Familial Michelin Tire baby syndrome

Abstract

Sir, Michelin tire baby syndrome (MTBS) is a rare genodermatosis first described by Ross[1] that is characterized clinically by multiple, symmetric, ring-like lesions involving the extremities and the trunk. We report a rare case of familial MTBS. A male child aged 10 months was referred to our outpatient department with asymptomatic skin folds noticed along both the upper and lower limbs since birth. There was a gradual and progressive increase in the number and size of skin folds with time. The baby was delivered normally at term and weighed 3 kg. Growth and development were normal. The anthropometric measurements and developmental milestones were within normal limits. Craniofacial anomalies, such as hypertelorism and depressed nasal bridge, were noticed [Figure 1]. General physical and systemic examinations were unremarkable. Figure 1 Mild hypertelorism and depressed nasal bridge Cutaneous examination of the child revealed multiple, symmetric, deep, gyrate skin creases on the forearms, dorsum of the hands, buttocks, thighs, and legs with sparing of the trunk and neck [Figures 2a, 2b and 3]. Pseudo-Darier's sign was negative. Hair, nail, and mucosa were normal. There was no restriction of neck or limb movements. Figure 2 (a) Bilateral, symmetrical, concentric skin folds over the ventral aspect of lower limbs; (b) bilateral, symmetrical, concentric skin folds over the dorsal aspect of lower limbs Figure 3 Bilateral, symmetrical, gyrate skin folds involving upper limbs The parents were first cousins and were in good health. It was a first pregnancy and was free from any complications. The mother had similar history of asymptomatic constrictions bands on the neck, upper and lower limbs at birth. Spontaneous resolution was noticed by 5 years of age except for few residual bands on the neck [Figure 4], which were asymptomatic. Figure 4 Remnant of skin folds on the neck Skin biopsy could not be done for obvious reasons. Based on the history and clinical features, it was diagnosed as a case of MTBS. The parents were informed of the benign nature of the disorder. Periodic follow up was recommended at our unit, but unfortunately the patient was lost to follow-up. MTBS is a rare genetic syndrome characterized by excessive folding of the skin. The patients resemble the mascot of a French tyre manufacturer.[1] MTBS is characterized by multiple, congenital, asymptomatic, symmetric, circumferential skin folds. Most common sites are the extremities. Trunk, palms, and soles may also be involved. Such folds may be associated with hypertrichosis.[2] MTBS has been associated with various congenital anomalies. Facial dysmorphism, including bilateral epicanthic folds,[2] low-set ears, hypoplastic teeth and mandible, cleft lip and cleft palate have been described with MTBS.[2] Hypertelorism and depressed nasal bridge have been noticed in our case. Systemic anomalies include developmental delay, seizures, congenital heart disease, and undescended testis with abnormal histology.[2 3] Our case had none of these systemic abnormalities. Familial cases of MTBS suggesting autosomal dominant mode of inheritance has been reported in the literature.[4] Paracentric inversion of long arm of chromosome 11[5] and deletion of short arm of chromosome 7[6] has been reported in association with MTBS. As noticed in our case, older family members may have remnants of the skin folds. The pathogenesis of MTBS is unclear. MTBS is also known as congenital diffuse lipomatosis[1] as the dermatomegaly may be due to a diffuse lipomatous nevus in the deeper dermis. Smooth muscle hamartoma has also been noticed in few cases.[2] Abnormal elastic fiber formation has also been thought to be a predisposing factor as reported by Sato et al.[7] Burgdrof et al. has reported scarring in a case of MTBS.[8] It is now thought that MTBS may not be an isolated disorder. Rather, it may be a clinical finding associated with other disorders. Beare–Stevenson cutis gyrata syndrome is associated with dermatomegaly localized to scalp, forehead, face, and neck.[9] Skin folds may be a part of amniotic band sequence in association with mutiple congential skin creases. Other known associations include HITCH syndrome[10] (hearing impairment, undescended testis, circumferential skin creases, and mental handicap) and MCA/MR syndrome[11] (multiple congenital anomalies and mental retardation syndrome). Ainhum, which presents as a constricting ring at the digitoplantar fold of the fifth toe, can be considered as the closest differential diagnosis. It usually progresses to spontaneous amputation of the digit in adulthood, a feature not seen in MTBS. Sardana et al. have reported a case of spontaneously improving MTBS.[12] Palit et al. have reported a second case of MTBS from India.[13] To the best of our knowledge, this is the first case of familial MTBS being reported from India.