Becker Naevus Syndrome Associated With a Mosaic Pathogenic Variant in ACTB
Becker naevus syndrome hyperpigmented patch increased hair growth café-au-lait macule marfanoid phenotype scoliosis joint hypermobility skin laxity pectus excavatum mitral valve prolapse tachyarrhythmias ACTB gene cell migration cell signaling cell proliferation Becker's nevus hyperpigmentation hair growth café-au-lait spot marfanoid features curved spine flexible joints loose skin sunken chest heart valve issues irregular heartbeat
TLDR A girl with Becker naevus syndrome has a genetic variant in the ACTB gene related to her symptoms.
A 15-year-old girl with a history of a hyperpigmented patch with increased hair growth on her left flank and a café-au-lait macule on her right lower back was diagnosed with Becker naevus syndrome. She exhibited a marfanoid phenotype, including scoliosis, joint hypermobility, skin laxity, pectus excavatum, mitral valve prolapse, and tachyarrhythmias. Genetic testing revealed a de novo mosaic pathogenic variant in the ACTB gene, which has been associated with Becker naevi and Becker naevus syndrome. This variant is involved in cell migration, signaling, and proliferation. The patient's symptoms, including skeletal and soft tissue abnormalities, align with the rare syndrome's characteristics. The case emphasizes the importance of DNA analysis from skin for diagnosis and suggests the need for counseling and screening for associated conditions due to the syndrome's heterogeneous extracutaneous phenotypes.
