Spectrum of skeletal abnormalities in a complex malformation syndrome with "cutis tricolor" (Ruggieri-Happle syndrome).

BACKGROUND

The term cutis tricolor describes the combination of congenital hyper- and hypopigmented skin lesions in close proximity to each other in a background of normal complexion. This phenomenon has been reported: (i) as a purely cutaneous trait; (ii) as a part of a complex malformation syndrome (Ruggieri-Happle syndrome - RHS); (iii) as a distinct type [cutis tricolor parvimaculata]; (iv) in association with other (e.g. vascular) skin disturbances.

OBJECTIVES

To delineate the spectrum of skeletal defects in cutis tricolor.

METHODS

Retrospective and prospective analysis of skeletal surveys in 14 subjects (eight men; six women; aged 2-28 years) with cutis tricolor [4 purely cutaneous trait; 10 syndromic (RHS)].

RESULTS

Bone abnormalities were recorded in 71.4% (10/14) of patients [100% (10/10) of cases with (other-than-skeletal) extra-cutaneous manifestations vs. null (0/4) in cases with purely cutaneous traits] and included overall small skull (n = 6); prognathism (n = 6); 'J'-shaped pituitary fossa (n = 1); absence of atlas posterior arch (n = 3); frontal bossing (n = 6); scoliosis (n = 9) with kyphosis (n = 6) and/or lordosis (n = 6); vertebral (n = 9) and ribs (n = 4) defects. Negative ZFHX1B gene analyses excluded overlaps with Mowat-Wilson syndrome.

CONCLUSIONS

Cutis tricolor may be a marker of underlying skeletal involvement particularly in subjects with a complex syndromic (RHS) phenotype.