Strømme Syndrome

CLINICAL CHARACTERISTICS

Strømme syndrome is a clinically variable disorder characterized primarily by small bowel intestinal atresia (including apple peel intestinal atresia), microcephaly, developmental delay and/or intellectual disability, structural brain anomalies, and ocular, genitourinary, and cardiac anomalies. A highly variable clinical presentation is observed among affected individuals that may range from mid-gestation lethality, to multisystem involvement with features implicated in the ciliopathies, to nonsyndromic microcephaly with developmental delay. Apple peel intestinal atresia, a rare form of small bowel atresia involving the proximal jejunum near the ligament of Treitz, occurs in some individuals. Intestinal atresia in individuals with Strømme syndrome can involve the duodenum, jejunum, or multiple segments.

DIAGNOSIS/TESTING: The diagnosis of Strømme syndrome is established in a proband with characteristic features and biallelic pathogenic variants identified by molecular genetic testing.

MANAGEMENT

Individualized care by a multidisciplinary team; surgical treatment of gastrointestinal atresia; developmental and educational support; standard treatment for ocular anomalies, vision issues, renal anomalies, and cardiac anomalies; social work involvement and care coordination as needed. Assess growth, feeding, and development at each visit. Follow up for ophthalmologic manifestations and vision issues as recommended by ophthalmologist and low-vision clinic.

GENETIC COUNSELING

Strømme syndrome is inherited in an autosomal recessive manner. If both parents are known to be heterozygous for a pathogenic variant, each sib of an affected individual has at conception a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Once the pathogenic variants have been identified in an affected family member, carrier testing for at-risk relatives and prenatal/preimplantation genetic testing are possible.