V‐Shaped Hyperpigmented Linear Lesions, Patchy Hypotrichosis, and Teeth Abnormalities in a Young Girl

Abstract

A 22-year-old woman presented to our Department complaining of linear hypopigmented lesions on the trunk and extremities as well as mild patchy hypotrichosis on the occipital area since infancy. Her medical history was significant for congenital dental abnormalities (hypodontia with conical-shaped teeth) that had been treated with orthodontic management and dental implants (Fig. 1). No consanguinity or similar abnormalities were recorded in the family.The patient described generalized xerosis and was aware of having hyperpigmented linear areas that were more visible after suntanning. She did not complain of reduced sweating.Physical examination revealed a fair-haired woman with scanty fine hair and an irregularly shaped occipital area of hypothrichosis. In the abnormal zone, the hair was thin and brittle with a whorly implantation (Fig. 2). Discrete eyebrow hypothrichosis was also noted. Linear hypopigmented streaks following a V-shaped pattern, intermingled with areas of normal skin, were observed on her back (Fig. 3). In addition, after a close examination, a patchy absence of vellus hair and stripes of hypotrichosis along the limbs were noted. No associated nail abnormalities were detected. A skin biopsy specimen taken from the transitional lines showed a segmental loss of eccrine sweat glands. WHAT SYNDROME IS THIS?Expression mosaicism of X-linked hypohidrotic ectodermal dysplasia. ADDITIONAL STUDIESA starch-iodine test was performed on the patient's back, demonstrating a linear distribution of nonfunctioning sweat glands along Blaschko lines (Fig. 4). Active sweat pores were evidenced by the appearance of minute dark spots. Genetic StudyMutation analysis of the ED1 gene from genomic DNA was performed in our patient. After direct DNA sequencing, a 8-bp duplication in exon 1 of ED1 gene [c.64_71dup8] resulting in a frameshift and premature stop codon [p.Cys25AlafsX34] was demonstrated.