Feingold Syndrome 1

Clinical characteristics: Feingold syndrome 1 (referred to as FS1 in this GeneReview) is characterized by digital anomalies (shortening of the 2nd and 5th middle phalanx of the hand, clinodactyly of the 5th finger, syndactyly of toes 2-3 and/or 4-5, thumb hypoplasia), microcephaly, facial dysmorphism (short palpebral fissures and micrognathia), gastrointestinal atresias (primarily esophageal and/or duodenal), and mild-to-moderate learning disability.

Diagnosis/testing: The diagnosis of FS1 is established in a proband with suggestive clinical findings and a heterozygous pathogenic variant in MYCN identified by molecular genetic testing.

Management: Treatment of manifestations: Gastrointestinal atresia is treated surgically. Mild-to-moderate learning disabilities are treated in the usual manner.

Genetic counseling: FS1 is inherited in an autosomal dominant manner. Approximately 60% of individuals with Feingold syndrome 1 have an affected parent; the proportion of FS1 caused by a de novo MYCN pathogenic variant is unknown. Each child of an individual with FS1 has a 50% chance of inheriting the MYCN pathogenic variant. When the MYCN pathogenic variant has been identified in an affected family member, prenatal and preimplantation genetic testing are possible.