Michelin Tire Baby Syndrome (MTBS) is an autosomal dominant rare genodermatosis disorder characterized by generalized folding of excess skin. This skin folding may be isolated, or associated with additional phenotypic abnormalities and probably reflect multiple underlying disorders. Circumferential skin fold is a rare finding at birth. In MTBS, multiple, symmetric, ring-like lesions involving the extremities and trunk are seen in a benign hamartomatous form. In some cases, the palms and soles may also be involved. The name of the condition comes from the cartoon mascot of the Michelin Tire Company. Affected individuals may also exhibit intellectual disability, cleft palate, and dysmorphic features.
Skin biopsies of affected patients may show nevus lipomatosis, smooth muscle hamartoma, degenerative collagen, and/or scarring. Treatment is conservative. The skin folds themselves usually tend to disappear as the child gets older. However, the other associated features of the syndrome, including developmental delays need to be managed.
Most familial cases of CSCSC1 follow an autosomal dominant mode of inheritance. In some cases, older family members may also show remnants of skin folds.
Mutations in the TUBB (Tubulin Beta Class I) gene are known to be associated with CSCSC1. This gene encodes a beta tubulin protein, which acts as a structural component of microtubules. It is not clear how mutations in this gene lead to MTBS. However, these mutations have been shown to compromise microtubule dynamics.
Farooqi et al. (2010) studied a 2-month old girl with MTBS born to Saudi-Filipino parents. Clinical examination revealed multiple, asymmetric, deep, gyrate skin folds involving extremities and shoulders. She had a characteristic round face with hypertelorism, depressed nasal bridge and a thin, downturned vermillion border of upper lip. There was no hypertrichosis and no other cutaneous or extracutaneous abnormalities were noted. Anthropometric measurements were within normal limits. Systemic examination was unremarkable. None of her family members had history of similar skin folds. Baseline investigations did not reveal any abnormal findings and ultrasound of abdomen and pelvis were normal.