

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Oculo-digito-esophagoduodenal syndrome

Definition

Oculo-digito-esophago-duodenal syndrome (ODED) is a rare genetic disorder characterized by multiple conditions including various hand and foot abnormalities, small head (microcephaly), incompletely formed esophagus and small intestine (esophageal/duodenal atresia), an extra eye fold (short palpebral fissures), and learning disabilities.

Description

Individuals diagnosed with oculo-digito-esophagoduodenal syndrome usually have a small head (microcephaly), fused toes (syndactyly), shortened fingers (mesobrachyphalangy), permanently outwardly curved fingers (clinodactyly), an extra eyelid fold (palpebral fissures), and learning delays. Other features can include backbone abnormalities (vertebral anomalies), an opening between the esophagus and the windpipe (tracheoesophageal fistula), and/or an incompletely formed esophagus or intestines (esophageal or duodenal atresia). The syndrome was first described by Dr. Murray Feingold in 1975. The underlying cause of the different features of ODED is not fully understood. ODED is also known as Feingold syndrome, Microcephaly, mental retardation, and tracheoesophageal fistula syndrome, and Microcephaly, Mesobrachyphalangy, Microcephalyoculo-digito-esophago-duodenal (MODED) syndrome, Tracheo-esophagael fistula syndrome (MMT syndrome).

Genetic profile

The genetic cause of oculo-digito-esophago-duodenal syndrome is not fully understood. One study published in 2000 located an inherited region on the short arm of chromosome 2 that appears to cause ODED when mutated. However, it is still not clear if the features of ODED are caused by a single mutation in one gene or the deletion of several side-by-side genes (contiguous genes). Additionally, since this study is the first published molecular genetic study that has determined a specific location for ODED, it is unknown if most cases of ODED are caused by a mutation in this area or if ODED can be caused by genes at other locations as well.

Although the specific location and cause of ODED is not fully determined, it is known that ODED is inherited in families through a specific autosomal dominant pattern. Every individual has approximately 30,000-35,000 genes which tell their bodies how to form and function. Each gene is present in pairs, since one is inherited from their mother and one is inherited from their father. In an autosomal dominant condition, only one non-working copy of the gene for a particular condition is necessary for a person to experience symptoms of the condition. If a parent has an autosomal dominant condition, there is a 50% chance for each child to have the same or similar condition. Thus, individuals inheriting the same nonworking gene in the same family can have very different symptoms. For example, approximately 28% of individuals affected by ODED have esophageal or duodenal atresia while hand anomalies are present in almost 100% of affected individuals. The difference in physical findings within the same family is known as variable penetrance or intrafamilial variability.

Demographics

Oculo-digito-esophago-duodenal syndrome is a rare genetic condition. As of 2000, only 90 patients affected by ODED have been reported in the literature. However, scientists believe that ODED has not been diagnosed in many affected individuals and suggest that ODED is more common than previously thought. The ethnic origin of individuals affected by ODED is varied and is not specific to any one country or group.

Signs and symptoms

The signs and symptoms of oculo-digito-esophagoduodenal syndrome vary from individual to individual. Most (86-94%) individuals diagnosed with ODED have a small head (microcephaly) and finger anomalies such as shortened fingers (mesobrachyphalangy), permanently curved fingers (clinodactyly), and/or missing fingers. Over half of affected individuals also have fused toes (syndactyly). Between 45% and 85% of individuals affected by ODED have developmental delays and/or mental retardation. Other features can include an extra eyelid fold (palpebral fissures), ear abnormalities/hearing loss, kidney abnormalities, backbone abnormalities (vertebral anomalies), an opening between the esophagus and the windpipe (tracheoesophageal fistula) and/or an incompletely formed esophagus, or intestines (duodenal atresia seen in 20-30%).

Diagnosis

Diagnosis of oculo-digito-esophago-duodenal syndrome is usually made following a physical exam by a medical geneticist using x rays of the hands, feet, and back.

Prenatal diagnosis of ODED can sometimes be made using serial, targeted level II ultrasound imaging, a technique that can provide pictures of the fetal head size, hands, feet, and digestive tract. Ultrasound results indicative of ODED include a "double bubble" sign suggesting incompletely formed intestines (duodenal atresia) and small head size (microcephaly). Diagnosis by ultrasound before the baby is born is difficult. Prenatal molecular genetic testing is not available as of 2001.

Treatment and management

Since oculo-digito-esophago-duodenal syndrome is a genetic disorder, no specific treatment is available to remove, cure, or fix all conditions associated with the disorder. Treatment for ODED is mainly limited to the treatment of specific symptoms. Individuals with incompletely formed intestinal and esophageal tracts would need immediate surgery to try and extend and open the digestive tract. Individuals with learning difficulties or mental retardation may benefit from special schooling and early intervention programs to help them learn and reach their potential.

Prognosis

Oculo-digito-esophago-duodenal syndrome results in a variety of different physical and mental signs and symptoms. Accordingly, the prognosis for each affected individual is very different.

Individuals who are affected by physical hand, head, or foot anomalies (with no other physical or mental abnormalities) have an excellent prognosis and most live normal lives.

Babies affected by ODED who have incomplete esophageal or intestinal tracts will have many surgeries and prognosis depends on the severity of the defect and survival of the surgeries.

Resources

BOOKS

Children with Hand Differences: A Guide for Families. Area Child Amputee Center Publications. Center for Limb Differences in Grand Rapids, MI, phone: 616-454-4988.

PERIODICALS

Piersall, L. D., et al. "Vertebral anomalies in a new family with ODED syndrome." Clinical Genetics 57 (2000): 444-4448.

ORGANIZATIONS

Cherub Association of Families & Friends of Limb Disorder Children. 8401 Powers Rd., Batavia, NY 14020. (716) 762-9997.

EA/TEF Child and Family Support Connection, Inc. 111 West Jackson Blvd., Suite 1145, Chicago, IL 60604-3502. (312) 987-9085. Fax: (312) 987-9086. [email protected]. <http://www.eatef.org/>.