Patient 3, a 10-year-old boy, was born by normal delivery. His parents did not show cutaneous anomalies. He was admitted for consultation due to episodes of generalized tonic-clonic seizures lasting several minutes: seizures had started at age 2 years. He showed neurodevelopmental delay from his first months of life: his current school performance is poor. An electroencephalographic (EEG) examination revealed spike and wave discharges in the temporal and parietal regions. Treatment with sodium valproate substantially reduced the frequency of seizures. At physical examination, he weighted 34 kg, with a height of 141 cm (75th percentile). The hypopigmented lesions were localized in the thorax and in the back, mainly on the left side. The diameter of the sural region of the lower left limb was 8 cm larger than the contralateral, and the diameter of the biceps region of the left limb was 3 cm larger than the contralateral. The left lower limb was 2 cm longer than the right. The asymmetry involved also the left hemiface. A lower-limb MRI showed increased growth in both long bones and soft tissues. Mild thoracolumbar right kyphoscoliosis was noticed. Brain MRI and ophthalmologic examination were both normal.
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.