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.
A 5.5-year-old girl was brought to our hospital with a complaint of disproportionate overgrowth and lengthening of the right leg accompanied by marked hypopigmented lesions over the trunk and legs, which reportedly had become noticeable by 2-weeks postpartum and gradually increased and spread. She was born to non-consanguineous parents and had been under monitoring for delayed speech. On examination, her height and weight were 110 cm (10th to 25th percentile) and 23 kg (75th to 90th percentile), respectively. The dermatological examination was remarkable for hypopigmented patches following the Blaschko lines over the trunk and both legs, more prominently on the right leg (, ), which was thicker and longer (~2 cm) than the left (). Apart from these findings, the systemic examinations, routine haemogram and biochemical tests, and magnetic resonance scans of the cranium and lower extremities were normal. When the Denver Developmental Screening Test was administered for speech delay, it was graded as ‘delayed’, correlating with the age of 3.5 years. After consultation with the dermatology department, a skin biopsy was considered unnecessary.