Feingold syndrome is a rare, inherited disorder recognized by anomalies affecting the fingers, toes, facial structure, and gastrointestinal tract. Arising from genetic changes that impact development before birth, its features can vary significantly from one person to another. Despite this variability, a consistent pattern of signs allows for its identification. The syndrome can also be associated with developmental delays, though the extent of this varies.
Symptoms of Feingold Syndrome
The clinical presentation of Feingold syndrome is defined by distinct physical traits. Limb anomalies include brachymesophalangy, the shortening of the middle bone in the second and fifth fingers, and clinodactyly, a curving of the fifth finger. In the feet, syndactyly, or the webbing of toes, is frequently observed, most often between the second and third or fourth and fifth toes.
Craniofacial features are also prominent. Affected individuals may have microcephaly, where the head circumference is smaller than expected, and short palpebral fissures, meaning narrow eye openings. Some may also exhibit ptosis, a drooping of the upper eyelids.
Malformations of the gastrointestinal system are among the most serious manifestations. Esophageal atresia, where the esophagus fails to connect to the stomach, and duodenal atresia, a blockage in the small intestine, occur in about half of all cases. A tracheoesophageal fistula, an abnormal connection between the trachea and esophagus, can also be present. These conditions are life-threatening and require immediate surgical correction.
The impact on cognitive development is variable. Some individuals with Feingold syndrome have mild to moderate learning difficulties, while many others have intelligence within the normal range. The presence and severity of all symptoms can differ greatly, highlighting the disorder’s broad clinical spectrum.
Genetic Causes and Inheritance Patterns
Two distinct types of Feingold syndrome are identified by their molecular cause. The most common form, Feingold syndrome type 1 (FS1), is caused by mutations or deletions in the MYCN gene on chromosome 2. This gene provides instructions for a protein involved in embryonic development, and disruptions to it cause the syndrome’s features.
A rarer form, Feingold syndrome type 2 (FS2), is caused by the loss of a small piece of chromosome 13 containing the MIR17HG gene. Individuals with FS2 share many limb and facial features of FS1, such as microcephaly and toe syndactyly. However, they notably lack the serious gastrointestinal atresias.
The condition is passed down in an autosomal dominant inheritance pattern, meaning only one copy of the altered gene is needed to cause the disorder. Each child of an affected parent has a 50% chance of inheriting the altered gene and developing the syndrome.
The syndrome can also result from a de novo mutation, a new genetic change not inherited from either parent. These spontaneous mutations occur during the formation of reproductive cells or in early embryonic development. This explains why some individuals with Feingold syndrome have no family history of the condition.
Diagnosis of Feingold Syndrome
A diagnosis of Feingold syndrome is first suspected when a newborn or child presents with a characteristic combination of its core features. A physician will conduct a thorough clinical evaluation, looking for signs of gastrointestinal obstruction alongside the distinct physical traits.
Imaging studies help investigate these physical signs. X-rays of the hands and feet can confirm skeletal abnormalities like brachymesophalangy. When gastrointestinal issues are suspected, ultrasound or MRI can be used before and after birth to detect atresias, providing evidence to support a diagnosis.
The definitive diagnosis is achieved through molecular genetic testing. A blood sample is analyzed for a pathogenic variant in the MYCN gene for type 1 or a deletion involving the MIR17HG gene for type 2. Confirming the genetic cause establishes the diagnosis and helps provide accurate genetic counseling.
Before a final diagnosis, healthcare providers consider other conditions with overlapping features. This differential diagnosis involves ruling out syndromes like VACTERL association or CHARGE syndrome, which have different underlying causes and diagnostic criteria.
Management Strategies for Feingold Syndrome
There is no cure for Feingold syndrome, so management focuses on addressing specific symptoms and providing supportive care. Treatment is tailored to each person’s needs and requires a multidisciplinary team of specialists, which may include:
- Pediatricians
- Geneticists
- Surgeons
- Various therapists
Surgical interventions are often necessary in early infancy. Gastrointestinal atresias require prompt surgery in the newborn period to correct blockages and allow for proper feeding. These procedures are complex and may require long-term follow-up to manage potential complications like gastroesophageal reflux.
A range of therapies plays a part in ongoing management. Occupational therapy helps individuals with hand and finger anomalies improve fine motor skills. Physical therapy may be recommended for gross motor skill delays, and speech therapy can assist with associated language difficulties.
Developmental and educational support is also provided. Early intervention programs can support infants and young children showing signs of developmental delay. For school-aged children with learning difficulties, an Individualized Education Plan (IEP) can provide tailored strategies and classroom support.
Regular medical monitoring is necessary throughout an individual’s life. Ongoing check-ups allow healthcare providers to manage related health issues, such as hearing loss or potential heart and kidney anomalies. This proactive approach also helps track developmental progress and ensures new challenges are addressed promptly.