Patient 2, a 6-year-old girl, was the first born to healthy parents (both parents did not have cutaneous anomalies). The asymmetry was first noticed at birth. Psychomotor development was within normal ranges. At physical examination, she weighted 24 kg (90th percentile), with a height of 115 cm (50th percentile) and a head circumference of 49 cm (50th percentile). The hypopigmented patterns, in the form of whorls and V-shaped arrangements, were more evident in the trunk and in the back, with a linear configuration in the right lower limb. The diameter of the right lower limb was 1 cm larger than the lower left limb; the difference in the upper limb was less pronounced (0.4 cm). The right lower limb was 0.8 cm longer than the left. No hemiface involvement, cognitive delay, epilepsy, or spine anomalies had been recorded. The right femoral bone age was advanced of 1 year compared with the left.
Patient 1 was a 4-year-old male who first came to our observation at the age of 3 years, due to episodes of febrile seizures. The parents and the youngest sister were healthy and did not show cutaneous anomalies. He was born by Caesarean section with a birth weight of 3100 g. Psychomotor development was regular. At his first physical examination, he weighted 17 kg, with a height of 101 cm and a head circumference of 51 cm (all within the 50th percentile). The hypopigmented lesions, in the form of whorls, were localized on the upper side of the right trunk and showed a linear pattern in the right lower limb. Limbs were asymmetrical: the asymmetry involved the right lower limb, which was larger than the left of 1 cm in diameter, and of 0.5 cm in the right upper limb compared with its counterpart, the right lower limb was 1 cm longer than the left. No facial asymmetry was present. Apart from the hemi-body asymmetry, the patient did not show other anomalies. Neither cognitive delay nor spine anomalies were present. The right femoral bone age was 1 year older than the left side. No skin biopsy to check for genetic mosaicism was carried out.