Costello syndrome

Costello, 1971

Costello syndrome (OMIM 218040) is a very rare (about 220-300 cases have been described so far), genetically caused complex malformation syndrome that belongs to the RASopathies.

m:w=1:1; so far less than 300 cases have been described worldwide.

Mutations of the HRAS gene (see RAS below), a regulator gene that codes for the Ras protein, have been detected. This protein is a central regulator of various signal transduction pathways that regulate growth and differentiation processes (see also RASopathies)

Heart abnormalities, failure to thrive, dwarfism; coarsened facial features, mental retardation; hyperflexible joints.

Skin lesions: Facial and perianal localized skin-coloured, wart-like papules and plaques, diffuse palmo-plantar hyperkeratosis with rhagades on the heels, hyperhidrosis palmaris et plantaris; hyperpigmented rough, hyperkeratotic plaques on the back of the foot and dorsal sides of the toes, acanthosis nigricans with infestation of the axillae. In some patients a mild cutis laxa was found. Furthermore frontotemporal alopecia, trichomegaly,curly hair and nail dystrophies.

Palmoplantar keratoses are accompanied by a velvety aspect, strikingly pronounced hand lines and accentuation of the skin ridges at the fingertips (tripe palms).

The disease is associated with a disposition to the development of neoplasia. These include: rhabdomyosarcoma, neuroblastoma, urothelial carcinoma.

1. Costello JM (1971) A new sydrnome. NZ Med J 74:397
2. Wirtz M et al (2015) Costello syndrome, a rare RASopathy with cutaneous symptoms. Dermatologist 66:225-228